v2.6.1

Add new documentation

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "vendor/traceur"]
+	path = vendor/traceur
+	url = https://github.com/google/traceur-compiler
+[submodule "vendor/regenerator"]
+	path = vendor/regenerator
+	url = https://github.com/facebook/regenerator

.jshintignore

@@ -1,3 +1,3 @@
 node_modules
 test
-lib/6to5/templates
+lib/6to5/transformation/templates

.npmignore

@@ -1,7 +1,7 @@
 node_modules
 *.log
 *.cache
-lib/6to5/templates
+lib/6to5/transformation/templates
 test
 benchmark
 Makefile

CHANGELOG.md

@@ -1,239 +1,470 @@
-# 1.14.6
+# Changelog
+
+> **Tags:**
+> - [New Feature]
+> - [Bug Fix]
+> - [Spec Compliancy]
+> - [Breaking Change]
+> - [Documentation]
+> - [Internal]
+> - [Polish]
+
+_Note: Gaps between patch versions are faulty/broken releases._
+
+## 2.6.1
+
+ * **Bug Fix**
+  * Fix rest parameter arguments key.
+
+## 2.6.0
+
+ * **Bug Fix**
+  * Better handling of number literal property keys.
+  * Handle `NewExpression` paren insertion edegcases better.
+ * **Internal**
+  * Fix incorrect AST node `identifier("this")`.
+  * Better `toIdentifier` method that handles reserved words.
+  * Upgrade `acorn-6to5`.
+    * Fix exponentiation operator precedence.
+    * Fix line terminators after async contextual keywords.
+    * Add semicolons as class elements inside of a class body.
+  * Upgrade to `core-js` 4.0.0.
+  * Upgrade to `regenerator` 0.8.3.
+    * Fix non-loop labeled statements.
+ * **New Feature**
+  * Basic destructuring defaults
+  * Add `.es` to list of supported extensions.
+  * Add optional `typeofSymbol` transformer.
+  * Use a `for` loop for rest parameters instead of `Array.prototype.slice`.
+ * **Polish**
+  * Move `"use strict";` to inside module bodies instead of at the top of the file.
+  * Better handling of dynamic imports.
+ * **Spec Compliancy**
+  * Class inheritance now has a `function` or `null` type check.
+  * Add `interopRequireWildcard` around wildcard imports and exports to handle non-object exports.
+
+## 2.5.0
+
+ * Remove `noDuplicateProperties` transformer.
+ * Better generated UIDs based on nodes.
+ * Default parameters now use `arguments[i]`, conditionals and variable declarations instead of using long-form if statements.
+
+## 2.4.10
+
+ * Upgrade `acorn-6to5`.
+
+## 2.4.9
+
+ * Upgrade `acorn-6to5`.
+ * Add optional `protoToAssign` transformer.
+ * Fix missing properties from computed property keys.
+ * Make ES7 comprehensions `let` variables.
+
+## 2.4.8
+
+ * Make `require("6to5/register")` work with browserify - [#370](https://github.com/6to5/6to5/pull/370). Thanks [@hughsk](https://github.com/hughsk)!
+
+## 2.4.7
+
+ * Upgrade `acorn-6to5`.
+
+## 2.4.6
+
+ * Move `coreAliasing` and `undefinedToVoid` transformers down to catch `moduleFormatter` transforms.
+
+## 2.4.5
+
+ * Avoid printing comments if they've already been output.
+
+## 2.4.4
+
+ * Add `module` type to browser build `<script>` handler.
+ * Fix some `MemberExpression` modifying incorrectly setting `property` to a `MemberExpression`.
+
+## 2.4.3
+
+ * Upgrade `acorn-6to5`.
+ * Add support for `FunctionDeclaration`s in `bluebirdCoroutines` and `asyncToGenerators` transformers.
+
+## 2.4.2
+
+ * Upgrade `acorn-6to5`.
+ * Better uids generated for various transformers based on parent node.
+ * Alias flat references in `coreAliasing` transformer.
+
+## 2.4.1
+
+ * Better whitespace handling of parenthesized expressions due to trailing comments.
+ * Fix `yield` inside of comprehensions.
+
+## 2.4.0
+
+ * Use a closure always for classes with a super.
+ * Always use native loops for array comprehensions.
+ * Allow `yield` inside of comprehensions.
+ * Add optional `bluebirdCoroutine` transformer.
+ * Add optional `asyncToGenerator` transformer.
+ * Move `useStrict` transformer to before `_moduleFormatter` causing `"use strict";` to always be placed the very top.
+
+## 2.3.2
+
+ * Add parens on expressions with trailing comments.
+
+## 2.3.1
+
+ * Add `undefinedToVoid` optional transformer.
+ * Use `Object.defineProperty` for computed properties.
+
+## 2.3.0
+
+ * Upgrade `acorn-6to5`.
+ * Support circular references and hoist variable declarations in `system` module formatter.
+ * Add optional transformers, including a new `coreAliasing` transformer that aliases native ES6 static properties to their `core-js` equivalent.
+
+## 2.2.0
+
+ * Make `system` module formatter modules anonymous by default.
+ * Fix duplicate comments being output, breaking code.
+
+## 2.1.0
+
+ * Add `cache` option to register hook.
+ * Update `core-js`.
+ * Fix starting newline not being added on case statements.
+ * Fix destructuring `VariableDeclaration`s not inside `BlockStatement`s and `Program`.
+
+## 2.0.4
+
+ * Avoid being greedy when destructuring array iterables.
+
+## 2.0.3
+
+ * Hoist function declarations in system module formatter for circular references.
+ * Hoist default function declarations in umd and amd module formatters for circular references.
+
+## 2.0.2
+
+ * Inherit comments in `for-of` transformer.
+ * Remove `interopRequire` from `system` module formatter.
+
+## 2.0.1
+
+ * Remap `UpdateExpression` module export binding.
+ * Fix automatic closure on `PrivateDeclaration` in classes.
+
+## 2.0.0
+
+ * Make string literal generation only escapes unicode that it has to.
+ * Internal code generation format options have been exposed.
+ * Change playground method binding operator from `:` to `#` removing ambiguous syntax with terns.
+ * Fix rest parameters in async and generator functions.
+ * Export/import declarations replace by the modules transformer now inherit comments.
+ * Added playground flag to `6to5-node`.
+ * `6to5-node` now behaves the same as `node`.
+ * `6to5-node` now uses `kexec` to become the forked process to correctly propagate signals on unix.
+ * Constants are now block scoped.
+ * Exposed ast transformer.
+ * Merged `commonInterop` and `common` module formatters.
+ * Fix generator comprehensions not inheriting `arguments`, `this` etc.
+ * Object and class mutator shorthand are now enumerable.
+ * Remove regenerator `Generator has already finished` error which isn't spec-compliant.
+ * Expose internal `spec` transformers that nicen up code output.
+ * Add export variable declaration default initializers.
+ * Propagate export declaration reassignments.
+ * Add initializer default to block scoped variable declarations within a loop.
+ * Flow type support.
+ * Make async/await contextual keywords.
+ * Allow `yield`ing of non-objects.
+ * Class declarations now lack an IIFE.
+ * Support falsy and `null` super classes.
+ * Add support for experimental abstract references `private` declarations.
+ * Leave out IIFE for class declarations.
+ * Switched to [core-js](https://github.com/zloirock/core-js) from [es6-symbol](https://github.com/medikoo/es6-symbol) and [es6-shim](https://github.com/paulmillr/es6-shim/) for built-in polyfill.
+ * `amd` and `umd` module formatters now behave the same as `common` with `interopRequire`.
+ * Micro-optimizations to boost performance by 200%.
+ * Rename module formatter methods `import` to `importDeclaration` and `export` to `exportDeclaration`.
+ * Support multiple declarators in export variable declarations.
+ * Freeze tagged template literal object.
+ * Remove inlined `regenerator` fork.
+ * Remove `ParenthesizedExpression`.
+ * Rename `object-spread` helper to `object-without-properties`.
+ * Rename `class-props` helper to `prototype-properties`.
+ * Rename `extends` helper to `inherits`.
+ * Completely rewritten `system` module formatter.
+
+## 1.15.0
+
+ * Don't alias `GeneratorFunction` and check the name which causes minifiers to remove the name and throw an error later on when we check if it's set.
+
+## 1.14.18
+
+ * Fix files only containg comments not being output.
+ * Fix duplicate comments on property key shorthands.
+
+## 1.14.17
+
+ * Add default initializer to let variables within loop bodies.
+ * Fix excessive `break` replacement inside of switches in let scoping.
+
+## 1.14.16
+
+ * Add object getter memos and this shorthand to playground.
+ * Fix while loops in let scoping.
+ * Upgrade `acorn-6to5`.
+
+## 1.14.14
+
+ * Fix template literals escaping.
+
+## 1.14.13
+
+ * Fix let scoping of `while` loops.
+ * Make class methods enumerable.
+
+## 1.14.12
+
+ * Fix duplicate dynamic expressions in call spread.
+
+## 1.14.10
+
+ * Fix let scoping unneccesary override.
+
+## 1.14.6
 
  * Avoid ensuring a block on non-array node replacements.
 
-# 1.14.5
+## 1.14.5
 
  * Upgrade `acorn-6to5`.
  * Fix JSON recursion error for unknown code generator node types.
  * Ensure that a statement is a block on block/statement types when replacing them with multiple nodes.
 
-# 1.14.4
+## 1.14.4
 
  * Merge pretzel maps and method binding.
 
-# 1.14.3
+## 1.14.3
 
  * Add playground pretzel maps.
 
-# 1.14.2
+## 1.14.2
 
  * Fix `commonInterop` default export handling.
  * Fix keyworded property key identifiers being turned into computed property key literals.
 
-# 1.14.1
+## 1.14.1
 
  * Inherit comments from `ClassDeclaration`.
 
-# 1.14.0
+## 1.14.0
 
  * Add [playground](https://6to5.github.io/playground.html).
 
-# 1.13.13
+## 1.13.13
 
  * Fix `--debug` in `bin/6to5-node`. Thanks [@timoxley](https://github.com/timoxley).
 
-# 1.13.12
+## 1.13.12
 
  * Ignore `XJSEmptyExpression`s in `react` transformer output.
 
-# 1.13.11
+## 1.13.11
 
  * Fix `util.regexify` on falsy values.
  * Fix `_aliasFunction` with rest parameters.
  * Export as `module.exports` instead of `exports.default` if there are no other `ExportDeclaration`s in `commonInterop` module formatter.
  * Add `system` module formatter. Thanks [@douglasduteil](https://github.com/douglasduteil).
 
-# 1.13.10
+## 1.13.10
 
  * Add support for `AssignmentExpression` destructuring outside of `ExpressionStatement`.
 
-# 1.13.9
+## 1.13.9
 
  * Fix `VirtualPropertyExpression` visitor keys.
 
-# 1.13.8
+## 1.13.8
 
  * Only use a single reference in abstract references.
 
-# 1.13.7
+## 1.13.7
 
  * Upgrade `acorn-6to5`.
  * Add experimental exponentiation operator support.
 
-# 1.13.6
+## 1.13.6
 
  * Fix experimental object spread/rest helper.
 
-# 1.13.5
+## 1.13.5
 
  * Upgrade `acorn-6to5`.
  * Add experimental support for object spread/rest.
  * Change `arguments` to array to an additional helper method.
 
-# 1.13.4
+## 1.13.4
 
  * Fix single spread element returning itself.
 
-# 1.13.3
+## 1.13.3
 
  * Upgrade `acorn-6to5`.
  * Add experimental support for abstract references.
 
-# 1.13.2
+## 1.13.2
 
  * Optimise `Array.from` usage by adding a helper method.
  * Upgrade `acorn-6to5`.
 
-# 1.13.1
+## 1.13.1
 
  * Fix constructor spread optimisation. Thanks [@zloirock](https://github.com/zloirock).
 
-# 1.13.0
+## 1.13.0
 
  * Put experimental ES7 features behind a flag `--experimental` and `experimental` option.
  * Constructor spread performance increase. Thanks [@RReverser](https://github.com/RReverser).
  * Use `self` instead of `window` in the optional 6to5 runtime. Thanks [@RReverser](https://github.com/RReverser).
 
-# 1.12.26
+## 1.12.26
 
  * Support computed property destructuring.
 
-# 1.12.25
+## 1.12.25
 
  * Update `acorn-6to5`, `ast-types`, `es6-shim`, `chokidar`, `estraverse` and `private`.
 
-# 1.12.24
+## 1.12.24
 
  * Collect references that haven't been declared in scope.
 
-# 1.12.23
+## 1.12.23
 
  * Fix generator function export hoisting.
 
-# 1.12.22
+## 1.12.22
 
  * Update `fs-readdir-recursive` and `chokidar`.
  * Support array destructuring on iterables.
  * Make amd module id optional. Thanks [@webpro](https://github.com/webpro).
 
-# 1.12.21
+## 1.12.21
 
  * Fix unneccesary let scoping replacement.
  * Add `commonInterop` module formatter. Thanks [@Naddiseo](https://github.com/Naddiseo).
  * Fix `return` outside of function body bug. Thanks [@brentburg](https://github.com/brentburg).
  * Add more flexible option types.
 
-# 1.12.20
+## 1.12.20
 
  * Append `sourceMappingURL` when using `bin/6to5` and output sourcemaps.
 
-# 1.12.19
+## 1.12.19
 
  * Add `comments` option and `--remove-comments` flag. Thanks [@webpro](htps://github.com/webpro).
  * Embed `regenerator`.
 
-# 1.12.18
+## 1.12.18
 
  * Use `global` reference instead of `window`.
 
-# 1.12.17
+## 1.12.17
 
  * Add `moduleName`, `sourceRoot` and `filenameRelative` options. Thanks [@darvelo](https://github.com/darvelo).
  * Traversal optimisations.
 
-# 1.12.16
+## 1.12.16
 
  * Fix comments not being retained from `MethodDefinition` in classes.
  * Add temporal dead zone in default parameters.
 
-# 1.12.15
+## 1.12.15
 
  * Update `acorn-6to5`.
 
-# 1.12.14
+## 1.12.14
 
  * Fix duplicate let scoping in functions.
  * Make JSX whitespace more React-compliant.
  * Add `_memberExpressionKeywords` transformer that turns keyword identifiers to computed literals.
  * Upgrade `regenerator-6to5`.
 
-# 1.12.13
+## 1.12.13
 
  * Support duplicate constants within different block scopes.
  * Fix for-head duplication testing and replacement.
  * Support `raw` property on tagged template literals.
 
-# 1.12.12
+## 1.12.12
 
  * Make scope tracker more reliable to handle all edgecases.
 
-# 1.12.11
+## 1.12.11
 
  * Block scope classes.
  * Fix generation of integer `Literal`s in `MemberExpression`.
 
-# 1.12.10
+## 1.12.10
 
  * Fix let scoping var hoisting.
 
-# 1.12.9
+## 1.12.9
 
  * Escape unicode characters when generating string `Literal`s.
  * Fix semicolons being output for statements in `ExportDeclaration`.
  * Fix `WithStatement` missing parenthesis.
 
-# 1.12.8
+## 1.12.8
 
  * Temporarily forbid `AssignmentExpression` destructuring outside of `ExpressionStatement`.
 
-# 1.12.7
+## 1.12.7
 
  * Update to latest `acorn-6to5`.
 
-# 1.12.6
+## 1.12.6
 
  * Update to latest `acorn-6to5`.
 
-# 1.12.5
+## 1.12.5
 
  * Fix excessive whitespace trimming resulting in innaccurate sourcemap line.
 
-# 1.12.4
+## 1.12.4
 
  * Add `doc` folder for documentation.
 
-# 1.12.3
+## 1.12.3
 
  * Support generator comprehensions.
  * Use `Array.from` instead of `Array.prototype.slice` in spread transformer.
  * Support spread in `NewExpression`s.
 
-# 1.12.2
+## 1.12.2
 
  * Upgrade `matcha` to `0.6.0` and `browserify` to `6.3.2`.
  * Add own `trimRight` helper instead of relying on the string instance method.
  * Support JSX spreads that aren't the first.
 
-# 1.12.1
+## 1.12.1
 
  * Fix `this` and `arguments` mapping in the `_aliasFunctions` transformer.
 
-# 1.12.0
+## 1.12.0
 
  * Combine `jsx` and `react` transformers to `react`.
  * Update `react` syntax output to React v0.12.
 
-# 1.11.15
+## 1.11.15
 
  * Fix JSX literal whitespace generation.
 
-# 1.11.14
+## 1.11.14
 
  * Avoid using a switch for let-scoping continue and break statements and use an if statement instead.
  * Remove excess whitespace and newlines from JSX literals.
 
-# 1.11.13
+## 1.11.13
 
  * Update regenerator-6to5
  * Add support for most escodegen formatting options

CODE_OF_CONDUCT.md

@@ -0,0 +1,13 @@
+# Contributor Code of Conduct
+
+As contributors and maintainers of this project, we pledge to respect all people who contribute through reporting issues, posting feature requests, updating documentation, submitting pull requests or patches, and other activities.
+
+We are committed to making participation in this project a harassment-free experience for everyone, regardless of level of experience, gender, gender identity and expression, sexual orientation, disability, personal appearance, body size, race, age, or religion.
+
+Examples of unacceptable behavior by participants include the use of sexual language or imagery, derogatory comments or personal attacks, trolling, public or private harassment, insults, or other unprofessional conduct.
+
+Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct. Project maintainers who do not follow the Code of Conduct may be removed from the project team.
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by opening an issue or contacting one or more of the project maintainers.
+
+This Code of Conduct is adapted from the [Contributor Covenant](http://contributor-covenant.org), version 1.0.0, available at [http://contributor-covenant.org/version/1/0/0/](http://contributor-covenant.org/version/1/0/0/)

CONTRIBUTING.md

@@ -1,5 +1,7 @@
 # Contributing
 
+Before contributing, please read the [code of conduct](https://github.com/6to5/6to5/blob/master/CODE_OF_CONDUCT.md).
+
  * **General**
    * No ES6 syntax features or methods, exclusively ES5.
    * Max of five arguments for functions

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 Sebastian McKenzie
+Copyright (c) 2014-2015 Sebastian McKenzie
 
 MIT License
 

Makefile

@@ -6,46 +6,7 @@ MOCHA_CMD = node_modules/mocha/bin/_mocha
 
 export NODE_ENV = test
 
-.PHONY: clean test test-cov test-clean lint test-travis test-spec test-browser publish bench build
-
-clean:
-	rm -rf coverage templates.json test/tmp dist
-
-bench:
-	npm install es6-transpiler traceur esnext es6now jstransform
-	node node_modules/matcha/bin/_matcha
-
-lint:
-	$(JSHINT_CMD) lib bin benchmark/index.js
-
-test-clean:
-	rm -rf test/tmp
-
-test:
-	make lint
-	$(MOCHA_CMD)
-	make test-clean
-
-test-cov:
-	rm -rf coverage
-	node $(ISTANBUL_CMD) $(MOCHA_CMD) --
-
-test-spec:
-	node $(ISTANBUL_CMD) $(MOCHA_CMD) -- --reporter spec
-
-test-travis:
-	make test-spec
-	if test -n "$$CODECLIMATE_REPO_TOKEN"; then codeclimate < coverage/lcov.info; fi
-
-test-browser:
-	mkdir -p dist
-
-	node bin/cache-templates
-	node bin/cache-tests
-	node $(BROWSERIFY_CMD) -e test/_browser.js >dist/6to5-test.js
-	rm -rf templates.json tests.json
-
-	test -n "`which open`" && open test/browser.html
+.PHONY: clean test test-cov test-clean lint test-travis test-spec test-browser publish bench build bootstrap
 
 build:
 	mkdir -p dist
@@ -63,6 +24,43 @@ build:
 
 	rm -rf templates.json
 
+clean:
+	rm -rf coverage templates.json test/tmp dist
+
+bench:
+	npm install es6-transpiler traceur esnext es6now jstransform
+	node node_modules/matcha/bin/_matcha
+
+lint:
+	$(JSHINT_CMD) --reporter node_modules/jshint-stylish/stylish.js lib bin benchmark/index.js
+
+test-clean:
+	rm -rf test/tmp
+
+test: lint
+	$(MOCHA_CMD)
+	make test-clean
+
+test-cov:
+	rm -rf coverage
+	node $(ISTANBUL_CMD) $(MOCHA_CMD) --
+
+test-spec:
+	node $(ISTANBUL_CMD) $(MOCHA_CMD) -- --reporter spec
+
+test-travis: test-spec
+	if test -n "$$CODECLIMATE_REPO_TOKEN"; then codeclimate < coverage/lcov.info; fi
+
+test-browser:
+	mkdir -p dist
+
+	node bin/cache-templates
+	node bin/cache-tests
+	node $(BROWSERIFY_CMD) -e test/_browser.js >dist/6to5-test.js
+	rm -rf templates.json tests.json
+
+	test -n "`which open`" && open test/browser.html
+
 publish:
 	git pull --rebase
 
@@ -83,3 +81,8 @@ publish:
 	git push --follow-tags
 
 	rm -rf templates.json browser.js runtime.js browser-polyfill.js
+
+bootstrap:
+	npm install
+	git submodule update --init
+	cd vendor/regenerator; npm install

NOTES.md

@@ -0,0 +1,8 @@
+# Notes
+
+ * Wildcard exports/imports wont normalise if `export default` is a non-object.
+
+## 3.0.0 breaking changes
+
+ * Remove `allowImportExportEverywhere` option from acorn.
+ * Remove this shorthand from playground.

README.md

@@ -3,12 +3,12 @@
 </p>
 
 <p align="center">
-  <a href="https://travis-ci.org/6to5/6to5">
-    <img alt="Travis Status" src="http://img.shields.io/travis/6to5/6to5/master.svg?style=flat&amp;label=travis">
+  <a href="https://gratipay.com/sebmck">
+    <img alt="Gratipay" src="https://img.shields.io/gratipay/sebmck.svg?style=flat">
   </a>
 
-  <a href="https://ci.appveyor.com/project/sebmck/6to5">
-    <img alt="Appveyor Status" src="http://img.shields.io/appveyor/ci/sebmck/6to5.svg?style=flat&amp;label=appveyor">
+  <a href="https://travis-ci.org/6to5/6to5">
+    <img alt="Travis Status" src="http://img.shields.io/travis/6to5/6to5/master.svg?style=flat&amp;label=travis">
   </a>
 
   <a href="https://codeclimate.com/github/6to5/6to5">
@@ -24,7 +24,11 @@
   </a>
 </p>
 
-**6to5** turns ES6+ code into vanilla ES5, so you can use next generation features **today.**
+<p align="center">
+  <strong>6to5</strong> turns ES6+ code into vanilla ES5, so you can use next generation features <strong>today.</strong>
+</p>
 
-For more information view the [documentation](https://6to5.github.io). For
-support visit the [gitter room](https://gitter.im/6to5/6to5).
+<p align="center">
+  For more information view the <a href="https://6to5.github.io">documentation</a>. For
+  support visit the <a href="https://gitter.im/6to5/6to5">gitter room</a>.
+</p>

benchmark/index.js

@@ -2,9 +2,9 @@ Error.stackTraceLimit = Infinity;
 
 var jsTrans = require("jstransform");
 var traceur = require("traceur");
-var es6tr   = require("es6-transpiler");
+//var es6tr   = require("es6-transpiler");
 var es6now  = require("es6now");
-var esnext  = require("esnext");
+//var esnext  = require("esnext");
 var to5     = require("../lib/6to5");
 
 //var uglify  = require("uglify-js");
@@ -56,12 +56,12 @@ var compilers = {
     }
   },
 
-  esnext: {
+  /*esnext: {
     runtime: readResolve("esnext/node_modules/regenerator/runtime.js") || readResolve("regenerator/runtime.js"),
     compile: function (code) {
       return esnext.compile(code).code;
     }
-  },
+  },*/
 
   es6now: {
     runtime: readResolve("es6now/runtime/ES6.js"),
@@ -70,13 +70,13 @@ var compilers = {
     }
   },
 
-  "es6-transpiler": {
+  /*"es6-transpiler": {
     compile: function (code) {
       var result = es6tr.run({ src: code });
       if (result.errors.length) throw new Error(result.join("; "));
       return result.src;
     }
-  },
+  },*/
 
   jstransform: {
     compile: function (code) {

bin/6to5-node

@@ -5,7 +5,6 @@
  * when found, before invoking the "real" _6to5-node(1) executable.
  */
 
-var spawn = require("child_process").spawn;
 var args  = ["--harmony", __dirname + "/_6to5-node"];
 
 process.argv.slice(2).forEach(function(arg){
@@ -15,15 +14,18 @@ process.argv.slice(2).forEach(function(arg){
     case "-d":
       args.unshift("--debug");
       break;
+
     case "debug":
     case "--debug":
     case "--debug-brk":
       args.unshift(arg);
       break;
+
     case "-gc":
     case "--expose-gc":
       args.unshift("--expose-gc");
       break;
+
     case "--gc-global":
     case "--harmony":
     case "--harmony-proxies":
@@ -35,20 +37,32 @@ process.argv.slice(2).forEach(function(arg){
     case "--trace-deprecation":
       args.unshift(arg);
       break;
+
     default:
-      if (0 == arg.indexOf("--trace")) args.unshift(arg);
-      else args.push(arg);
+      if (arg.indexOf("--trace") === 0) {
+        args.unshift(arg);
+      } else {
+        args.push(arg);
+      }
       break;
   }
 });
 
-var proc = spawn(process.argv[0], args, { stdio: "inherit" });
-proc.on("exit", function (code, signal) {
-  process.on("exit", function (){
-    if (signal) {
-      process.kill(process.pid, signal);
-    } else {
-      process.exit(code);
-    }
+try {
+  var kexec = require("kexec");
+  kexec(process.argv[0], args);
+} catch (err) {
+  if (err.code !== "MODULE_NOT_FOUND") throw err;
+
+  var child_process = require("child_process");
+  var proc = child_process.spawn(process.argv[0], args, { stdio: "inherit" });
+  proc.on("exit", function (code, signal) {
+    process.on("exit", function () {
+      if (signal) {
+        process.kill(process.pid, signal);
+      } else {
+        process.exit(code);
+      }
+    })
   });
-});
+}

bin/6to5-runtime

@@ -1,4 +1,4 @@
 #!/usr/bin/env node
 
-var runtime = require("../lib/6to5/runtime");
+var runtime = require("../lib/6to5/runtime-generator");
 console.log(runtime(process.argv[2]));

bin/6to5/file.js

@@ -113,16 +113,14 @@ module.exports = function (commander, filenames) {
     walk();
 
     if (commander.watch) {
-      var watcher = chokidar.watch(filenames, {
+      chokidar.watch(filenames, {
         persistent: true,
         ignoreInitial: true
-      });
-
-      _.each(["add", "change", "unlink"], function (type) {
-        watcher.on(type, function (filename) {
+      }).on("all", function (type, filename) {
+        if (type === "add" || type === "change" || type === "unlink" ) {
           console.log(type, filename);
           walk();
-        });
+        }
       });
     }
   };

bin/6to5/index.js

@@ -17,18 +17,28 @@ commander.option("-p, --playground", "Enable playground support");
 commander.option("-m, --modules [modules]", "Module formatter type to use [common]", "common");
 commander.option("-w, --whitelist [whitelist]", "Whitelist of transformers to ONLY use", util.list);
 commander.option("-b, --blacklist [blacklist]", "Blacklist of transformers to NOT use", util.list);
+commander.option("-i, --optional [list]", "List of optional transformers to enable", util.list);
 commander.option("-o, --out-file [out]", "Compile all input files into a single file");
 commander.option("-d, --out-dir [out]", "Compile an input directory of modules into an output directory");
 commander.option("-c, --remove-comments", "Remove comments from the compiled code", false);
-commander.option("-a, --amd-module-ids", "Insert module id in AMD modules", false);
+commander.option("-a, --amd-module-ids", "Insert module id in AMD modules", false); // todo: remove in 3.0.0
+commander.option("-m, --module-ids", "Insert module id in modules", false);
 
 commander.on("--help", function(){
   var outKeys = function (title, obj) {
     console.log("  " + title + ":");
     console.log();
 
+    var hasOptional = true;
+
     _.each(_.keys(obj).sort(), function (key) {
       if (key[0] === "_") return;
+
+      if (obj[key].optional) {
+        hasOptional = true;
+        key = "[" + key + "]";
+      }
+
       console.log("    - " + key);
     });
 
@@ -89,12 +99,13 @@ if (errors.length) {
 
 exports.opts = {
   sourceMapName: commander.outFile,
-  amdModuleIds:  commander.amdModuleIds,
   experimental:  commander.experimental,
   playground:    commander.playground,
+  moduleIds:     commander.amdModuleIds || commander.moduleIds,
   blacklist:     commander.blacklist,
   whitelist:     commander.whitelist,
   sourceMap:     commander.sourceMaps || commander.sourceMapsInline,
+  optional:      commander.optional,
   comments:      !commander.removeComments,
   runtime:       commander.runtime,
   modules:       commander.modules

bin/_6to5-node

@@ -1,12 +1,14 @@
 #!/usr/bin/env node
 
-var commander = require("commander");
-var path      = require("path");
-var repl      = require("repl");
-var to5       = require("../lib/6to5");
-var util      = require("../lib/6to5/util");
-var vm        = require("vm");
-var _         = require("lodash");
+var roadrunner = require("roadrunner");
+var commander  = require("commander");
+var Module     = require("module");
+var path       = require("path");
+var repl       = require("repl");
+var to5        = require("../lib/6to5");
+var util       = require("../lib/6to5/util");
+var vm         = require("vm");
+var _          = require("lodash");
 
 commander.option("-e, --eval [script]", "Evaluate script");
 commander.option("-p, --print", "Evaluate script and print result");
@@ -14,28 +16,33 @@ commander.option("-i, --ignore [regex]", "Ignore all files that match this regex
 commander.option("-x, --extensions [extensions]", "List of extensions to hook into [.es6,.js]");
 commander.option("-r, --experimental", "Enable experimental support for proposed ES7 features");
 commander.option("-g, --playground", "Enable playground support");
+commander.option("-c, --cache", "Cache compiled files and require paths");
 
 var pkg = require("../package.json");
 commander.version(pkg.version);
 commander.usage("[options] [ -e script | script.js ] [arguments]");
 commander.parse(process.argv);
 
+if (commander.cache) roadrunner.load();
+
 //
 
 to5.register({
   experimental: commander.experimental,
   extensions:   commander.extensions,
-  ignore:       commander.ignore
+  playground:   commander.playground,
+  ignore:       commander.ignore,
+  cache:        commander.cache && roadrunner.get("6to5")
 });
 
 //
 
 var _eval = function (code, filename) {
   code = to5.transform(code, {
-    modules: "commonInterop",
     filename: filename,
     blacklist: ["useStrict"],
-    experimental: commander.experimental
+    experimental: commander.experimental,
+    playground: commander.playground
   }).code;
   return vm.runInThisContext(code, filename);
 };
@@ -44,21 +51,34 @@ if (commander.eval) {
   var result = _eval(commander.eval, "eval");
   if (commander.print) console.log(result);
 } else {
-  var filenames = commander.args;
+  if (commander.args.length) {
+    // slice all arguments up to the first filename since they're 6to5 args that we handle
+    var args = process.argv.slice(2);
 
-  if (filenames.length) {
-    _.each(filenames, function (filename) {
-      if (!util.isAbsolute(filename)) {
-        filename = path.join(process.cwd(), filename);
+    var i = 0;
+    _.each(args, function (arg, i2) {
+      if (arg[0] !== "-") {
+        i = i2;
+        return false;
       }
-
-      require(require.resolve(filename));
     });
+    args = args.slice(i);
+
+    // make the filename absolute
+    var filename = args[0]
+    if (!util.isAbsolute(filename)) args[0] = path.join(process.cwd(), filename);
+
+    // add back on node and concat the sliced args
+    process.argv = ["node"].concat(args);
+
+    Module.runMain();
   } else {
     replStart();
   }
 }
 
+if (commander.cache) roadrunner.save();
+
 function replStart() {
   repl.start({
     prompt: "> ",

doc/browser.md

@@ -1,65 +0,0 @@
-# Browser
-
-A browser version of 6to5 is available from `browser.js` inside the 6to5
-directory in an npm release.
-
-## Scripts
-
-While it's not recommended for serious use, when the browser version is included
-all scripts with the type `text/ecmascript-6` and `text/6to5` are automatically
-compiled and ran.
-
-For example:
-
-```html
-<script src="node_modules/6to5/browser.js"></script>
-<script type="text/6to5">
-class Test {
-  test() {
-    return "test";
-  }
-}
-
-var test = new Test;
-test.test();
-</script>
-```
-
-## Build
-
-You can build a browser version of the compiler by running the following in the
-6to5 directory:
-
-```sh
-$ make build
-```
-
-This will output the files `dist/6to5.js` and `dist/6to5.min.js`.
-
-## Test
-
-To test 6to5 in your browser run:
-
-```sh
-$ make test-browser
-```
-
-And open `test/browser.html` in your browser if it doesn't open automatically.
-
-## API
-
-### to5.transform(code, [opts])
-
-See [options](usage.md#options) for additional documentation.
-
-```javascript
-to5.transform("class Test {}").code;
-```
-
-### to5.run(code, [opts])
-
-See [options](usage.md#options) for additional documentation.
-
-```javascript
-to5.run("class Test {}");
-```

doc/caveats.md

@@ -1,41 +1,89 @@
-# Caveats
+---
+layout: docs
+title: Caveats
+description: Just some things to keep in mind when using 6to5.
+permalink: /docs/caveats/
+redirect_from: /caveats.html
+---
+
+## Polyfills
 
 In order for certain features to work they require certain polyfills. You can
 satisfy **all** 6to5 feature requirements by using the included
-[polyfill](polyfill.md). You may alternatively selectively include what you need:
+[polyfill](polyfill.md).
 
-| Feature                     | Requirements                                                                                                                 |
-| --------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
-| Abstract References         | [experimental](usage.md#experimental), `Symbol`                                                                              |
-| Array destructuring         | `Array.isArray`, `Array.from`                                                                                                |
-| Async functions, Generators | [experimental](usage.md#experimental), [regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js) |
-| Comprehensions              | [experimental](usage.md#experimental), `Array.isArray`, `Array.from`                                                         |
-| For Of                      | `Symbol`, `prototype[Symbol.iterator]`                                                                                       |
-| Object spread/rest          | [experimental](usage.md#experimental), `Object.assign`                                                                       |
-| Spread                      | `Array.isArray`, `Array.from`                                                                                                |
+You may alternatively selectively include what you need:
 
-## Classes
+| Feature                     | Requirements                                                                                                           |
+| --------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
+| Abstract References         | [experimental](experimental.md), `Symbol`                                                                              |
+| Array destructuring         | `Array.from`                                                                                                           |
+| Async functions, Generators | [experimental](experimental.md), [regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js) |
+| Comprehensions              | [experimental](experimental.md), `Array.from`                                                                          |
+| For Of                      | `Symbol`, `prototype[Symbol.iterator]`                                                                                 |
+| Modules                     | `Object.assign`*                                                                                                       |
+| Object spread/rest          | [experimental](experimental.md), `Object.assign`                                                                       |
+| Spread                      | `Array.from`                                                                                                           |
 
-Built-in classes such as `Date`, `Array` and `DOM` cannot be subclassed due to
-limitations in ES5 implementations.
+*Only required for exporting a non-function `default` with additional `export`s.
+
+## ES5
+
+Since 6to5 assumes that your code will be ran in an ES5 environment it uses ES5
+functions. So if you're using an environment that has limited or no support for
+ES5 such as lower versions of IE then using the
+[es5-shim](https://github.com/es-shims/es5-shim) along with the
+[6to5 polyfill](polyfill.md) will add support for these methods.
+
+## Internet Explorer
+
+### Classes (10 and below)
 
 If you're inheriting from a class then static properties are inherited from it
 via [\_\_proto\_\_](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/proto),
 this is widely supported but you may run into problems with much older browsers.
 
-**NOTE:** `__proto__` is not supported on IE <= 9 so static properties
-**will not** be inherited. A possible workaround is to use `super();`:
+**NOTE:** `__proto__` is not supported on IE <= 10 so static properties
+**will not** be inherited.
+
+You can use the `protoToAssign` optional transformer that will transform all
+`__proto__` assignments to a method that will shallowly copy it over all
+properties.
 
 ```javascript
-class Foo {
-  static foo() {
-
-  }
-}
-
-class Bar extends Foo {
-  static foo() {
-    super();
-  }
-}
+require("6to5").transform("code", { optional: ["protoToAssign"] });
 ```
+
+```sh
+$ 6to5 --optional protoToAssign script.js
+```
+
+This means that the following **will** work:
+
+```javascript
+var foo = { a: 1 };
+var bar = { b: 2 };
+bar.__proto__ = foo;
+bar.a; // 1
+bar.b; // 2
+```
+
+however the following **will not**:
+
+```javascript
+var foo = { a: 1 };
+var bar = { b: 2 };
+bar.__proto__ = foo;
+bar.a; // 1
+foo.a = 2;
+bar.a; // 1 - should be 2 but remember that nothing is bound and it's a straight copy
+```
+
+### Getters/setters (8 and below)
+
+In IE8 `Object.defineProperty` can only be used on DOM objects. This is
+unfortunate as it's required to set getters and setters. Due to this if
+you plan on supporting IE8 or below then the user of getters and setters
+isn't recommended.
+
+**Reference**: [MDN](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty#Internet_Explorer_8_specific_notes).

doc/compare.md

@@ -0,0 +1,143 @@
+---
+layout: docs
+title: Compare
+description: Differences between 6to5 and other ES6 transpilers.
+permalink: /docs/compare/
+redirect_from: /differences.html
+---
+
+## Differences
+
+### Readable code
+
+The fundamental concept behind 6to5 is that the generated code must be close as
+possible to the original, retaining all the same formatting and readability.
+
+Many other transpilers are just concerned with making the code work while 6to5
+is concerned with making sure it works **and** is readable at the same time.
+
+For example, given the following array comprehension:
+
+```js
+var seattlers = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }];
+```
+
+is generated to the following with 6to5:
+
+```js
+var seattlers = Array.from(customers).filter(function (c) {
+  return c.city == "Seattle";
+}).map(function (c) {
+  return {
+    name: c.name,
+    age: c.age
+  };
+});
+```
+
+The following is what Traceur generates:
+
+```js
+var seattlers = (function() {
+  var c;
+  var $__20 = 0,
+      $__21 = [];
+  for (var $__22 = customers[$traceurRuntime.toProperty(Symbol.iterator)](),
+      $__23; !($__23 = $__22.next()).done; ) {
+    c = $__23.value;
+    if (c.city == "Seattle")
+      $traceurRuntime.setProperty($__21, $__20++, {
+        name: c.name,
+        age: c.age
+      });
+  }
+  return $__21;
+}());
+```
+
+As you can tell, it's not very pretty. Instead of mapping directly to a runtime,
+like other transpilers, 6to5 maps directly to the equivalent ES5.
+
+Sometimes there are little inline functions that 6to5 needs. These are
+placed at the top of your file much like coffee-script does. If these
+bother you then you can use the [optional runtime](optional-runtime.md).
+We promise that these inline functions will never be significant and will
+always be used as little as possible.
+
+### Static analysis
+
+6to5 uses a lot of static analysis to simplify code as much as possible.
+Not many other transpilers do this, and those that do don't do it nearly
+as much as 6to5. This process is pretty intensive but it leads to higher
+quality code.
+
+### Spec compliancy
+
+6to5 prides itself on
+[spec compliancy](https://kangax.github.io/compat-table/es6/). We have
+excellent support for edgecases, something that many other transpilers
+suffer from, including Traceur. When you use 6to5 you can be confident
+that when you turn it off and use your code in a full ES6 environment
+**it'll just work**.
+
+## Comparison to other transpilers
+
+### Features
+
+|                              | 6to5 | Traceur | es6-transpiler | es6now | jstransform |
+| ---------------------------- | ---- | ------- | -------------- | ------ | ----------- |
+| Source maps                  | ✓    | ✓       | ✓              |        | ✓           |
+| No compiler global pollution | ✓    |         | ✓              |        | ✓           |
+| Optional runtime             | ✓    |         | ✓              |        | ✓           |
+| Browser compiler             | ✓    | ✓       |                |        |             |
+
+### Language Support
+
+|                              | 6to5 | Traceur | es6-transpiler | es6now | jstransform |
+| ---------------------------- | ---- | ------- | -------------- | ------ | ----------- |
+| Abstract references          | ✓    |         |                |        |             |
+| Array comprehension          | ✓    | ✓       | ✓              |        |             |
+| Arrow functions              | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Async functions              | ✓    | ✓       |                |        |             |
+| Async generator functions    | ✓    | ✓       |                |        |             |
+| Classes                      | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Computed property names      | ✓    | ✓       | ✓              | ✓      |             |
+| Constants                    | ✓    | ✓       | ✓              |        |             |
+| Default parameters           | ✓    | ✓       | ✓              | ✓      |             |
+| Destructuring                | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Exponentiation operator      | ✓    | ✓       |                |        |             |
+| Flow types                   | ✓    |         |                |        | ✓           |
+| For-of                       | ✓    | ✓       | ✓              | ✓      |             |
+| Generators                   | ✓    | ✓       |                |        |             |
+| Generator comprehension      | ✓    | ✓       |                |        |             |
+| JSX                          | ✓    |         |                |        |             |
+| Let scoping                  | ✓    | ✓       | ✓              |        |             |
+| Modules                      | ✓    | ✓       |                | ✓      |             |
+| Object rest/spread           | ✓    |         |                |        | ✓           |
+| Property method assignment   | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Property name shorthand      | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Rest parameters              | ✓    | ✓       | ✓              | ✓      | ✓           |
+| React                        | ✓    |         |                |        |             |
+| Spread                       | ✓    | ✓       | ✓              | ✓      |             |
+| Template literals            | ✓    | ✓       | ✓              | ✓      | ✓           |
+| Unicode regex                | ✓    | ✓       | ✓              |        |             |
+
+### [Traceur](https://github.com/google/traceur-compiler)
+
+Traceur requires quite a bulky runtime (~75KB) and produces quite verbose code.
+While this can be trimmed down by selectively building the runtime, it's an
+unnecessary step when a large runtime can be eliminated entirely.
+
+### [es6now](https://github.com/zenparsing/es6now)
+
+es6now doesn't output sourcemaps. This is cited as a positive as line-to-line
+mapping is the goal. This however obviously doesn't retain column mapping
+resulting in the output code not being very pleasant.
+
+### [es6-transpiler](https://github.com/termi/es6-transpiler)
+
+The es6-transpiler compiler requires shims to operate which pollutes the global
+scope resulting in possible collisions.
+
+es6-transpiler maps line-by-line, just like es6now, this results in the same
+issues such as lack of column information and unpleasant code output.

doc/differences.md

@@ -1,113 +0,0 @@
-# Differences
-
-## Philosophy
-
-The fundamental concept behind 6to5 is that the generated code must be close as
-possible to the original, retaining all the same formatting and readability.
-
-Many other transpilers are just concerned with making the code work while 6to5
-is concerned with making sure it works **and** is readable at the same time.
-
-For example, given the following array comprehension:
-
-```javascript
-var seattlers = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }];
-```
-
-is generated to the following with 6to5:
-
-```javascript
-var seattlers = customers.filter(function (c) {
-  return c.city == "Seattle";
-}).map(function (c) {
-  return {
-    name: c.name,
-    age: c.age
-  };
-});
-```
-
-The following is what Traceur generates:
-
-```javascript
-var seattlers = (function() {
-  var c;
-  var $__20 = 0,
-      $__21 = [];
-  for (var $__22 = customers[$traceurRuntime.toProperty(Symbol.iterator)](),
-      $__23; !($__23 = $__22.next()).done; ) {
-    c = $__23.value;
-    if (c.city == "Seattle")
-      $traceurRuntime.setProperty($__21, $__20++, {
-        name: c.name,
-        age: c.age
-      });
-  }
-  return $__21;
-}());
-```
-
-As you can tell, it's not very pretty, unreadable even. Instead of mapping
-directly to a runtime, like other transpilers, 6to5 maps directly to the
-equivalent ES5.
-
-I'm not saying 6to5 is for everyone or even suited for everything. Traceur is
-better suited if you'd like a full ES6 environment with polyfills and all.
-
-## Comparison to other transpilers
-
-### Features
-
-|                              | 6to5 | Traceur | es6-transpiler | esnext | es6now | jstransform |
-| ---------------------------- | ---- | ------- | -------------- | ------ | ------ | ----------- |
-| Source maps                  | ✓    | ✓       | ✓              | ✓      |        | ✓           |
-| No compiler global pollution | ✓    |         | ✓              | ✓      |        | ✓           |
-| Optional runtime             | ✓    |         | ✓              |        |        | ✓           |
-| Browser support              | ✓    | ✓       |                | ✓      |        |             |
-
-### Language Support
-
-|                              | 6to5  | Traceur | es6-transpiler | esnext | es6now | jstransform |
-| ---------------------------- | ----- | ------- | -------------- | ------ | ------ | ----------- |
-| Abstract references          | ✓     |         |                |        |        |             |
-| Array comprehension          | ✓     | ✓       | ✓              |        |        |             |
-| Arrow functions              | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Async functions              | ✓     | ✓       |                | ✓      |        |             |
-| Classes                      | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Computed property names      | ✓     | ✓       | ✓              | ✓      | ✓      |             |
-| Constants                    | ✓     | ✓       | ✓              |        |        |             |
-| Default parameters           | ✓     | ✓       | ✓              | ✓      | ✓      |             |
-| Destructuring                | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Exponentiation operator      | ✓     | ✓       |                |        |        |             |
-| For-of                       | ✓     | ✓       | ✓              | ✓      | ✓      |             |
-| Generators                   | ✓     | ✓       |                | ✓      |        |             |
-| Generator comprehension      | ✓     | ✓       |                |        |        |             |
-| Let scoping                  | ✓     | ✓       | ✓              |        |        |             |
-| Modules                      | ✓     | ✓       |                |        | ✓      |             |
-| Object rest/spread           | ✓     |         |                |        |        | ✓           |
-| Property method assignment   | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Property name shorthand      | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Rest parameters              | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Spread                       | ✓     | ✓       | ✓              | ✓      | ✓      |             |
-| Template literals            | ✓     | ✓       | ✓              | ✓      | ✓      | ✓           |
-| Unicode regex                | ✓     | ✓       | ✓              |        |        |             |
-
-### [Traceur](https://github.com/google/traceur-compiler)
-
-Traceur requires quite a bulky runtime (~75KB) and produces quite verbose code.
-While this can be trimmed down by selectively building the runtime, it's an
-unneccesary step when a large runtime can be eliminated entirely.
-
-### [es6now](https://github.com/zenparsing/es6now)
-
-es6now doesn't output sourcemaps. This is cited as a positive as line-to-line
-mapping is the goal. This however obviously doesn't retain column mapping
-resulting in the output code not being very pleasant.
-
-### [es6-transpiler](https://github.com/termi/es6-transpiler)
-
-The es6-transpiler compiler requires shims to operate which pollutes the global
-scope resulting in possible collisions.
-
-es6-transpiler maps line-by-line, just like es6now, this results in the same
-issues such as lack of column information and unpleasant code output.

doc/features.md

@@ -1,277 +0,0 @@
-# Features
-
-## Abstract references ([experimental](usage.md#experimental)) ([spec](https://github.com/zenparsing/es-abstract-refs))
-
-```javascript
-foo::bar;
-foo::bar = baz;
-delete foo::bar;
-```
-
-## Array comprehensions ([experimental](usage.md#experimental))
-
-```javascript
-var results = [for (c of customers) if (c.city == "Seattle") { name: c.name, age: c.age }]
-```
-
-## Arrow functions
-
-```javascript
-// Expression bodies
-var odds = evens.map(v => v + 1);
-var nums = evens.map((v, i) => v + i);
-
-// Statement bodies
-nums.forEach(v => {
-  if (v % 5 === 0)
-    fives.push(v);
-});
-
-// Lexical this
-var bob = {
-  _name: "Bob",
-  _friends: [],
-  printFriends() {
-    this._friends.forEach(f => {
-      console.log(this._name + " knows " + f);
-    });
-  }
-};
-```
-
-## Async functions ([experimental](usage.md#experimental)) ([spec](https://github.com/lukehoban/ecmascript-asyncawait))
-
-```javascript
-async function chainAnimationsAsync(elem, animations) {
-  for (var anim of animations) {
-    await anim(elem);
-  }
-}
-```
-
-## Classes
-
-```javascript
-class SkinnedMesh extends THREE.Mesh {
-  constructor(geometry, materials) {
-    super(geometry, materials);
-
-    this.idMatrix = SkinnedMesh.defaultMatrix();
-    this.bones = [];
-    this.boneMatrices = [];
-    //...
-  }
-
-  update(camera) {
-    //...
-    super.update();
-  }
-
-  static defaultMatrix() {
-    return new THREE.Matrix4();
-  }
-}
-```
-
-## Computed property names
-
-```javascript
-var foo = "foo";
-var bar = "bar";
-var obj = {
-  ["foo" + bar]: "heh",
-  ["bar" + foo]: "noo",
-  foo: "foo",
-  bar: "bar"
-};
-```
-
-## Constants
-
-```javascript
-const MULTIPLIER = 5;
-console.log(2 * MULTIPLIER);
-
-MULTIPLIER = 6; // error
-var MULTIPLIER; // error
-```
-
-## Default parameters
-
-```javascript
-function f(x, y = 12) {
-  // y is 12 if not passed (or passed as undefined)
-  return x + y;
-}
-f(3) == 15
-```
-
-## Destructuring
-
-```javascript
-// list matching
-var [a, , b] = [1,2,3];
-
-// object matching
-var { op: a, lhs: { op: b }, rhs: c } = getASTNode();
-
-// object matching shorthand
-// binds `op`, `lhs` and `rhs` in scope
-var { op, lhs, rhs } = getASTNode();
-
-// Can be used in parameter position
-function g({ name: x }) {
-  console.log(x);
-}
-g({ name: 5 });
-
-// Fail-soft destructuring
-var [a] = [];
-a === undefined;
-```
-
-## Exponentiation operator ([experimental](usage.md#experimental)) ([spec](https://github.com/rwaldron/exponentiation-operator))
-
-```javascript
-var a = 2;
-a **= 2;
-
-var squared = 2 ** 2;
-```
-
-## For-of
-
-```javascript
-for (var i of [1, 2, 3]) {
-  console.log(i * i);
-}
-```
-
-## Generators
-
-```javascript
-function* fibonacci() {
-  var pre = 0, cur = 1;
-  for (;;) {
-    var temp = pre;
-    pre = cur;
-    cur += temp;
-    yield cur;
-  }
-}
-
-for (var n of fibonacci()) {
-  // truncate the sequence at 1000
-  if (n > 1000) break;
-  console.log(n);
-}
-```
-
-## Generator comprehensions ([experimental](usage.md#experimental))
-
-```javascript
-var nums = [1, 2, 3, 4, 5, 6];
-var multiples = (for (i of nums) if (i % 2) i * i);
-assert.equal(multiples.next().value, 1);
-assert.equal(multiples.next().value, 9);
-assert.equal(multiples.next().value, 25);
-```
-
-## Let scoping
-
-```javascript
-for (let i in arr) {
-  let v = arr[i];
-}
-```
-
-## Modules
-
-```javascript
-import "foo";
-import foo from "foo";
-import * as foo from "foo";
-import {bar} from "foo";
-import {foo as bar} from "foo";
-
-export { test };
-export var test = 5;
-export function test() {}
-
-export default test;
-```
-
-## Numeric literals
-
-```javascript
-0b111110111 === 503; // true
-0o767 === 503; // true
-```
-
-## Object spread/rest ([experimental](usage.md#experimental)) ([spec](https://github.com/sebmarkbage/ecmascript-rest-spread))
-
-```javascript
-var n = { x, y, ...z };
-var { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 };
-```
-
-## Property method assignment
-
-```javascript
-var obj = {
-  foo() {
-    return "foobar";
-  },
-
-  get bar() {
-    return this._bar;
-  },
-
-  set bar(val) {
-    this._bar = val;
-  }
-};
-```
-
-## Property name shorthand
-
-```javascript
-function f(x, y) {
-  return { x, y };
-}
-```
-
-## Rest parameters
-
-```javascript
-function f(x, ...y) {
-  // y is an Array
-  return x * y.length;
-}
-f(3, "hello", true) == 6
-```
-
-## Spread
-
-```javascript
-function f(x, y, z) {
-  return x + y + z;
-}
-// Pass each elem of array as argument
-f(...[1,2,3]) == 6
-```
-
-## Template literals
-
-```javascript
-var x = 5;
-var y = 10;
-console.log(`${x} + ${y} = ${x + y}`); // "5 + 10 = 15"
-```
-## Unicode regex
-
-```javascript
-var string = 'foo💩bar';
-var match = string.match(/foo(.)bar/u);
-console.log(match[1]);
-```

doc/index.md

@@ -1,61 +0,0 @@
-**6to5** turns ES6+ code into vanilla ES5, so you can use next generation features **today.**
-
- - **Readable** - formatting is retained if possible so your generated code is as similar as possible.
- - **Extensible** - with a large range of [plugins](plugins.md) and **browser support**.
- - **Lossless** - **source map support** so you can debug your compiled code with ease.
- - **Compact** - maps directly to the equivalent ES5 with **no runtime**[\*](caveats.md).
-
-## Installation
-
-It's as easy as:
-
-    $ npm install -g 6to5
-
-## Usage
-
-Once you've installed 6to5, there are multiple paths you can take depending on
-how you want to use it.
-
-6to5 will simply compile your ES6+ script to ES5 if you pass it as an argument
-to the command-line tool `6to5`:
-
-```sh
-$ 6to5 script.js
-```
-
-If you have a file written using ES6+ and you just want to run it, `6to5-node`
-has you covered:
-
-```sh
-$ 6to5-node script.js
-```
-
-And it doesn't end here! To see all the ways you can use 6to5, check out the
-[Usage](http://6to5.github.io/usage.html) page.
-
-## [Features](features.md)
-
- - [Abstract references](features.md#abstract-references) ([experimental](usage.md#experimental))
- - [Array comprehension](features.md#array-comprehension) ([experimental](usage.md#experimental))
- - [Async functions](features.md#async-functions) ([experimental](usage.md#experimental))
- - [Arrow functions](features.md#arrow-functions)
- - [Classes](features.md#classes)
- - [Computed property names](features.md#computed-property-names)
- - [Constants](features.md#constants)
- - [Default parameters](features.md#default-parameters)
- - [Destructuring](features.md#destructuring)
- - [Exponentiation operator](features.md#exponentiation-operator) ([experimental](usage.md#experimental))
- - [For-of](features.md#for-of)
- - [Generators](features.md#generators)
- - [Generator comprehension](features.md#generator-comprehension) ([experimental](usage.md#experimental))
- - [Let scoping](features.md#let-scoping)
- - [Modules](features.md#modules)
- - [Numeric literals](features.md#numeric-literals)
- - [Object Rest/Spread](features.md#object-rest-spread) ([experimental](usage.md#experimental))
- - [Property method assignment](features.md#property-method-assignment)
- - [Property name shorthand](features.md#property-name-shorthand)
- - [React/JSX](react.md)
- - [Rest parameters](features.md#rest-parameters)
- - [Spread](features.md#spread)
- - [Template literals](features.md#template-literals)
- - [Unicode regex](features.md#unicode-regex)

doc/playground.md

@@ -1,68 +0,0 @@
-# Playground
-
-Playground is a proving ground for **possible** ES7 proposals.
-
-**NOTE: These features are in no way endorsed by Ecma International and are not a part of ES6. They might become a part of ECMAScript in the future.**
-
-## Usage
-
-    $ 6to5 --playground
-
-```javascript
-to5.transform("code", { playground: true });
-```
-
-**NOTE:** Enabling `playground` also enables [experimental support](usage.md#experimental).
-
-## Features
-
- * [Memoization operator](#memoization-operator)
- * [Method binding](#method-binding)
-
-### Memoization assignment operator
-
-```javascript
-var obj = {};
-obj.x ?= 2;
-obj.x; // 2
-
-obj = { x: 1 };
-obj.x ?= 2;
-obj.x; // 1
-
-obj = { x: undefined }
-obj.x ?= 2;
-obj.x; // undefined
-```
-
-```javascript
-var obj = {};
-obj.x ?= 2;
-```
-
-equivalent to:
-
-```javascript
-var obj = {};
-if (!Object.prototype.hasOwnProperty.call(obj, "x")) obj.x = 2;
-```
-
-### Method binding
-
-```javascript
-var fn = obj:method;
-var fn = obj:method("foob");
-
-["foo", "bar"].map(:toUpperCase); // ["FOO", "BAR"]
-[1.1234, 23.53245, 3].map(:toFixed(2)); // ["1.12", "23.53", "3.00"]
-```
-
-equivalent to:
-
-```javascript
-var fn = obj.method.bind(obj);
-var fn = obj.method.bind(obj, "foob");
-
-["foo", "bar"].map(function (val) { return val.toUpperCase(); });
-[1.1234, 23.53245, 3].map(function (val) { return val.toFixed(2); });
-```

doc/plugins.md

@@ -1,18 +0,0 @@
-# Plugins
-
- - [Broccoli](https://github.com/very-geek/broccoli-6to5-transpiler)
- - [Browserify](https://github.com/6to5/6to5-browserify)
- - [Brunch](https://github.com/es128/6to5-brunch)
- - [Duo](https://github.com/bdo-labs/duo6to5)
- - [Connect](https://github.com/6to5/6to5-connect)
- - [Gobble](https://github.com/gobblejs/gobble-6to5)
- - [Gulp](https://github.com/sindresorhus/gulp-6to5)
- - [Grunt](https://github.com/sindresorhus/grunt-6to5)
- - [Isparta](https://github.com/douglasduteil/isparta) - Code coverage with `karma` and `instanbul` using 6to5
- - [Jade](https://github.com/Apoxx/jade-6to5)
- - [Jest](https://github.com/6to5/6to5-jest)
- - [JSXHint](https://github.com/STRML/JSXHint) - A wrapper around JSHint to allow linting of JSX files
- - [Karma](https://github.com/shuhei/karma-6to5-preprocessor)
- - [Mocha](https://github.com/6to5/6to5-mocha)
- - [Rails](https://github.com/josh/sprockets-es6) or via [browserify-rails](https://github.com/6to5/6to5-rails)
- - [webpack](https://github.com/Couto/6to5-loader)

doc/polyfill.md

@@ -1,27 +0,0 @@
-# Polyfill
-
-6to5 includes a polyfill that includes the
-[regenerator runtime](https://github.com/facebook/regenerator/blob/master/runtime.js) and the
-[es6-shim](https://github.com/paulmillr/es6-shim) and
-[es6-symbol](https://github.com/medikoo/es6-symbol) polyfills.
-
-This will emulate a full ES6 environment. This polyfill is automatically loaded
-when using [6to5-node](usage.md#node).
-
-## Usage
-
-### Node
-
-You need to include the polyfill require at the top the **entry point** to your
-application.
-
-```javascript
-require("6to5/polyfill");
-```
-
-### Browser
-
-Available from the `browser-polyfill.js` file within the 6to5 directory of an
-npm release. This needs to be included **before** all your compiled 6to5 code.
-You can either prepend it to your compiled code or include it in a `<script>`
-before it.

doc/react.md

@@ -1,17 +0,0 @@
-# React/JSX
-
-6to5 has built-in support for React v0.12. Tags are automatically transformed to
-their equivalent `React.createElement(...)` and `displayName` is automatically
-inferred and added to all `React.createClass` calls.
-
-## Blacklist
-
-To disable this behaviour add `react` to your blacklist:
-
-```javascript
-to5.transform("code", { blacklist: ["react"] });
-```
-
-```sh
-$ 6to5 --blacklist react
-```

doc/setup.md

@@ -0,0 +1,708 @@
+---
+layout: docs
+title: Setup
+description: Guides on how to setup 6to5 in whatever environment you might be working in.
+permalink: /docs/setup/
+redirect_from: /plugins.html
+---
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Find your guide</h4>
+  <p>
+    It doesn't matter if you're using Node.js or Rails, Gulp or Grunt, there's likely a guide on
+    this page to help guide you. Go ahead and <span class="label label-info">&#8984; + F</span>
+    whatever you're looking for. If it doesn't happen to be on this page you might want to stop by
+    our <a href="https://gitter.im/6to5/6to5">support chat</a>.
+  </p>
+</blockquote>
+
+## Node.js
+
+### CLI
+
+**Install**
+
+```sh
+$ npm install --global 6to5
+```
+
+**Usage**
+
+```sh
+$ 6to5 script.js
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    For full documentation on the 6to5 CLI see the
+    <a href="/docs/usage/cli/">usage docs</a>.
+  </p>
+</blockquote>
+
+### Require Hook
+
+**Install**
+
+```sh
+$ npm install 6to5
+```
+
+**Usage**
+
+All subsequent files required by node with the extensions `.es6` and `.js` will
+be transformed by 6to5. The polyfill specified in [Polyfill](polyfill.md) is
+also required.
+
+```javascript
+require('6to5/register');
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    For full documentation on the 6to5 require hook see the
+    <a href="/docs/usage/require/">usage docs</a>.
+  </p>
+</blockquote>
+
+## Rails
+
+### Sprockets
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>sprockets-es6</strong>'s
+    <a href="https://github.com/josh/sprockets-es6">repo</a> for more info. If
+    you find any bugs please
+    <a href="https://github.com/josh/sprockets-es6/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ gem install sprockets-es6
+```
+
+**Usage**
+
+```rb
+# Gemfile
+gem 'sprockets'
+gem 'sprockets-es6'
+```
+
+```rb
+require 'sprockets/es6'
+```
+
+## Build Systems
+
+### Brocolli
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>broccoli-6to5-transpiler</strong>'s
+    <a href="https://github.com/6to5/broccoli-6to5-transpiler">repo</a> for more
+    info. If you find any bugs please
+    <a href="https://github.com/6to5/broccoli-6to5-transpiler/issues">report
+    them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev broccoli-6to5-transpiler
+```
+
+**Usage**
+
+```js
+var to5Transpiler = require('broccoli-6to5-transpiler');
+var scriptTree = to5Transpiler(inputTree, options);
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Source maps</h4>
+  <p>
+    Currently this plugin only support inline source maps. If you need separate
+    source map feature, we welcome you to submit a pull request.
+  </p>
+</blockquote>
+
+### Browserify
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5ify</strong>'s
+    <a href="https://github.com/6to5/6to5ify">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/6to5ify/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev 6to5ify
+```
+
+**Usage via CLI**
+
+```sh
+$ browserify script.js -t 6to5ify --outfile bundle.js
+```
+
+**Usage via Node.js**
+
+```js
+browserify({ debug: true })
+  .transform(to5ify);
+```
+
+Or a more complete example:
+
+```js
+var fs = require('fs');
+var browserify = require('browserify');
+var to5ify = require('6to5ify');
+
+browserify({ debug: true })
+  .transform(to5ify)
+  .require('./script.js', { entry: true })
+  .bundle()
+  .on('error', function (err) { console.log('Error: ' + err.message); })
+  .pipe(fs.createWriteStream("bundle.js"));
+```
+**Passing Options**
+
+```sh
+$ browserify -d -e script.js -t [ 6to5ify --blacklist generators ]
+```
+
+```js
+browserify().transform(to5ify.configure({
+  blacklist: ['generators']
+}))
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>More info</h4>
+  <p>
+    For more information see the
+    <a href="https://github.com/6to5/6to5ify">6to5ify README</a>
+  </p>
+</blockquote>
+
+### Brunch
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5-brunch</strong>'s
+    <a href="https://github.com/6to5/6to5-brunch">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/6to5-brunch/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev 6to5-brunch
+```
+
+**Configuring**
+
+Set 6to5 options in your brunch config (such as `brunch-config.coffee`) except
+for `filename` and `sourceMap` which are handled internally.
+
+```coffee
+plugins:
+  ES6to5:
+    whitelist: ['arrowFunctions']
+    format:
+      semicolons: false
+```
+
+### Duo
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>duo-6to5</strong>'s
+    <a href="https://github.com/6to5/duo-6to5">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/duo-6to5/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev duo-6to5
+```
+
+**Usage via CLI**
+
+```sh
+$ duo --use duo-6to5
+```
+
+**Usage via Node.js**
+
+```js
+Duo(root)
+  .entry(entry)
+  .use(to5)
+  .run(fn);
+```
+
+### Gobble
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>gobble-6to5</strong>'s
+    <a href="https://github.com/6to5/gobble-6to5">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/gobble-6to5/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev gobble-6to5
+```
+
+**Usage**
+
+The `options` argument, if specified, is passed to 6to5.
+
+```
+var gobble = require('gobble');
+module.exports = gobble('src').transform('6to5', options);
+```
+
+**Source maps**
+
+Sourcemaps are created by default (all the relevant information is filled in by
+Gobble, you don't need to specify `sourceMapName` options etc). If you don't
+want that, pass `sourceMap: false`.
+
+### Grunt
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>grunt-6to5</strong>'s
+    <a href="https://github.com/6to5/grunt-6to5">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/grunt-6to5/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev grunt-6to5
+```
+
+**Usage**
+
+```js
+require('load-grunt-tasks')(grunt); // npm install --save-dev load-grunt-tasks
+
+grunt.initConfig({
+  '6to5': {
+    options: {
+      sourceMap: true
+    },
+    dist: {
+      files: {
+        'dist/app.js': 'src/app.js'
+      }
+    }
+  }
+});
+
+grunt.registerTask('default', ['6to5']);
+```
+
+### Gulp
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>gulp-6to5</strong>'s
+    <a href="https://github.com/6to5/gulp-6to5">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/gulp-6to5/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev gulp-6to5
+```
+
+**Usage**
+
+```js
+var gulp = require('gulp');
+var to5 = require('gulp-6to5');
+
+gulp.task('default', function () {
+  return gulp.src('src/app.js')
+    .pipe(to5())
+    .pipe(gulp.dest('dist'));
+});
+```
+
+**Source maps**
+
+Use [gulp-sourcemaps](https://github.com/floridoo/gulp-sourcemaps) like this:
+
+```js
+var gulp = require('gulp');
+var sourcemaps = require('gulp-sourcemaps');
+var to5 = require('gulp-6to5');
+var concat = require('gulp-concat');
+
+gulp.task('default', function () {
+  return gulp.src('src/**/*.js')
+    .pipe(sourcemaps.init())
+    .pipe(to5())
+    .pipe(concat('all.js'))
+    .pipe(sourcemaps.write('.'))
+    .pipe(gulp.dest('dist'));
+});
+```
+
+### Webpack
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5-loader</strong>'s
+    <a href="https://github.com/6to5/6to5-loader">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/6to5-loader/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev 6to5-loader
+```
+
+**Usage via loader**
+
+```js
+import Animal from '6to5!./Animal.js';
+
+class Person extends Animal {
+  constructor(arg='default') {
+    this.eat = 'Happy Meal';
+  }
+}
+
+export default Person;
+```
+```js
+var Person = require('6to5!./Person.js').default;
+new Person();
+```
+
+**Usage via config**
+
+```js
+module: {
+  loaders: [
+    { test: /\.js$/, exclude: /node_modules/, loader: '6to5-loader'}
+  ]
+}
+```
+
+and then import normally:
+
+```js
+import Person from './Person.js';
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Troubleshooting</h4>
+  <p>
+    For additional information on how to troubleshoot **6to5-loader** please
+    see the
+    <a href="https://github.com/6to5/6to5-loader#troubleshooting">README</a>.
+  </p>
+</blockquote>
+
+## Misc
+
+### Connect
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5-connect</strong>'s
+    <a href="https://github.com/6to5/6to5-connect">repo</a> for more info. If
+    you find any bugs please
+    <a href="https://github.com/6to5/6to5-connect/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```js
+$ npm install 6to5-connect
+```
+
+**Usage**
+
+```js
+var to5Middleware = require('6to5-connect');
+
+app.use(to5Middleware({
+  options: {
+    // options to use when transforming files
+  },
+  src: 'assets',
+  dest: 'cache'
+}));
+
+app.use(connect.static('cache'));
+```
+
+### Jade
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>jade-6to5</strong>'s
+    <a href="https://github.com/6to5/jade-6to5">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/jade-6to5/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```js
+$ npm install jade-6to5
+```
+
+**Usage**
+
+```js
+var jade = require('jade');
+var to5 = require('jade-6to5');
+
+jade.filters.to5 = to5({});
+```
+
+OR
+
+```js
+var jade = require('jade');
+var to5 = require('jade-6to5');
+
+jade = to5({}, jade);
+```
+
+Now you can use ES6 in your jade templates as following.
+
+```jade
+script
+  :to5
+    console.log('Hello World !!!');
+    class Person {
+      constructor(name) {
+        this.name = name;
+      }
+      sayName(){
+        console.log(`Hello, my name is ${this.name}`);
+      }
+    }
+    var person = new Person('Apoxx');
+    person.sayName();
+```
+
+### Jest
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5-jest</strong>'s
+    <a href="https://github.com/6to5/6to5-jest">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/6to5-jest/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev 6to5-jest
+```
+
+**Usage**
+
+In your `package.json` file please make the following changes:
+
+```
+{
+  "dependencies": {
+    "6to5-jest": "*",
+    "jest": "*"
+  },
+  "scripts": {
+    "test": "jest"
+  },
+  "jest": {
+    "scriptPreprocessor": "<rootDir>/node_modules/6to5-jest",
+    "testFileExtensions": ["es6", "js"],
+    "moduleFileExtensions": ["js", "json", "es6"]
+  }
+}
+```
+
+### Karma
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>karma-6to5-preprocessor</strong>'s
+    <a href="https://github.com/6to5/karma-6to5-preprocessor">repo</a> for more
+    info. If you find any bugs please
+    <a href="https://github.com/6to5/karma-6to5-preprocessor/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```js
+npm install --save-dev karma-6to5-preprocessor
+```
+
+**Usage**
+
+See 6to5 options for more details.
+
+Given `options` properties are passed to 6to5 with no change except:
+
+- `filename`
+- `sourceMapName`
+- `sourceFileName`
+
+Because they should differ from file to file, corresponding configuration
+functions are available.
+
+For example, inline sourcemap configuration would look like the following.
+
+```js
+module.exports = function(config) {
+  config.set({
+    files: [
+      'src/**/*.js',
+      'test/**/*.js'
+    ],
+    preprocessors: {
+      'src/**/*.js': ['6to5'],
+      'test/**/*.js': ['6to5']
+    },
+    '6to5Preprocessor': {
+      options: {
+        sourceMap: 'inline'
+      },
+      filename: function(file) {
+        return file.originalPath.replace(/\.js$/, '.es5.js');
+      },
+      sourceFileName: function(file) {
+        return file.originalPath;
+      }
+    }
+  });
+};
+```
+
+### Mocha
+
+<blockquote class="to5-callout to5-callout-info">
+  <p>
+    See <strong>6to5-mocha</strong>'s
+    <a href="https://github.com/6to5/6to5-mocha">repo</a> for more info. If you
+    find any bugs please
+    <a href="https://github.com/6to5/6to5-mocha/issues">report them</a>.
+  </p>
+  <p>
+    <em>Issues with the output should be reported on the 6to5
+    <a href="https://github.com/6to5/6to5/issues">issue tracker</a></em>.
+  </p>
+</blockquote>
+
+**Install**
+
+```sh
+$ npm install --save-dev 6to5
+```
+
+**Usage**
+
+```js
+{
+  "scripts": {
+    "test": "mocha --require 6to5/register"
+  },
+  "devDependencies": {
+    "6to5": "*",
+    "mocha": "*"
+  }
+}
+```

doc/tour.md

@@ -0,0 +1,771 @@
+---
+layout: docs
+title: Tour
+description: A detailed overview of ECMAScript 6 features.
+permalink: /docs/tour/
+redirect_from: /features.html
+---
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>es6features</h4>
+  <p>
+    This document is taken from Luke Hoban's excellent
+    <a href="http://git.io/es6features">es6features</a> repo. Go give it a star
+    on GitHub!
+  </p>
+</blockquote>
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>REPL</h4>
+  <p>
+    Be sure to try these features out in the online
+    <a href="repl.html">REPL</a>.
+  </p>
+</blockquote>
+
+## Introduction
+
+> ECMAScript 6 is the upcoming version of the ECMAScript standard.  This
+standard is targeting ratification in June 2015.  ES6 is a significant update to
+the language, and the first update to the language since ES5 was standardized in
+2009. Implementation of these features in major JavaScript engines is
+[underway now](http://kangax.github.io/es5-compat-table/es6/).
+
+See the [draft ES6 standard](https://people.mozilla.org/~jorendorff/es6-draft.html)
+for full specification of the ECMAScript 6 language.
+
+## ECMAScript 6 Features
+
+### Arrows
+
+Arrows are a function shorthand using the `=>` syntax.  They are syntactically
+similar to the related feature in C#, Java 8 and CoffeeScript.  They support
+both expression and statement bodies.  Unlike functions, arrows share the same
+lexical `this` as their surrounding code.
+
+```js
+// Expression bodies
+var odds = evens.map(v => v + 1);
+var nums = evens.map((v, i) => v + i);
+
+// Statement bodies
+nums.forEach(v => {
+  if (v % 5 === 0)
+    fives.push(v);
+});
+
+// Lexical this
+var bob = {
+  _name: "Bob",
+  _friends: [],
+  printFriends() {
+    this._friends.forEach(f =>
+      console.log(this._name + " knows " + f));
+  }
+}
+```
+
+### Classes
+
+ES6 classes are a simple sugar over the prototype-based OO pattern.  Having a
+single convenient declarative form makes class patterns easier to use, and
+encourages interoperability.  Classes support prototype-based inheritance, super
+calls, instance and static methods and constructors.
+
+```js
+class SkinnedMesh extends THREE.Mesh {
+  constructor(geometry, materials) {
+    super(geometry, materials);
+
+    this.idMatrix = SkinnedMesh.defaultMatrix();
+    this.bones = [];
+    this.boneMatrices = [];
+    //...
+  }
+  update(camera) {
+    //...
+    super.update();
+  }
+  static defaultMatrix() {
+    return new THREE.Matrix4();
+  }
+}
+```
+
+### Enhanced Object Literals
+
+Object literals are extended to support setting the prototype at construction,
+shorthand for `foo: foo` assignments, defining methods and making super calls.
+Together, these also bring object literals and class declarations closer
+together, and let object-based design benefit from some of the same
+conveniences.
+
+```js
+var obj = {
+    // __proto__
+    __proto__: theProtoObj,
+    // Shorthand for ‘handler: handler’
+    handler,
+    // Methods
+    toString() {
+     // Super calls
+     return "d " + super.toString();
+    },
+    // Computed (dynamic) property names
+    [ 'prop_' + (() => 42)() ]: 42
+};
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <p>
+    <code>__proto__</code> support comes from the JavaScript engine running
+    your program. Although most support the now standard property,
+    <a href="http://kangax.github.io/compat-table/es6/#__proto___in_object_literals">some do not</a>.
+  </p>
+</blockquote>
+
+### Template Strings
+
+Template strings provide syntactic sugar for constructing strings. This is
+similar to string interpolation features in Perl, Python and more. Optionally, a
+tag can be added to allow the string construction to be customized, avoiding
+injection attacks or constructing higher level data structures from string
+contents.
+
+```js
+// Basic literal string creation
+`In JavaScript '\n' is a line-feed.`
+
+// Multiline strings
+`In JavaScript this is
+ not legal.`
+
+// Construct a DOM query
+var name = "Bob", time = "today";
+`Hello ${name}, how are you ${time}?`
+
+// Construct an HTTP request prefix is used to interpret the replacements and construction
+GET`http://foo.org/bar?a=${a}&b=${b}
+    Content-Type: application/json
+    X-Credentials: ${credentials}
+    { "foo": ${foo},
+      "bar": ${bar}}`(myOnReadyStateChangeHandler);
+```
+
+### Destructuring
+
+Destructuring allows binding using pattern matching, with support for matching
+arrays and objects.  Destructuring is fail-soft, similar to standard object
+lookup `foo["bar"]`, producing `undefined` values when not found.
+
+```js
+// list matching
+var [a, , b] = [1,2,3];
+
+// object matching
+var { op: a, lhs: { op: b }, rhs: c }
+       = getASTNode()
+
+// object matching shorthand
+// binds `op`, `lhs` and `rhs` in scope
+var {op, lhs, rhs} = getASTNode()
+
+// Can be used in parameter position
+function g({name: x}) {
+  console.log(x);
+}
+g({name: 5})
+
+// Fail-soft destructuring
+var [a] = [];
+a === undefined;
+
+// Fail-soft destructuring with defaults
+var [a = 1] = [];
+a === 1;
+```
+
+### Default + Rest + Spread
+
+Callee-evaluated default parameter values. Turn an array into consecutive
+arguments in a function call. Bind trailing parameters to an array. Rest
+replaces the need for `arguments` and addresses common cases more directly.
+
+```js
+function f(x, y=12) {
+  // y is 12 if not passed (or passed as undefined)
+  return x + y;
+}
+f(3) == 15
+```
+```js
+function f(x, ...y) {
+  // y is an Array
+  return x * y.length;
+}
+f(3, "hello", true) == 6
+```
+```js
+function f(x, y, z) {
+  return x + y + z;
+}
+// Pass each elem of array as argument
+f(...[1,2,3]) == 6
+```
+
+### Let + Const
+
+Block-scoped binding constructs. `let` is the new `var`. `const` is
+single-assignment. Static restrictions prevent use before assignment.
+
+
+```js
+function f() {
+  {
+    let x;
+    {
+      // okay, block scoped name
+      const x = "sneaky";
+      // error, const
+      x = "foo";
+    }
+    // error, already declared in block
+    let x = "inner";
+  }
+}
+```
+
+### Iterators + For..Of
+
+Iterator objects enable custom iteration like CLR IEnumerable or Java
+Iteratable. Generalize `for..in` to custom iterator-based iteration with
+`for..of`. Don’t require realizing an array, enabling lazy design patterns like
+LINQ.
+
+```js
+let fibonacci = {
+  [Symbol.iterator]() {
+    let pre = 0, cur = 1;
+    return {
+      next() {
+        [pre, cur] = [cur, pre + cur];
+        return { done: false, value: cur }
+      }
+    }
+  }
+}
+
+for (var n of fibonacci) {
+  // truncate the sequence at 1000
+  if (n > 1000)
+    break;
+  print(n);
+}
+```
+
+Iteration is based on these duck-typed interfaces (using
+[TypeScript](http://typescriptlang.org) type syntax for exposition only):
+
+```ts
+interface IteratorResult {
+  done: boolean;
+  value: any;
+}
+interface Iterator {
+  next(): IteratorResult;
+}
+interface Iterable {
+  [Symbol.iterator](): Iterator
+}
+```
+
+### Generators
+
+Generators simplify iterator-authoring using `function*` and `yield`. A function
+declared as function* returns a Generator instance. Generators are subtypes of
+iterators which include additional `next` and `throw`. These enable values to
+flow back into the generator, so `yield` is an expression form which returns a
+value (or throws).
+
+Note: Can also be used to enable ‘await’-like async programming, see also ES7
+`await` proposal.
+
+```js
+var fibonacci = {
+  [Symbol.iterator]: function*() {
+    var pre = 0, cur = 1;
+    for (;;) {
+      var temp = pre;
+      pre = cur;
+      cur += temp;
+      yield cur;
+    }
+  }
+}
+
+for (var n of fibonacci) {
+  // truncate the sequence at 1000
+  if (n > 1000)
+    break;
+  print(n);
+}
+```
+
+The generator interface is (using [TypeScript](http://typescriptlang.org) type
+syntax for exposition only):
+
+```ts
+interface Generator extends Iterator {
+    next(value?: any): IteratorResult;
+    throw(exception: any);
+}
+```
+
+### Comprehensions
+
+Array and generator comprehensions provide simple declarative list processing
+similar as used in many functional programming patterns.
+
+```js
+// Array comprehensions
+var results = [
+  for(c of customers)
+    if (c.city == "Seattle")
+      { name: c.name, age: c.age }
+]
+
+// Generator comprehensions
+var results = (
+  for(c of customers)
+    if (c.city == "Seattle")
+      { name: c.name, age: c.age }
+)
+```
+
+### Unicode
+
+Non-breaking additions to support full Unicode, including new unicode literal
+form in strings and new RegExp `u` mode to handle code points, as well as new
+APIs to process strings at the 21bit code points level.  These additions support
+building global apps in JavaScript.
+
+```js
+// same as ES5.1
+"𠮷".length == 2
+
+// new RegExp behaviour, opt-in ‘u’
+"𠮷".match(/./u)[0].length == 2
+
+// new form
+"\u{20BB7}"=="𠮷" == "\uD842\uDFB7"
+
+// new String ops
+"𠮷".codePointAt(0) == 0x20BB7
+
+// for-of iterates code points
+for(var c of "𠮷") {
+  console.log(c);
+}
+```
+
+### Modules
+
+Language-level support for modules for component definition. Codifies patterns
+from popular JavaScript module loaders (AMD, CommonJS). Runtime behaviour
+defined by a host-defined default loader. Implicitly async model – no code
+executes until requested modules are available and processed.
+
+```js
+// lib/math.js
+export function sum(x, y) {
+  return x + y;
+}
+export var pi = 3.141593;
+```
+```js
+// app.js
+module math from "lib/math";
+alert("2π = " + math.sum(math.pi, math.pi));
+```
+```js
+// otherApp.js
+import {sum, pi} from "lib/math";
+alert("2π = " + sum(pi, pi));
+```
+
+Some additional features include `export default` and `export *`:
+
+```js
+// lib/mathplusplus.js
+export * from "lib/math";
+export var e = 2.71828182846;
+export default function(x) {
+    return Math.exp(x);
+}
+```
+```js
+// app.js
+module math from "lib/mathplusplus";
+import exp from "lib/mathplusplus";
+alert("2π = " + exp(math.pi, math.e));
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Module Formatters</h4>
+  <p>
+    6to5 can transpile ES6 Modules to several different formats including
+    Common.js, AMD, System, and UMD. You can even create your own. For more
+    details see the <a href="modules.html">modules docs</a>.
+  </p>
+</blockquote>
+
+### Module Loaders
+
+Module loaders support:
+- Dynamic loading
+- State isolation
+- Global namespace isolation
+- Compilation hooks
+- Nested virtualization
+
+The default module loader can be configured, and new loaders can be constructed
+to evaluated and load code in isolated or constrained contexts.
+
+```js
+// Dynamic loading – ‘System’ is default loader
+System.import('lib/math').then(function(m) {
+  alert("2π = " + m.sum(m.pi, m.pi));
+});
+
+// Create execution sandboxes – new Loaders
+var loader = new Loader({
+  global: fixup(window) // replace ‘console.log’
+});
+loader.eval("console.log('hello world!');");
+
+// Directly manipulate module cache
+System.get('jquery');
+System.set('jquery', Module({$: $})); // WARNING: not yet finalized
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Additional polyfill needed</h4>
+  <p>
+    Since 6to5 defaults to using common.js modules, it does not include the
+    polyfill for the module loader api. Get it
+    <a href="https://github.com/ModuleLoader/es6-module-loader">here</a>.
+  </p>
+</blockquote>
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Using Module Loader</h4>
+  <p>
+    In order to use this, you'll need to tell 6to5 to use the
+    <code>system</code> module formatter. Also be sure to check out
+    <a href="https://github.com/systemjs/systemjs">System.js</a>
+  </p>
+</blockquote>
+
+
+### Map + Set + WeakMap + WeakSet
+
+Efficient data structures for common algorithms.  WeakMaps provides leak-free
+object-key’d side tables.
+
+```js
+// Sets
+var s = new Set();
+s.add("hello").add("goodbye").add("hello");
+s.size === 2;
+s.has("hello") === true;
+
+// Maps
+var m = new Map();
+m.set("hello", 42);
+m.set(s, 34);
+m.get(s) == 34;
+
+// Weak Maps
+var wm = new WeakMap();
+wm.set(s, { extra: 42 });
+wm.size === undefined
+
+// Weak Sets
+var ws = new WeakSet();
+ws.add({ data: 42 });
+// Because the added object has no other references, it will not be held in the set
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Support via polyfill</h4>
+  <p>
+    In order to support Promises you must include the 6to5 Polyfill.
+  </p>
+</blockquote>
+
+### Proxies
+
+Proxies enable creation of objects with the full range of behaviors available to
+host objects.  Can be used for interception, object virtualization,
+logging/profiling, etc.
+
+```js
+// Proxying a normal object
+var target = {};
+var handler = {
+  get: function (receiver, name) {
+    return `Hello, ${name}!`;
+  }
+};
+
+var p = new Proxy(target, handler);
+p.world === 'Hello, world!';
+```
+
+```js
+// Proxying a function object
+var target = function () { return 'I am the target'; };
+var handler = {
+  apply: function (receiver, ...args) {
+    return 'I am the proxy';
+  }
+};
+
+var p = new Proxy(target, handler);
+p() === 'I am the proxy';
+```
+
+There are traps available for all of the runtime-level meta-operations:
+
+```js
+var handler =
+{
+  get:...,
+  set:...,
+  has:...,
+  deleteProperty:...,
+  apply:...,
+  construct:...,
+  getOwnPropertyDescriptor:...,
+  defineProperty:...,
+  getPrototypeOf:...,
+  setPrototypeOf:...,
+  enumerate:...,
+  ownKeys:...,
+  preventExtensions:...,
+  isExtensible:...
+}
+```
+
+<blockquote class="to5-callout to5-callout-danger">
+  <h4>Unsupported feature</h4>
+  <p>
+    Due to the limitations of ES5, Proxies cannot be transpiled or polyfilled.
+    See support from various
+    <a href="http://kangax.github.io/compat-table/es6/#Proxy">JavaScript
+    engines</a>.
+  </p>
+</blockquote>
+
+### Symbols
+
+Symbols enable access control for object state. Symbols allow properties to be
+keyed by either `string` (as in ES5) or `symbol`. Symbols are a new primitive
+type. Optional `name` parameter used in debugging - but is not part of identity.
+Symbols are unique (like gensym), but not private since they are exposed via
+reflection features like `Object.getOwnPropertySymbols`.
+
+```js
+(function() {
+
+  // module scoped symbol
+  var key = Symbol("key");
+
+  function MyClass(privateData) {
+    this[key] = privateData;
+  }
+
+  MyClass.prototype = {
+    doStuff: function() {
+      ... this[key] ...
+    }
+  };
+
+})();
+
+var c = new MyClass("hello")
+c["key"] === undefined
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Support via polyfill</h4>
+  <p>
+    In order to support Promises you must include the 6to5 Polyfill.
+  </p>
+</blockquote>
+
+### Subclassable Built-ins
+In ES6, built-ins like `Array`, `Date` and DOM `Element`s can be subclassed.
+
+Object construction for a function named `Ctor` now uses two-phases (both
+virtually dispatched):
+
+- Call `Ctor[@@create]` to allocate the object, installing any special behavior
+- Invoke constructor on new instance to initialize
+
+The known `@@create` symbol is available via `Symbol.create`. Built-ins now
+expose their `@@create` explicitly.
+
+```js
+// Pseudo-code of Array
+class Array {
+    constructor(...args) { /* ... */ }
+    static [Symbol.create]() {
+        // Install special [[DefineOwnProperty]]
+        // to magically update 'length'
+    }
+}
+
+// User code of Array subclass
+class MyArray extends Array {
+    constructor(...args) { super(...args); }
+}
+
+// Two-phase 'new':
+// 1) Call @@create to allocate object
+// 2) Invoke constructor on new instance
+var arr = new MyArray();
+arr[1] = 12;
+arr.length == 2
+```
+
+### Math + Number + String + Object APIs
+
+Many new library additions, including core Math libraries, Array conversion
+helpers, and Object.assign for copying.
+
+```js
+Number.EPSILON
+Number.isInteger(Infinity) // false
+Number.isNaN("NaN") // false
+
+Math.acosh(3) // 1.762747174039086
+Math.hypot(3, 4) // 5
+Math.imul(Math.pow(2, 32) - 1, Math.pow(2, 32) - 2) // 2
+
+"abcde".contains("cd") // true
+"abc".repeat(3) // "abcabcabc"
+
+Array.from(document.querySelectorAll('*')) // Returns a real Array
+Array.of(1, 2, 3) // Similar to new Array(...), but without special one-arg behavior
+[0, 0, 0].fill(7, 1) // [0,7,7]
+[1,2,3].findIndex(x => x == 2) // 1
+["a", "b", "c"].entries() // iterator [0, "a"], [1,"b"], [2,"c"]
+["a", "b", "c"].keys() // iterator 0, 1, 2
+["a", "b", "c"].values() // iterator "a", "b", "c"
+
+Object.assign(Point, { origin: new Point(0,0) })
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Limited support from polyfill</h4>
+  <p>
+    Most of these APIs are supported by the 6to5 Polyfill. However, certain
+    features are omitted for various reasons (ie.
+    <code>String.prototype.normalize</code> needs a lot of additional code to
+    support). You can find more polyfills
+    <a href="https://github.com/addyosmani/es6-tools#polyfills">here</a>.
+  </p>
+</blockquote>
+
+### Binary and Octal Literals
+Two new numeric literal forms are added for binary (`b`) and octal (`o`).
+
+```js
+0b111110111 === 503 // true
+0o767 === 503 // true
+```
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Only supports literal form</h4>
+  <p>
+    6to5 is only able to transform <code>0o767</code> and not
+    <code>Number('0o767')</code>.
+  </p>
+</blockquote>
+
+
+### Promises
+
+Promises are a library for asynchronous programming. Promises are a first class
+representation of a value that may be made available in the future. Promises are
+used in many existing JavaScript libraries.
+
+```js
+function timeout(duration = 0) {
+    return new Promise((resolve, reject) => {
+        setTimeout(resolve, duration);
+    })
+}
+
+var p = timeout(1000).then(() => {
+    return timeout(2000);
+}).then(() => {
+    throw new Error("hmm");
+}).catch(err => {
+    return Promise.all([timeout(100), timeout(200)]);
+})
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Support via polyfill</h4>
+  <p>
+    In order to support Promises you must include the 6to5 Polyfill.
+  </p>
+</blockquote>
+
+### Reflect API
+
+Full reflection API exposing the runtime-level meta-operations on objects. This
+is effectively the inverse of the Proxy API, and allows making calls
+corresponding to the same meta-operations as the proxy traps. Especially useful
+for implementing proxies.
+
+```js
+// No sample yet
+```
+
+<blockquote class="to5-callout to5-callout-danger">
+  <h4>Limited support from polyfill</h4>
+  <p>
+    Core.js only currently supports <code>Reflect.ownKeys</code>, if you would
+    like a much more complete Reflect API, include another polyfill such as
+    <a href="https://github.com/tvcutsem/harmony-reflect">Harmony Reflect</a>.
+  </p>
+</blockquote>
+
+### Tail Calls
+
+Calls in tail-position are guaranteed to not grow the stack unboundedly. Makes
+recursive algorithms safe in the face of unbounded inputs.
+
+```js
+function factorial(n, acc = 1) {
+    'use strict';
+    if (n <= 1) return acc;
+    return factorial(n - 1, n * acc);
+}
+
+// Stack overflow in most implementations today,
+// but safe on arbitrary inputs in eS6
+factorial(100000)
+```
+
+<blockquote class="to5-callout to5-callout-danger">
+  <h4>Unsupported feature</h4>
+  <p>
+    Due to high complexity of transpiling Tail Calls, 6to5 does not currently
+    have them implemented. See
+    <a href="https://github.com/6to5/6to5/issues/256">#256</a>.
+  </p>
+</blockquote>

doc/usage.md

@@ -1,216 +0,0 @@
-# Usage
-
-## CLI
-
-Compile the file `script.js` and output it to stdout.
-
-```sh
-$ 6to5 script.js
-```
-
-Compile the file `script.js` and output it to `script-compiled.js`.
-
-```sh
-$ 6to5 script.js --out-file script-compiled.js
-```
-
-Compile the file `script.js` and output it to `script-compiled.js` and save a
-source map to `script-compiled.js.map`.
-
-```sh
-$ 6to5 script.js --source-maps --out-file script-compiled.js
-```
-
-Compile the file `script.js` and output it to `script-compiled.js` with a source
-map embedded in a comment at the bottom.
-
-```sh
-$ 6to5 script.js --source-maps-inline --out-file script-compiled.js
-```
-
-Compile the entire `src` directory and output it to the `lib` directory.
-
-```sh
-$ 6to5 src --out-dir lib
-```
-
-Compile the entire `src` directory and output it to the one concatenated file.
-
-```sh
-$ 6to5 src --out-file script-compiled.js
-```
-
-Pipe a file in via stdin and output it to `script-compiled.js`
-
-```sh
-$ 6to5 --out-file script-compiled.js < script.js
-```
-
-### Node
-
-Launch a repl.
-
-```sh
-$ 6to5-node
-```
-
-Evaluate code.
-
-```sh
-$ 6to5-node -e "class Test { }"
-```
-
-Compile and run `test.js`.
-
-```sh
-$ 6to5-node test
-```
-
-## Node
-
-```javascript
-var to5 = require("6to5");
-```
-
-### to5.transform(code, [opts]);
-
-```javascript
-var result = to5.transform("code();", options);
-result.code;
-result.map;
-result.ast;
-```
-
-### to5.transformFileSync(filename, [opts])
-
-```javascript
-to5.transformFileSync("filename.js", options).code;
-```
-
-### to5.transformFile(filename, [opts], callback)
-
-```javascript
-to5.transformFile("filename.js", options, function (err, result) {
-  result.code;
-});
-```
-
-#### Options
-
-```javascript
-{
-  // Filename for use in errors etc.
-  // Default: "unknown"
-  filename: "filename",
-
-  // Filename relative to `sourceRoot`
-  // Default: `filename` option.
-  filenameRelative: "",
-
-  // List of transformers to EXCLUDE.
-  // Run `6to5 --help` to see a full list of transformers.
-  blacklist: [],
-
-  // List of transformers to ONLY use.
-  // Run `6to5 --help` to see a full list of transformers.
-  whitelist: [],
-
-  // Module formatter to use
-  // Run `6to5 --help` to see a full list of module formatters.
-  // Default: "common"
-  modules: "common",
-
-  // If truthy, adds a `map` property to returned output.
-  // If set to "inline", a comment with a sourceMappingURL directive is added to
-  // the bottom of the returned code.
-  // Default: false
-  sourceMap: true,
-
-  // Set `file` on returned source map.
-  // Default: `filenameRelative` option.
-  sourceMapName: "filename",
-
-  // Set `sources[0]` on returned source map.
-  // Default: `filenameRelative` option.
-  sourceFileName: "filename",
-
-  // The root from which all sources are relative
-  // Default: `moduleRoot` option.
-  sourceRoot: "assets/scripts",
-
-  // Optional prefix for the AMD module formatter that will be prepend to the
-  // filename on module definitions
-  // Default: `sourceRoot` option.
-  moduleRoot: "my-app",
-
-  // If truthy, insert an explicit id for each defined AMD module.
-  // By default, AMD modules are anonymous.
-  // Default: false
-  amdModuleIds: true,
-
-  // Optionally replace all 6to5 helper declarations with a referenece to this
-  // variable. If set to `true` then the default namespace is used "to5Runtime".
-  // Default: false
-  runtime: true,
-
-  // Output comments in generated output
-  // Default: true
-  comments: false,
-
-  // Enable support for experimental ES7 features
-  // Default: false
-  experimental: true
-}
-```
-
-### Require hook
-
-All subsequent files required by node with the extensions `.es6` and `.js` will
-be transformed by 6to5. The polyfill specified in [Polyfill](polyfill.md) is
-also required.
-
-```javascript
-require("6to5/register");
-```
-
-**NOTE:** By default all requires to `node_modules` will be ignored. You can
-override this by passing an ignore regex via:
-
-```javascript
-require("6to5/register")({
-  // This will override `node_modules` ignoring - you can alternatively pass
-  // a regex
-  ignore: false
-});
-```
-
-#### Options
-
-```javascript
-require("6to5/register")({
-  // Optional ignore regex - if any filenames **do** match this regex then they
-  // aren't compiled
-  ignore: /regex/,
-
-  // Optional only regex - if any filenames **don't** match this regex then they
-  // aren't compiled
-  only: /my_es6_folder/,
-
-  // See options above for usage
-  whitelist: [],
-  blacklist: [],
-
-  // This will remove the currently hooked extensions of .es6 and .js so you'll
-  // have to add them back if you want them to be used again.
-  extensions: [".js", ".es6"]
-});
-```
-
-## Experimental
-
-6to5 also has experimental support for ES7 proposals. You can enable this with
-the `experimental: true` option when using the [Node API](#node) or
-`--experimental` when using the [CLI](#cli).
-
-**WARNING:** These proposals are subject to change so use with
-**extreme caution**.

doc/usage/api.md

@@ -0,0 +1,59 @@
+---
+layout: docs
+title: API
+description: How to use the Node.js API.
+permalink: /docs/usage/api/
+---
+
+
+```javascript
+var to5 = require('6to5');
+```
+
+## to5.transform
+
+Transforms the passed in `code`.
+
+```
+to5.transform(code, [options])
+```
+
+**Example**
+
+```js
+var result = to5.transform('code();', options);
+result.code;
+result.map;
+result.ast;
+```
+
+## to5.transformFile
+
+Asynchronously transforms the entire contents of a file.
+
+```js
+to5.transformFile(filename, [options], callback)
+```
+
+**Example**
+
+```js
+to5.transformFile('filename.js', options, function (err, result) {
+  result.code;
+});
+```
+
+## to5.transformFileSync
+
+Synchronous version of `to5.transformFile`. Returns the transformed contents of
+the `filename`.
+
+```js
+to5.transformFileSync(filename, [options])
+```
+
+**Example**
+
+```js
+to5.transformFileSync('filename.js', options).code;
+```

doc/usage/browser.md

@@ -0,0 +1,59 @@
+---
+layout: docs
+title: Browser
+description: How to transpile in the browser.
+permalink: /docs/usage/browser/
+redirect_from: /browser.html
+---
+
+<p class="lead">
+  A browser version of 6to5 is available from `browser.js` inside the 6to5
+  directory in an npm release.
+</p>
+
+<blockquote class="to5-callout to5-callout-warning">
+  <h4>Not intended for serious use</h4>
+  <p>
+    Compiling in the browser has a fairly limited use case, so if you are
+    working on a production site you should be precompiling your scripts
+    server-side. See <a href="../setup/#build-systems">setup build systems</a>
+    for more information.
+  </p>
+</blockquote>
+
+## Script tags
+
+When the `browser.js` file is included all scripts with the type
+`text/ecmascript-6` and `text/6to5` are automatically compiled and ran.
+
+```html
+<script src="node_modules/6to5/browser.js"></script>
+<script type="text/6to5">
+class Test {
+  test() {
+    return 'test';
+  }
+}
+
+var test = new Test;
+test.test(); // "test"
+</script>
+```
+
+## API
+
+Programmatically transpile and execute strings of ES6 code.
+
+See [options](#options) for additional documentation.
+
+### `to5.transform(code, [opts])`
+
+```js
+to5.transform('class Test {}').code;
+```
+
+### `to5.run(code, [opts])`
+
+````js
+to5.run('class Test {}');
+````

doc/usage/cli.md

@@ -0,0 +1,99 @@
+---
+layout: docs
+title: CLI
+description: How to use the CLI tools.
+permalink: /docs/usage/cli/
+redirect_from: /usage.html
+---
+
+<p class="lead">
+  6to5 comes with a built-in CLI which can be used to compile files from the
+  command line.
+</p>
+
+## Install
+
+Using [npm](https://www.npmjs.com/) you can install 6to5 globally, making it
+available from the command line.
+
+```sh
+$ npm install --global 6to5
+```
+
+## 6to5
+
+#### Compile Files
+
+Compile the file `script.js` and **output to stdout**.
+
+```sh
+$ 6to5 script.js
+# output...
+```
+
+If you would like to **output to a file** you may use `--out-file` or `-o`.
+
+```sh
+$ 6to5 script.js --out-file script-compiled.js
+```
+
+### Compile with Source Maps
+
+If you would then like to add a **source map file** you can use
+`--source-maps` or `-s`. [Learn more about source maps](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/).
+
+```sh
+$ 6to5 script.js --out-file script-compiled.js --source-maps
+```
+
+If you would rather have **inline source maps**, you may use
+`--source-maps-inline` or `-t`.
+
+```sh
+$ 6to5 script.js --out-file script-compiled.js --source-maps-inline
+```
+
+### Compile Directories
+
+Compile the entire `src` directory and output it to the `lib` directory.
+
+```sh
+$ 6to5 src --out-dir lib
+```
+
+Compile the entire `src` directory and output it to the one concatenated file.
+
+```sh
+$ 6to5 src --out-file script-compiled.js
+```
+
+### Piping Files
+
+Pipe a file in via stdin and output it to `script-compiled.js`
+
+```sh
+$ 6to5 --out-file script-compiled.js < script.js
+```
+
+## 6to5-node
+
+6to5 comes with a second CLI which works exactly the same as Node.js's CLI, only
+it will compile ES6 code before running it.
+
+Launch a REPL (Read-Eval-Print-Loop).
+
+```sh
+$ 6to5-node
+```
+
+Evaluate code.
+
+```sh
+$ 6to5-node -e "class Test { }"
+```
+
+Compile and run `test.js`.
+
+```sh
+$ 6to5-node test
+```

doc/usage/experimental.md

@@ -0,0 +1,28 @@
+---
+layout: docs
+title: Experimental
+description: How to use experimental ES7 features.
+permalink: /docs/usage/experimental/
+redirect_from: /experimental.html
+---
+
+> 6to5 also has experimental support for ES7 proposals.
+
+<blockquote class="to5-callout to5-callout-danger">
+  <h4>Subject to change</h4>
+  <p>
+    These proposals are subject to change so <strong><em>use with extreme
+    caution</em></strong>. 6to5 may update without warning in order to track spec
+    changes. Please do not use them in production applications.
+  </p>
+</blockquote>
+
+#### Usage
+
+```js
+$ 6to5 --experimental
+```
+
+```js
+to5.transform('code', { experimental: true });
+```

doc/usage/jsx.md

@@ -0,0 +1,22 @@
+---
+layout: docs
+title: JSX
+description: How to use JSX.
+permalink: /docs/usage/jsx/
+---
+
+<p class="lead">
+  6to5 has built-in support for React v0.12. Tags are automatically transformed
+  to their equivalent <code>React.createElement(...)</code> and
+  <code>displayName</code> is automatically inferred and added to all
+  <code>React.createClass</code> calls.
+</p>
+
+## Blacklist
+
+To disable this behaviour add react to your blacklist:
+
+````js
+to5.transform("code", { blacklist: ["react"] });
+$ 6to5 --blacklist react
+```

doc/usage/modules.md

@@ -1,38 +1,44 @@
-# Modules
+---
+layout: docs
+title: Modules
+description: How to use module formatters.
+permalink: /docs/usage/modules/
+redirect_from: /modules.html
+---
+
+<p class="lead">
+  6to5 has the ability to transpile ES6 modules to the module system of your
+  choice. You can even easily create your own.
+</p>
 
 ## Usage
 
-### CLI
-
 ```sh
 $ 6to5 --modules common script.js
 ```
 
-### Node
-
-```javascript
-var to5 = require("6to5");
+```js
 to5.transform('import "foo";', { modules: "common" });
 ```
 
 ## Formats
 
- * [AMD](#amd)
- * [Common (Default)](#common-default)
- * [Common Interop](#common-interop)
- * [Ignore](#ignore)
- * [System](#system)
- * [UMD](#umd)
-
 ### Common (Default)
 
+**Usage**
+
 ```sh
 $ 6to5 --modules common
 ```
 
-**In**
+**Example**
+
+```js
+export default test;
+
+export {test};
+export var test = 5;
 
-```javascript
 import "foo";
 
 import foo from "foo";
@@ -40,106 +46,41 @@ import * as foo from "foo";
 
 import {bar} from "foo";
 import {foo as bar} from "foo";
-
-export {test};
-export var test = 5;
-
-export default test;
 ```
 
-**Out**
+```js
+"use strict";
 
-```javascript
-require("foo");
-
-var foo = require("foo").default;
-var foo = require("foo");
-
-var bar = require("foo").bar;
-var bar = require("foo").foo;
-
-exports.test = test;
-var test = 5; exports.test = test;
-
-exports.default = test;
-```
-
-### Common interop
-
-```sh
-$ 6to5 --modules commonInterop
-```
-
-**In**
-
-```javascript
-import "foo";
-
-import foo from "foo";
-import * as foo from "foo";
-
-import {bar} from "foo";
-import {foo as bar} from "foo";
-
-export {test};
-export var test = 5;
-
-export default test;
-```
-
-**Out**
-
-```javascript
 var _interopRequire = function (obj) {
   return obj && (obj["default"] || obj);
 };
 
-require("foo");
-
-var foo = _interopRequire(require("foo"));
-var foo = require("foo");
-
-var bar = require("foo").bar;
-var bar = require("foo").foo;
+exports = module.exports = test;
 
 exports.test = test;
 var test = exports.test = 5;
 
-exports["default"] = test;
-```
+require("foo");
 
-#### module.exports behaviour
+var foo = _interopRequire(require("foo"));
 
-If there exist no other non-default `export`s then `default exports` are
-exported as `module.exports` instead of `exports.default`.
+var foo = require("foo");
 
-**In**
-
-```javascript
-export default function foo() {
-
-}
-```
-
-**Out**
-
-```javascript
-module.exports = foo;
-
-function foo() {
-
-}
+var bar = require("foo").bar;
+var bar = require("foo").foo;
 ```
 
 ### AMD
 
+**Usage**
+
 ```sh
 $ 6to5 --modules amd
 ```
 
-**In**
+**Example**
 
-```javascript
+```js
 import foo from "foo";
 
 export function bar() {
@@ -147,13 +88,16 @@ export function bar() {
 }
 ```
 
-**Out**
-
-```javascript
+```js
 define(["exports", "foo"], function (exports, _foo) {
-  exports.bar = bar;
+  "use strict";
 
-  var foo = _foo.default;
+  var _interopRequire = function (obj) {
+    return obj && (obj["default"] || obj);
+  };
+
+  exports.bar = bar;
+  var foo = _interopRequire(_foo);
 
   function bar() {
     return foo("foobar");
@@ -161,81 +105,24 @@ define(["exports", "foo"], function (exports, _foo) {
 });
 ```
 
-You can optionally specify to include the module id (using the `--amd-module-id` argument):
+You can optionally specify to include the module id (using the `--amd-module-id`
+argument):
 
-```javascript
+```js
 define("filename", ["exports", "foo"], function (exports, _foo) {})
 ```
 
-### UMD
-
-```sh
-$ 6to5 --modules umd
-```
-
-**In**
-
-```javascript
-import foo from "foo";
-
-export function bar() {
-  return foo("foobar");
-}
-```
-
-**Out**
-
-```javascript
-(function (factory) {
-  if (typeof define === "function" && define.amd) {
-    define(["exports", "foo"], factory);
-  } else if (typeof exports !== "undefined") {
-    factory(exports, require("foo"));
-  }
-})(function (exports) {
-  exports.bar = bar;
-
-  var foo = _foo.default;
-
-  function bar() {
-    return foo("foobar");
-  }
-});
-```
-
-### Ignore
-
-```sh
-$ 6to5 --modules ignore
-```
-
-**In**
-
-```javascript
-import foo from "foo";
-
-export function bar() {
-  return foo("foobar");
-}
-```
-
-**Out**
-
-```javascript
-function bar() {
-  return foo("foobar");
-}
-```
-
 ### System
 
+**Usage**
+
 ```sh
 $ 6to5 --modules system
 ```
 
-**In**
+**Example**
 
-```javascript
+```js
 import foo from "foo";
 
 export function bar() {
@@ -243,9 +130,7 @@ export function bar() {
 }
 ```
 
-**Out**
-
-```javascript
+```js
 System.register("bar", ["foo"], function (_export) {
   "use strict";
 
@@ -266,29 +151,96 @@ System.register("bar", ["foo"], function (_export) {
 });
 ```
 
-## Custom
+### UMD
+
+**Usage**
+
+```sh
+$ 6to5 --modules umd
+```
+
+**Example**
+
+```js
+import foo from "foo";
+
+export function bar() {
+  return foo("foobar");
+}
+```
+
+```js
+(function (factory) {
+  if (typeof define === "function" && define.amd) {
+    define(["exports", "foo"], factory);
+  } else if (typeof exports !== "undefined") {
+    factory(exports, require("foo"));
+  }
+})(function (exports, _foo) {
+  "use strict";
+
+  var _interopRequire = function (obj) {
+    return obj && (obj["default"] || obj);
+  };
+
+  exports.bar = bar;
+  var foo = _interopRequire(_foo);
+
+  function bar() {
+    return foo("foobar");
+  }
+});
+```
+
+### Ignore
+
+**Usage**
+
+```sh
+$ 6to5 --modules ignore
+```
+
+**Example**
+
+```js
+import foo from "foo";
+
+export function bar() {
+  return foo("foobar");
+}
+```
+
+```js
+function bar() {
+  return foo("foobar");
+}
+```
+
+### Custom
 
 You can alternatively specify module names instead of one of the built-in types.
 
-```sh
+**Usage**
+
+```js
 $ 6to5 --modules custom-module-formatter
 ```
 
-**node_modules/custom-module-formatter/index.js**
+**Example**
 
-```javascript
+**`node_modules/custom-module-formatter/index.js`**
+
+```js
 module.exports = ModuleFormatter;
 
-function ModuleFormatter() {
-
-}
+function ModuleFormatter() {}
 
 ModuleFormatter.prototype.transform = function (ast) {
   // this is ran after all transformers have had their turn at modifying the ast
   // feel free to modify this however
 };
 
-ModuleFormatter.prototype.import = function (node, nodes) {
+ModuleFormatter.prototype.importDeclaration = function (node, nodes) {
   // node is an ImportDeclaration
 };
 
@@ -297,7 +249,7 @@ ModuleFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   // node is an ImportDeclaration
 };
 
-ModuleFormatter.prototype.export = function (node, nodes) {
+ModuleFormatter.prototype.exportDeclaration = function (node, nodes) {
   // node is an ExportDeclaration
 };
 

doc/usage/options.md

@@ -0,0 +1,35 @@
+---
+layout: docs
+title: Options
+description: Options for 6to5 transpiling.
+permalink: /docs/usage/options/
+---
+
+## Usage
+
+```js
+to5.transform(code, options);
+```
+
+```sh
+$ 6to5 --name=value
+```
+
+## Options
+
+| Option             | Default              | Description                     |
+| ------------------ | -------------------- | ------------------------------- |
+| `filename`         | `"unknown"`          | Filename for use in errors etc. |
+| `fileNameRelative` | `(filename)`         | Filename relative to `sourceRoot`. |
+| `blacklist`        | `[]`                 | Array of transformers to **exclude**. Run `6to5 --help` to see a full list of transformers. |
+| `whitelist`        | `[]`                 | Array of transformers to **only** use. Run `6to5 --help` to see a full list of transformers. |
+| `modules`          | `"common"`           | Which module formatter to use. Run `6to5 --help` to see a full list of module formatters. |
+| `sourceMap`        | `false`              | If truthy, adds a `map` property to returned output. If set to `"inline"`, a comment with a sourceMappingURL directive is added to the bottom of the returned code. |
+| `sourceMapName`    | `(filenameRelative)` | Set `file` on returned source map. |
+| `sourceFileName`   | `(filenameRelative)` | Set `sources[0]` on returned source map. |
+| `sourceRoot`       | `(moduleRoot)`       | The root from which all sources are relative. |
+| `moduleRoot`       | `(sourceRoot)`       | Optional prefix for the AMD module formatter that will be prepend to the filename on module definitions. |
+| `amdModuleIds`     | `false`              | If truthy, insert an explicit id for each defined AMD module. By default, AMD modules are anonymous. |
+| `runtime`          | `false`              | Optionally replace all 6to5 helper declarations with a referenece to this variable. If set to `true` then the default namespace is used `to5Runtime`. |
+| `comments`         | `true`               | Output comments in generated output. |
+| `experimental`     | `false`              | Enable support for experimental ES7 features. |

doc/usage/playground.md

@@ -0,0 +1,173 @@
+---
+layout: docs
+title: Playground
+description: How to use the playground.
+permalink: /docs/usage/playground/
+redirect_from: /playground.html
+---
+
+> Playground is a proving ground for language ideas.
+
+<blockquote class="to5-callout to5-callout-danger">
+  <h4>Unofficial</h4>
+  <p>
+    These features are in no way endorsed by Ecma International and are not a
+    part of any ECMAScript standard, nor are they necessarily on track to become
+    part of any standard. <strong><em>Use with extreme caution</em></strong>.
+  </p>
+</blockquote>
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Proposal Authors</h4>
+  <p>
+    If you are actively working on an
+    <a href="https://github.com/tc39/ecma262">ECMAScript proposal</a>, this is a
+    good place to get your ideas implemented with so that they may be tested
+    with all of the latest language and API features.
+  </p>
+  <p>
+    Please feel free to <a href="https://github.com/6to5/6to5/issues/new">open
+    an issue</a> on the 6to5 repository with your WIP spec, and we can discuss
+    getting it implemented. Be sure to include as much information as possible.
+  </p>
+</blockquote>
+
+## Usage
+
+```js
+$ 6to5 --playground
+```
+
+```js
+to5.transform('code', { playground: true });
+```
+
+<blockquote class="to5-callout to5-callout-info">
+  <h4>Enables experimental</h4>
+  <p>
+    Enabling playground also enables experimental support.
+  </p>
+</blockquote>
+
+## Features
+
+### Memoization assignment operator
+
+The memoization assignment operator allows you to lazily set an object property.
+It checks whether there's a property defined on the object and if there isn't
+then the right hand value is set.
+
+This means that `obj.x` in the following `var x = { x: undefined }; obj.x ?= 2;``
+will still be `undefined` because it's already been defined on the object.
+
+**Uses**
+
+```js
+var obj = {};
+obj.x ?= 2;
+obj.x; // 2
+
+obj = { x: 1 };
+obj.x ?= 2;
+obj.x; // 1
+
+obj = { x: undefined }
+obj.x ?= 2;
+obj.x; // undefined
+```
+
+**Example**
+
+```js
+var obj = {};
+obj.x ?= 2;
+```
+
+is equivalent to
+
+```js
+var obj = {};
+if (!Object.prototype.hasOwnProperty.call(obj, 'x')) obj.x = 2;
+```
+
+### Method binding
+
+```javascript
+var fn = obj#method;
+var fn = obj#method("foob");
+```
+
+is equivalent to
+
+```javascript
+var fn = obj.method.bind(obj);
+var fn = obj.method.bind(obj, "foob");
+```
+
+### Method binding function shorthand
+
+```javascript
+["foo", "bar"].map(#toUpperCase); // ["FOO", "BAR"]
+[1.1234, 23.53245, 3].map(#toFixed(2)); // ["1.12", "23.53", "3.00"]
+```
+
+equivalent to
+
+```javascript
+["foo", "bar"].map(function (val) { return val.toUpperCase(); });
+[1.1234, 23.53245, 3].map(function (val) { return val.toFixed(2); });
+```
+
+### Object getter memoization
+
+```js
+var foo = {
+  memo bar() {
+    return complex();
+  }
+};
+
+class Foo {
+  memo bar() {
+    return complex();
+  }
+}
+```
+
+is equivalent to
+
+```js
+var foo = {
+  get bar() {
+    return Object.defineProperty(this, "bar", {
+      value: complex(),
+      enumerable: true,
+      configurable: true,
+      writable: true
+    }).bar;
+  }
+};
+
+class Foo {
+  get bar() {
+    return Object.defineProperty(this, "bar", {
+      value: complex(),
+      enumerable: true,
+      configurable: true,
+      writable: true
+    }).bar;
+  }
+}
+```
+
+### This shorthand
+
+```js
+@foo
+```
+
+is equivalent to
+
+```
+this.foo
+```

doc/usage/polyfill.md

@@ -0,0 +1,56 @@
+---
+layout: docs
+title: Polyfill
+description: How to use the Polyfill.
+permalink: /docs/usage/polyfill/
+---
+
+<p class="lead">
+  6to5 includes a polyfill that includes a custom
+  <a href="https://github.com/facebook/regenerator/blob/master/runtime.js">regenerator runtime</a>
+  and <a href="https://github.com/zloirock/core-js">core.js</a>.
+</p>
+
+This will emulate a full ES6 environment. This polyfill is automatically loaded
+when using `6to5-node` and `6to5/register`.
+
+## Usage in Node/Browserify
+
+You need to include the polyfill require at the top the **entry point** to
+your application.
+
+```js
+require('6to5/polyfill');
+```
+
+Fortunately, this is automatically loaded when using:
+
+```js
+require('6to5/register');
+```
+
+## Usage in Browser
+
+Available from the `browser-polyfill.js` file within the 6to5 directory of an
+npm release. This needs to be included **before** all your compiled 6to5 code.
+You can either prepend it to your compiled code or include it in a `<script>`
+before it.
+
+**NOTE:** Do not `require` this via browserify etc, use `6to5/polyfill`.
+
+<blockquote class="to5-callout to5-callout-warning">
+<h4>Polyfills are not perfect</h4>
+<p>
+Due to limitations in various ES5 environments not every polyfill will work
+in every environment.
+</p>
+</blockquote>
+
+<blockquote class="to5-callout to5-callout-warning">
+<h4>Certain polyfills not included</h4>
+<p>
+Certain polyfills are too large/complex for their implemented features to
+justify including them for all builds. You may have to include additional
+polyfills for a subset of ES6 features.
+</p>
+</blockquote>

doc/usage/require.md

@@ -0,0 +1,55 @@
+---
+layout: docs
+title: Require Hook
+description: How to use the require hook.
+permalink: /docs/usage/require/
+---
+
+## Install
+
+```sh
+$ npm install 6to5
+```
+
+## Usage
+
+```js
+require('6to5/register');
+```
+
+All subsequent files required by node with the extensions `.es6`, `.es`, and
+`.js` will be transformed by 6to5. The polyfill specified in Polyfill is also
+required.
+
+**NOTE:** By default all requires to `node_modules` will be ignored. You can
+override this by passing an ignore regex via:
+
+```js
+require('6to5/register')({
+  // This will override `node_modules` ignoring - you can alternatively pass
+  // a regex
+  ignore: false
+});
+```
+
+## Register Options
+
+```javascript
+require('6to5/register')({
+  // Optional ignore regex - if any filenames **do** match this regex then they
+  // aren't compiled
+  ignore: /regex/,
+
+  // Optional only regex - if any filenames **don't** match this regex then they
+  // aren't compiled
+  only: /my_es6_folder/,
+
+  // See options above for usage
+  whitelist: [],
+  blacklist: [],
+
+  // This will remove the currently hooked extensions of .es6 and .js so you'll
+  // have to add them back if you want them to be used again.
+  extensions: ['.js', '.es6']
+});
+```

doc/usage/runtime.md

@@ -1,4 +1,11 @@
-# Optional runtime
+---
+layout: docs
+title: Optional Runtime
+description: How to use the optional runtime.
+permalink: /docs/usage/runtime/
+---
+
+## Details
 
 6to5 has a few helper functions that'll be placed at the top of the generated
 code if needed so it's not inlined multiple times throughout that file. This may
@@ -8,25 +15,17 @@ to the browser. gzip alleviates most of this concern but it's still not ideal.
 You can tell 6to5 to not place any declarations at the top of your files and
 instead just point them to a reference contained within the runtime.
 
-Simply use the following option if you're using the [Node API](usage.md#node):
+## Usage
 
-```javascript
-{
-  runtime: true
-}
-```
-
-or the following flag if you're using the [CLI](usage.md#cli):
-
-```ssh
+```js
 $ 6to5 --runtime
 ```
 
-Then just include the runtime before your generated code.
+```js
+to5.transform('code', { runtime: true });
+```
 
-## Getting the runtime
-
-You can get the runtime via either:
+### Getting the runtime
 
 ```sh
 $ 6to5-runtime
@@ -34,24 +33,24 @@ $ 6to5-runtime
 
 or
 
-```javascript
-require("6to5").runtime();
+```js
+require('6to5').runtime();
 ```
 
 or from an npm release in `runtime.js` from the 6to5 directory.
 
-## Customising namespace
+### Customising namespace
 
 You can also customise the runtime namespace by passing an optional namespace
 argument:
 
-```javascript
-require("6to5").runtime("myCustomNamespace");
-```
-
 ```sh
 $ 6to5-runtime myCustomNamespace
 ```
 
-See [Options - runtime](usage.md#options) for documentation on changing the
-reference in generated code.
+```js
+require("6to5").runtime('myCustomNamespace');
+```
+
+See [Options - runtime](../options) for documentation on changing the reference in
+generated code.

lib/6to5/browser.js

@@ -34,7 +34,7 @@ transform.load = function (url, callback, opts, hold) {
 
 var runScripts = function () {
   var scripts = [];
-  var types   = ["text/ecmascript-6", "text/6to5"];
+  var types   = ["text/ecmascript-6", "text/6to5", "module"];
   var index   = 0;
 
   var exec = function () {
@@ -60,8 +60,9 @@ var runScripts = function () {
     }
   };
 
-  var _scripts = global.document.getElementsByTagName("script");
-  for (var i in _scripts) {
+  var _scripts = global.document .getElementsByTagName("script");
+
+  for (var i = 0; i < _scripts.length; ++i) {
     var _script = _scripts[i];
     if (types.indexOf(_script.type) >= 0) scripts.push(_script);
   }

lib/6to5/file.js

@@ -10,21 +10,37 @@ var t         = require("./types");
 var _         = require("lodash");
 
 function File(opts) {
-  this.opts = File.normaliseOptions(opts);
-  this.uids = {};
-  this.ast  = {};
+  this.dynamicImports   = [];
+  this.dynamicImportIds = {};
+  this.opts             = File.normaliseOptions(opts);
+  this.transformers     = this.getTransformers();
+  this.uids             = {};
+  this.ast              = {};
 }
 
-File.declarations = [
-  "extends",
-  "class-props",
+File.helpers = [
+  "inherits",
+  "defaults",
+  "prototype-properties",
   "apply-constructor",
   "tagged-template-literal",
   "interop-require",
   "to-array",
-  "object-spread",
+  "sliced-to-array",
+  "object-without-properties",
   "has-own",
-  "slice"
+  "slice",
+  "bind",
+  "define-property",
+  "async-to-generator",
+  "interop-require-wildcard",
+  "typeof",
+  "exports-wildcard"
+];
+
+File.excludeHelpersFromRuntime = [
+  "async-to-generator",
+  "typeof"
 ];
 
 File.normaliseOptions = function (opts) {
@@ -34,14 +50,17 @@ File.normaliseOptions = function (opts) {
     experimental: false,
     playground:   false,
     whitespace:   true,
+    moduleIds:    opts.amdModuleIds || false,
     blacklist:    [],
     whitelist:    [],
     sourceMap:    false,
+    optional:     [],
     comments:     true,
     filename:     "unknown",
     modules:      "common",
     runtime:      false,
-    code:         true
+    code:         true,
+    ast:          true
   });
 
   // normalise windows path separators to unix
@@ -77,17 +96,46 @@ File.normaliseOptions = function (opts) {
 
   transform._ensureTransformerNames("blacklist", opts.blacklist);
   transform._ensureTransformerNames("whitelist", opts.whitelist);
+  transform._ensureTransformerNames("optional", opts.optional);
 
   return opts;
 };
 
-File.prototype.toArray = function (node) {
+File.prototype.getTransformers = function () {
+  var file = this;
+  var transformers = [];
+  var secondPassTransformers = [];
+
+  _.each(transform.transformers, function (transformer) {
+    if (transformer.canRun(file)) {
+      transformers.push(transformer);
+
+      if (transformer.secondPass) {
+        secondPassTransformers.push(transformer);
+      }
+
+      if (transformer.manipulateOptions) {
+        transformer.manipulateOptions(file.opts, file);
+      }
+    }
+  });
+
+  return transformers.concat(secondPassTransformers);
+};
+
+File.prototype.toArray = function (node, i) {
   if (t.isArrayExpression(node)) {
     return node;
   } else if (t.isIdentifier(node) && node.name === "arguments") {
-    return t.callExpression(t.memberExpression(this.addDeclaration("slice"), t.identifier("call")), [node]);
+    return t.callExpression(t.memberExpression(this.addHelper("slice"), t.identifier("call")), [node]);
   } else {
-    return t.callExpression(this.addDeclaration("to-array"), [node]);
+    var declarationName = "to-array";
+    var args = [node];
+    if (i) {
+      args.push(t.literal(i));
+      declarationName = "sliced-to-array";
+    }
+    return t.callExpression(this.addHelper(declarationName), args);
   }
 };
 
@@ -100,7 +148,7 @@ File.prototype.getModuleFormatter = function (type) {
   }
 
   if (!ModuleFormatter) {
-    throw new ReferenceError("unknown module formatter type " + type);
+    throw new ReferenceError("Unknown module formatter type " + JSON.stringify(type));
   }
 
   return new ModuleFormatter(this);
@@ -118,8 +166,24 @@ File.prototype.parseShebang = function (code) {
   return code;
 };
 
-File.prototype.addDeclaration = function (name) {
-  if (!_.contains(File.declarations, name)) {
+File.prototype.addImport = function (source, name) {
+  name = name || source;
+  var id = this.dynamicImportIds[name];
+
+  if (!id) {
+    id = this.dynamicImportIds[name] = this.generateUidIdentifier(name);
+
+    var specifiers = [t.importSpecifier(t.identifier("default"), id)];
+    var declar = t.importDeclaration(specifiers, t.literal(source));
+    declar._blockHoist = 3;
+    this.dynamicImports.push(declar);
+  }
+
+  return id;
+};
+
+File.prototype.addHelper = function (name) {
+  if (!_.contains(File.helpers, name)) {
     throw new ReferenceError("unknown declaration " + name);
   }
 
@@ -130,7 +194,7 @@ File.prototype.addDeclaration = function (name) {
 
   var ref;
   var runtimeNamespace = this.opts.runtime;
-  if (runtimeNamespace) {
+  if (runtimeNamespace && !_.contains(File.excludeHelpersFromRuntime, name)) {
     name = t.identifier(t.toIdentifier(name));
     return t.memberExpression(t.identifier(runtimeNamespace), name);
   } else {
@@ -155,14 +219,16 @@ File.prototype.errorWithNode = function (node, msg, Error) {
   return err;
 };
 
-File.prototype.parse = function (code) {
+File.prototype.addCode = function (code) {
   code = (code || "") + "";
+  this.code = code;
+  return this.parseShebang(code);
+};
 
+File.prototype.parse = function (code) {
   var self = this;
 
-  this.code = code;
-
-  code = this.parseShebang(code);
+  code = this.addCode(code);
 
   return util.parse(this.opts, code, function (tree) {
     self.transform(tree);
@@ -171,30 +237,43 @@ File.prototype.parse = function (code) {
 };
 
 File.prototype.transform = function (ast) {
+  var self = this;
+
   this.ast = ast;
   this.scope = new Scope(ast.program);
   this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
 
-  var self = this;
+  var astRun = function (key) {
+    _.each(self.transformers, function (transformer) {
+      transformer.astRun(self, key);
+    });
+  };
 
-  _.each(transform.transformers, function (transformer) {
+  astRun("enter");
+
+  _.each(this.transformers, function (transformer) {
     transformer.transform(self);
   });
+
+  astRun("exit");
 };
 
 File.prototype.generate = function () {
   var opts = this.opts;
   var ast  = this.ast;
 
-  if (!opts.code) {
-    return {
-      code: "",
-      map:  null,
-      ast:  ast
-    };
-  }
+  var result = {
+    code: "",
+    map: null,
+    ast: null
+  };
 
-  var result = generate(ast, opts, this.code);
+  if (opts.ast) result.ast = ast;
+  if (!opts.code) return result;
+
+  var _result = generate(ast, opts, this.code);
+  result.code = _result.code;
+  result.map  = _result.map;
 
   if (this.shebang) {
     // add back shebang
@@ -205,13 +284,11 @@ File.prototype.generate = function () {
     result.code += "\n" + util.sourceMapToComment(result.map);
   }
 
-  result.ast = result;
-
   return result;
 };
 
 File.prototype.generateUid = function (name, scope) {
-  name = t.toIdentifier(name);
+  name = t.toIdentifier(name).replace(/^_+/, "");
 
   scope = scope || this.scope;
 

lib/6to5/generation/buffer.js

@@ -35,7 +35,7 @@ Buffer.prototype.dedent = function () {
 };
 
 Buffer.prototype.semicolon = function () {
-  if (this.format.semicolons) this.push(";");
+  this.push(";");
 };
 
 Buffer.prototype.ensureSemicolon = function () {
@@ -66,9 +66,7 @@ Buffer.prototype.removeLast = function (cha) {
 };
 
 Buffer.prototype.newline = function (i, removeLast) {
-  if (!this.buf) return;
   if (this.format.compact) return;
-  if (this.endsWith("{\n")) return;
 
   if (_.isBoolean(i)) {
     removeLast = i;
@@ -76,6 +74,7 @@ Buffer.prototype.newline = function (i, removeLast) {
   }
 
   if (_.isNumber(i)) {
+    if (this.endsWith("{\n")) i--;
     if (this.endsWith(util.repeat(i, "\n"))) return;
 
     var self = this;
@@ -88,7 +87,10 @@ Buffer.prototype.newline = function (i, removeLast) {
   if (removeLast && this.isLast("\n")) this.removeLast("\n");
 
   this.removeLast(" ");
+
+  // remove whitespace if last character was a newline
   this.buf = this.buf.replace(/\n +$/, "\n");
+
   this._push("\n");
 };
 

lib/6to5/generation/generator.js

@@ -37,7 +37,6 @@ _.each(Buffer.prototype, function (fn, key) {
 CodeGenerator.normaliseOptions = function (opts) {
   return _.merge({
     parentheses: true,
-    semicolons: true,
     comments: opts.comments == null || opts.comments,
     compact: false,
     indent: {
@@ -58,6 +57,7 @@ CodeGenerator.generators = {
   methods:          require("./generators/methods"),
   modules:          require("./generators/modules"),
   types:            require("./generators/types"),
+  flow:             require("./generators/flow"),
   base:             require("./generators/base"),
   jsx:              require("./generators/jsx")
 };
@@ -71,6 +71,12 @@ CodeGenerator.prototype.generate = function () {
 
   this.print(ast);
 
+  var comments = [];
+  _.each(ast.comments, function (comment) {
+    if (!comment._displayed) comments.push(comment);
+  });
+  this._printComments(comments);
+
   return {
     map:  this.map.get(),
     code: this.buffer.get()
@@ -109,6 +115,7 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
   if (!node) return "";
 
   var self = this;
+
   opts = opts || {};
 
   var newline = function (leading) {
@@ -132,12 +139,21 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
       var needs = n.needsWhitespaceAfter;
       if (leading) needs = n.needsWhitespaceBefore;
       lines += needs(node, parent);
+
+      // generated nodes can't add starting file whitespace
+      if (!self.buffer.get()) lines = 0;
     }
 
     self.newline(lines);
   };
 
   if (this[node.type]) {
+    var needsNoLineTermParens = n.needsParensNoLineTerminator(node, parent);
+    var needsParens           = needsNoLineTermParens || n.needsParens(node, parent);
+
+    if (needsParens) this.push("(");
+    if (needsNoLineTermParens) this.indent();
+
     this.printLeadingComments(node, parent);
 
     newline(true);
@@ -145,13 +161,12 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
     if (opts.before) opts.before();
     this.map.mark(node, "start");
 
-    // only compute if this node needs parens if our parent has been changed
-    // since acorn would've wrapped us in a ParanthesizedExpression
-    var needsParens = parent !== node._parent && n.needsParens(node, parent);
-    if (needsParens) this.push("(");
-
     this[node.type](node, this.buildPrint(node), parent);
 
+    if (needsNoLineTermParens) {
+      this.newline();
+      this.dedent();
+    }
     if (needsParens) this.push(")");
 
     this.map.mark(node, "end");
@@ -161,7 +176,7 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
 
     this.printTrailingComments(node, parent);
   } else {
-    throw new ReferenceError("unknown node " + node.type);
+    throw new ReferenceError("unknown node of type " + JSON.stringify(node.type) + " with constructor " + JSON.stringify(node && node.constructor.name));
   }
 };
 
@@ -259,6 +274,21 @@ CodeGenerator.prototype._printComments = function (comments) {
   var self = this;
 
   _.each(comments, function (comment) {
+    var skip = false;
+
+    // find the original comment in the ast and set it as displayed
+    _.each(self.ast.comments, function (origComment) {
+      if (origComment.start === comment.start) {
+        // comment has already been output
+        if (origComment._displayed) skip = true;
+
+        origComment._displayed = true;
+        return false;
+      }
+    });
+
+    if (skip) return;
+
     // whitespace before
     self.newline(self.whitespace.getNewlinesBefore(comment));
 

lib/6to5/generation/generators/expressions.js

@@ -1,5 +1,6 @@
 var util = require("../../util");
 var t    = require("../../types");
+var _    = require("lodash");
 
 exports.UnaryExpression = function (node, print) {
   var hasSpace = /[a-z]$/.test(node.operator);
@@ -18,12 +19,6 @@ exports.UnaryExpression = function (node, print) {
   print(node.argument);
 };
 
-exports.ParenthesizedExpression = function (node, print) {
-  this.push("(");
-  print(node.expression);
-  this.push(")");
-};
-
 exports.UpdateExpression = function (node, print) {
   if (node.prefix) {
     this.push(node.operator);
@@ -92,22 +87,35 @@ exports.ExpressionStatement = function (node, print) {
 
 exports.BinaryExpression =
 exports.LogicalExpression =
+exports.AssignmentPattern =
 exports.AssignmentExpression = function (node, print) {
   print(node.left);
   this.push(" " + node.operator + " ");
   print(node.right);
 };
 
-exports.MemberExpression = function (node, print) {
-  print(node.object);
+var SCIENTIFIC_NOTATION = /e/i;
 
-  if (node.computed) {
+exports.MemberExpression = function (node, print) {
+  var obj = node.object;
+  print(obj);
+
+  if (!node.computed && t.isMemberExpression(node.property)) {
+    throw new TypeError("Got a MemberExpression for MemberExpression property");
+  }
+
+  var computed = node.computed;
+  if (t.isLiteral(node.property) && _.isNumber(node.property.value)) {
+    computed = true;
+  }
+
+  if (computed) {
     this.push("[");
     print(node.property);
     this.push("]");
   } else {
     // 5..toFixed(2);
-    if (t.isLiteral(node.object) && util.isInteger(node.object.value)) {
+    if (t.isLiteral(obj) && util.isInteger(obj.value) && !SCIENTIFIC_NOTATION.test(obj.value.toString())) {
       this.push(".");
     }
 

lib/6to5/generation/generators/flow.js

@@ -0,0 +1,3 @@
+exports.ClassProperty = function () {
+  throw new Error("not implemented");
+};

lib/6to5/generation/generators/modules.js

@@ -1,7 +1,14 @@
 var t = require("../../types");
 var _ = require("lodash");
 
-exports.ImportSpecifier =
+exports.ImportSpecifier = function (node, print) {
+  if (node.id && node.id.name === "default") {
+    print(node.name);
+  } else {
+    return exports.ExportSpecifier.apply(this, arguments);
+  }
+};
+
 exports.ExportSpecifier = function (node, print) {
   print(node.id);
   if (node.name) {
@@ -62,7 +69,9 @@ exports.ImportDeclaration = function (node, print) {
         self.push(", ");
       }
 
-      if (!spec.default && spec.type !== "ImportBatchSpecifier" && !foundImportSpecifier) {
+      var isDefault = spec.id && spec.id.name === "default";
+
+      if (!isDefault && spec.type !== "ImportBatchSpecifier" && !foundImportSpecifier) {
         foundImportSpecifier = true;
         self.push("{ ");
       }

lib/6to5/generation/generators/statements.js

@@ -146,7 +146,7 @@ exports.SwitchCase = function (node, print) {
     this.push("default:");
   }
 
-  this.space();
+  this.newline();
   print.sequence(node.consequent, { indent: true });
 };
 
@@ -164,6 +164,12 @@ exports.VariableDeclaration = function (node, print, parent) {
   }
 };
 
+exports.PrivateDeclaration = function (node, print) {
+  this.push("private ");
+  print.join(node.declarations, { separator: ", " });
+  this.semicolon();
+};
+
 exports.VariableDeclarator = function (node, print) {
   if (node.init) {
     print(node.id);

lib/6to5/generation/generators/types.js

@@ -84,8 +84,8 @@ exports.Literal = function (node) {
   if (type === "string") {
     val = JSON.stringify(val);
 
-    // escape unicode characters
-    val = val.replace(/[\u007f-\uffff]/g, function (c) {
+    // escape illegal js but valid json unicode characters
+    val = val.replace(/[\u000A\u000D\u2028\u2029]/g, function (c) {
       return "\\u" + ("0000" + c.charCodeAt(0).toString(16)).slice(-4);
     });
 

lib/6to5/generation/node/index.js

@@ -61,14 +61,40 @@ Node.prototype.needsParens = function () {
   if (!parent) return false;
 
   if (t.isNewExpression(parent) && parent.callee === node) {
-    return t.isCallExpression(node) || _.some(node, function (val) {
+    if (t.isCallExpression(node)) return true;
+
+    var hasCall = _.some(node, function (val) {
       return t.isCallExpression(val);
     });
+    if (hasCall) return true;
   }
 
   return find(parens, node, parent);
 };
 
+Node.prototype.needsParensNoLineTerminator = function () {
+  var parent = this.parent;
+  var node   = this.node;
+
+  if (!parent) return false;
+
+  // no comments
+  if (!node.leadingComments || !node.leadingComments.length) {
+    return false;
+  }
+
+  if (t.isYieldExpression(parent) || t.isAwaitExpression(parent)) {
+    return true;
+  }
+
+  if (t.isContinueStatement(parent) || t.isBreakStatement(parent) ||
+      t.isReturnStatement(parent) || t.isThrowStatement(parent)) {
+    return true;
+  }
+
+  return false;
+};
+
 _.each(Node.prototype, function (fn, key) {
   Node[key] = function (node, parent) {
     var n = new Node(node, parent);

lib/6to5/generation/node/parentheses.js

@@ -13,15 +13,30 @@ _.each([
   ["<", ">", "<=", ">=", "in", "instanceof"],
   [">>", "<<", ">>>"],
   ["+", "-"],
-  ["*", "/", "%"]
+  ["*", "/", "%"],
+  ["**"]
 ], function (tier, i) {
   _.each(tier, function (op) {
     PRECEDENCE[op] = i;
   });
 });
 
+exports.ObjectExpression = function (node, parent) {
+  if (t.isExpressionStatement(parent)) {
+    // ({ foo: "bar" });
+    return true;
+  }
+
+  if (t.isMemberExpression(parent) && parent.object === node) {
+    // ({ foo: "bar" }).foo
+    return true;
+  }
+
+  return false;
+};
+
 exports.Binary = function (node, parent) {
-  if (t.isCallExpression(parent) && parent.callee === node) {
+  if ((t.isCallExpression(parent) || t.isNewExpression(parent)) && parent.callee === node) {
     return true;
   }
 
@@ -92,13 +107,6 @@ exports.YieldExpression = function (node, parent) {
          t.isYieldExpression(parent);
 };
 
-exports.Literal = function (node, parent) {
-  // (1).valueOf()
-  if (_.isNumber(node.value) && t.isMemberExpression(parent) && parent.object === node) {
-    return true;
-  }
-};
-
 exports.ClassExpression = function (node, parent) {
   return t.isExpressionStatement(parent);
 };

lib/6to5/generation/node/whitespace.js

@@ -28,7 +28,13 @@ exports.before = {
 };
 
 exports.after = {
-  nodes: {},
+  nodes: {
+    AssignmentExpression: function (node) {
+      if (t.isFunction(node.right)) {
+        return 1;
+      }
+    }
+  },
 
   list: {
     VariableDeclaration: function (node) {
@@ -49,6 +55,8 @@ _.each({
   Function: 1,
   Class: 1,
   For: 1,
+  ArrayExpression: { after: 1 },
+  ObjectExpression: { after: 1 },
   SwitchStatement: 1,
   IfStatement: { before: 1 },
   CallExpression: { after: 1 },

lib/6to5/generation/whitespace.js

@@ -38,7 +38,11 @@ Whitespace.prototype.getNewlinesAfter = function (node) {
     }
   });
 
-  return this.getNewlinesBetween(startToken, endToken);
+  if (endToken.type.type === "eof") {
+    return 1;
+  } else {
+    return this.getNewlinesBetween(startToken, endToken);
+  }
 };
 
 Whitespace.prototype.getNewlinesBetween = function (startToken, endToken) {

lib/6to5/index.js

@@ -3,7 +3,9 @@ var util      = require("./util");
 var fs        = require("fs");
 var _         = require("lodash");
 
-exports.runtime = require("./runtime");
+exports.types = require("./types");
+
+exports.runtime = require("./runtime-generator");
 
 exports.register = function (opts) {
   var register = require("./register");

lib/6to5/patch.js

@@ -1,21 +1,22 @@
 var t = require("./types");
 var _ = require("lodash");
 
+// estraverse
+
+var estraverse = require("estraverse");
+_.extend(estraverse.VisitorKeys, t.VISITOR_KEYS);
+
+// regenerator/recast/ast-types
+
 var types = require("ast-types");
 var def   = types.Type.def;
 var or    = types.Type.or;
 
-// Program wrapper
-def("File")
-  .bases("Node")
-  .build("program")
-  .field("program", def("Program"));
-
-// Non-standard Acorn type
-def("ParenthesizedExpression")
-  .bases("Expression")
-  .build("expression")
-  .field("expression", def("Expression"));
+def("AssignmentPattern")
+    .bases("Pattern")
+    .build("left", "right")
+    .field("left", def("Pattern"))
+    .field("right", def("Expression"));
 
 // Acorn - Same as ImportNamespaceSpecifier but `id` is `name`
 def("ImportBatchSpecifier")
@@ -30,6 +31,11 @@ def("VirtualPropertyExpression")
   .field("object", def("Expression"))
   .field("property", or(def("Identifier"), def("Expression")));
 
+def("PrivateDeclaration")
+  .bases("Declaration")
+  .build("declarations")
+  .field("declarations", [def("Identifier")]);
+
 // Playground
 def("BindMemberExpression")
   .bases("Expression")
@@ -45,6 +51,3 @@ def("BindFunctionExpression")
   .field("arguments", [def("Expression")]);
 
 types.finalize();
-
-var estraverse = require("estraverse");
-_.extend(estraverse.VisitorKeys, t.VISITOR_KEYS);

lib/6to5/polyfill.js

@@ -1,37 +1,2 @@
-/* jshint newcap: false */
-
-var ensureSymbol = function (key) {
-  Symbol[key] = Symbol[key] || Symbol();
-};
-
-var ensureProto = function (Constructor, key, val) {
-  var proto = Constructor.prototype;
-  proto[key] = proto[key] || val;
-};
-
-//
-
-if (typeof Symbol === "undefined") {
-  require("es6-symbol/implement");
-}
-
-require("es6-shim");
-require("./transformation/transformers/es6-generators/runtime");
-
-// Abstract references
-
-ensureSymbol("referenceGet");
-ensureSymbol("referenceSet");
-ensureSymbol("referenceDelete");
-
-ensureProto(Function, Symbol.referenceGet, function () { return this; });
-
-ensureProto(Map, Symbol.referenceGet, Map.prototype.get);
-ensureProto(Map, Symbol.referenceSet, Map.prototype.set);
-ensureProto(Map, Symbol.referenceDelete, Map.prototype.delete);
-
-if (global.WeakMap) {
-  ensureProto(WeakMap, Symbol.referenceGet, WeakMap.prototype.get);
-  ensureProto(WeakMap, Symbol.referenceSet, WeakMap.prototype.set);
-  ensureProto(WeakMap, Symbol.referenceDelete, WeakMap.prototype.delete);
-}
+require("core-js/shim");
+require("regenerator/runtime");

lib/6to5/register-browser.js

@@ -0,0 +1,4 @@
+// Required to safely use 6to5/register within a browserify codebase.
+module.exports = function () {};
+
+require("./polyfill");

lib/6to5/register.js

@@ -1,7 +1,7 @@
 require("./polyfill");
 
 var sourceMapSupport = require("source-map-support");
-var roadrunner       = require('roadrunner');
+var roadrunner       = require("roadrunner");
 var util             = require("./util");
 var to5              = require("./index");
 var fs               = require("fs");
@@ -39,15 +39,22 @@ var blacklistTest = function (transformer, code) {
 };
 
 blacklistTest("arrayComprehension", "var foo = [for (foo of bar) foo * foo];");
-//blacklistTest("generatorComprehension", "");
+blacklistTest("generatorComprehension", "var foo = (for (foo of bar) foo * foo)");
 blacklistTest("arrowFunctions", "var foo = x => x * x;");
 blacklistTest("classes", "class Foo {}");
 blacklistTest("computedPropertyNames", "var foo = { [foo]: bar };");
-//blacklistTest("constants", "const foo = 0;");
+blacklistTest("constants", function () {
+  try {
+    new Function("const foo = 'foo';\nfoo = 'wow';");
+  } catch (err) {
+    return; // constants are supported
+  }
+  throw new SyntaxError;
+});
 blacklistTest("defaultParamaters", "var foo = function (bar = 0) {};");
 blacklistTest("destructuring", "var { x, y } = { x: 0, y: 0 };");
 blacklistTest("forOf", "for (var foo of bar) {}");
-blacklistTest("generators", "function* foo() {}");
+blacklistTest("generators", "function* foo() {}\nasync function bar() {}"); // generators/async functions delegated to same transformer
 blacklistTest("letScoping", "let foo = 0;");
 blacklistTest("modules", 'import foo from "from";');
 blacklistTest("propertyMethodAssignment", "{ get foo() {} }");
@@ -79,15 +86,18 @@ var loader = function (m, filename) {
 
   var result;
 
-  if (cache && cache[filename].mtime === mtime(filename)) {
-    result = cache[filename];
+  if (cache) {
+    var cached = cache[filename];
+    if (cached && cached.mtime === mtime(filename)) {
+      result = cached;
+    }
   }
 
   result = result || to5.transformFileSync(filename, _.extend({
     whitelist: whitelist,
     blacklist: blacklist,
     sourceMap: true,
-    modules:   "commonInterop"
+    ast:       false
   }, transformOpts));
 
   if (cache) {
@@ -113,7 +123,7 @@ var hookExtensions = function (_exts) {
   });
 };
 
-hookExtensions([".es6", ".js"]);
+hookExtensions([".es6", ".es", ".js"]);
 
 module.exports = function (opts) {
   // normalise options
@@ -126,8 +136,13 @@ module.exports = function (opts) {
 
   if (opts.extensions) hookExtensions(util.arrayify(opts.extensions));
 
-  if (opts.cache) cache = roadrunner.get('6to5');
+  if (opts.cache) cache = opts.cache;
   if (opts.cache === false) cache = null;
+  if (opts.cache === true) {
+    roadrunner.load();
+    roadrunner.setup();
+    cache = roadrunner.get("6to5");
+  }
 
   _.extend(transformOpts, opts);
 };

lib/6to5/runtime-generator.js

@@ -18,7 +18,11 @@ module.exports = function (namespace) {
     )
   ]));
 
-  _.each(File.declarations, function (name) {
+  _.each(File.helpers, function (name) {
+    if (_.contains(File.excludeHelpersFromRuntime, name)) {
+      return false;
+    }
+
     var key = t.identifier(t.toIdentifier(name));
     body.push(t.expressionStatement(
       t.assignmentExpression("=", t.memberExpression(namespace, key), util.template(name))

lib/6to5/templates/array-expression-comprehension-filter.js

@@ -1,5 +0,0 @@
-ARRAY.filter(function (KEY) {
-  return FILTER;
-}).map(function (KEY) {
-  return STATEMENT;
-});

lib/6to5/templates/array-expression-comprehension-map.js

@@ -1,3 +0,0 @@
-ARRAY.map(function (KEY) {
-  return STATEMENT;
-});

lib/6to5/templates/class-super-constructor-call.js

@@ -1,2 +0,0 @@
-SUPER_NAME.apply(this, arguments);
-

lib/6to5/templates/class.js

@@ -1,7 +0,0 @@
-(function () {
-  var CLASS_NAME = function () {
-
-  };
-
-  return CLASS_NAME;
-})()

lib/6to5/templates/exports-assign-key.js

@@ -1 +0,0 @@
-exports.VARIABLE_NAME = OBJECT.KEY;

lib/6to5/templates/exports-default.js

@@ -1 +0,0 @@
-exports.default = VALUE;

lib/6to5/templates/exports-wildcard.js

@@ -1,5 +0,0 @@
-(function (obj) {
-  for (var i in obj) {
-    exports[i] = obj[i];
-  }
-})(OBJECT);

lib/6to5/templates/extends.js

@@ -1,11 +0,0 @@
-(function (child, parent) {
-  child.prototype = Object.create(parent.prototype, {
-    constructor: {
-      value: child,
-      enumerable: false,
-      writable: true,
-      configurable: true
-    }
-  });
-  child.__proto__ = parent;
-})

lib/6to5/templates/function-return-obj.js

@@ -1,3 +0,0 @@
-(function (KEY) {
-  return KEY;
-})(OBJECT)

lib/6to5/templates/if-undefined-set-to.js

@@ -1 +0,0 @@
-if (VARIABLE === undefined) VARIABLE = DEFAULT;

lib/6to5/templates/register.js

@@ -1 +0,0 @@
-System.register(MODULE_NAME, MODULE_DEPENDENCIES, MODULE_BODY);

lib/6to5/templates/require-assign.js

@@ -1 +0,0 @@
-var VARIABLE_NAME = require(MODULE_NAME);

lib/6to5/templates/tagged-template-literal.js

@@ -1,4 +0,0 @@
-(function (strings, raw) {
-  return Object.defineProperties(strings, { raw: { value: raw } });
-});
-

lib/6to5/transformation/modules/_default.js

@@ -0,0 +1,212 @@
+module.exports = DefaultFormatter;
+
+var traverse = require("../../traverse");
+var util     = require("../../util");
+var t        = require("../../types");
+var _        = require("lodash");
+
+function DefaultFormatter(file) {
+  this.file = file;
+
+  this.localExports = this.getLocalExports();
+  this.remapAssignments();
+}
+
+DefaultFormatter.prototype.getLocalExports = function () {
+  var localExports = {};
+
+  traverse(this.file.ast, {
+    enter: function (node) {
+      var declar = node && node.declaration;
+      if (t.isExportDeclaration(node) && declar && t.isStatement(declar)) {
+        _.extend(localExports, t.getIds(declar, true));
+      }
+    }
+  });
+
+  return localExports;
+};
+
+DefaultFormatter.prototype.remapExportAssignment = function (node) {
+  return t.assignmentExpression(
+    "=",
+    node.left,
+    t.assignmentExpression(
+      node.operator,
+      t.memberExpression(t.identifier("exports"), node.left),
+      node.right
+    )
+  );
+};
+
+DefaultFormatter.prototype.remapAssignments = function () {
+  var localExports = this.localExports;
+  var self = this;
+
+  var isLocalReference = function (node, scope) {
+    var name = node.name;
+    return t.isIdentifier(node) && localExports[name] && localExports[name] === scope.get(name, true);
+  };
+
+  traverse(this.file.ast, {
+    enter: function (node, parent, scope) {
+      if (t.isUpdateExpression(node) && isLocalReference(node.argument, scope)) {
+        this.skip();
+
+        // expand to long file assignment expression
+        var assign = t.assignmentExpression(node.operator[0] + "=", node.argument, t.literal(1));
+
+        // remap this assignment expression
+        var remapped = self.remapExportAssignment(assign);
+
+        // we don't need to change the result
+        if (t.isExpressionStatement(parent) || node.prefix) {
+          return remapped;
+        }
+
+        var nodes = [];
+        nodes.push(remapped);
+
+        var operator;
+        if (node.operator === "--") {
+          operator = "+";
+        } else { // "++"
+          operator = "-";
+        }
+        nodes.push(t.binaryExpression(operator, node.argument, t.literal(1)));
+
+        return t.sequenceExpression(nodes);
+      }
+
+      if (t.isAssignmentExpression(node) && isLocalReference(node.left, scope)) {
+        this.skip();
+        return self.remapExportAssignment(node);
+      }
+    }
+  });
+};
+
+DefaultFormatter.prototype.getModuleName = function () {
+  var opts = this.file.opts;
+  var filenameRelative = opts.filenameRelative;
+  var moduleName = "";
+
+  if (opts.moduleRoot) {
+    moduleName = opts.moduleRoot + "/";
+  }
+
+  if (!opts.filenameRelative) {
+    return moduleName + opts.filename.replace(/^\//, "");
+  }
+
+  if (opts.sourceRoot) {
+    // remove sourceRoot from filename
+    var sourceRootRegEx = new RegExp("^" + opts.sourceRoot + "\/?");
+    filenameRelative = filenameRelative.replace(sourceRootRegEx, "");
+  }
+
+  // remove extension
+  filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
+
+  moduleName += filenameRelative;
+
+  return moduleName;
+};
+
+DefaultFormatter.prototype._pushStatement = function (ref, nodes) {
+  if (t.isClass(ref) || t.isFunction(ref)) {
+    if (ref.id) {
+      nodes.push(t.toStatement(ref));
+      ref = ref.id;
+    }
+  }
+
+  return ref;
+};
+
+DefaultFormatter.prototype._hoistExport = function (declar, assign, priority) {
+  if (t.isFunctionDeclaration(declar)) {
+    assign._blockHoist = priority || 2;
+  }
+
+  return assign;
+};
+
+DefaultFormatter.prototype._exportSpecifier = function (getRef, specifier, node, nodes) {
+  var inherits = false;
+  if (node.specifiers.length === 1) inherits = node;
+
+  if (node.source) {
+    if (t.isExportBatchSpecifier(specifier)) {
+      // export * from "foo";
+      nodes.push(this._exportsWildcard(getRef(), node));
+    } else {
+      var ref;
+      if (t.isSpecifierDefault(specifier.id) || this.noInteropRequire) {
+        ref = t.memberExpression(getRef(), specifier.id);
+      } else {
+        ref = t.callExpression(this.file.addHelper("interop-require"), [getRef()]);
+      }
+
+      // export { foo } from "test";
+      nodes.push(this._exportsAssign(
+        t.getSpecifierName(specifier),
+        ref,
+        node
+      ));
+    }
+  } else {
+    // export { foo };
+    nodes.push(this._exportsAssign(t.getSpecifierName(specifier), specifier.id, node));
+  }
+};
+
+DefaultFormatter.prototype._exportsWildcard = function (objectIdentifier) {
+  return t.expressionStatement(t.callExpression(this.file.addHelper("exports-wildcard"), [
+    t.callExpression(this.file.addHelper("interop-require-wildcard"), [objectIdentifier])
+  ]));
+};
+
+DefaultFormatter.prototype._exportsAssign = function (id, init) {
+  return util.template("exports-assign", {
+    VALUE: init,
+    KEY:   id
+  }, true);
+};
+
+DefaultFormatter.prototype.exportDeclaration = function (node, nodes) {
+  var declar = node.declaration;
+
+  var id = declar.id;
+
+  if (node.default) {
+    id = t.identifier("default");
+  }
+
+  var assign;
+
+  if (t.isVariableDeclaration(declar)) {
+    for (var i in declar.declarations) {
+      var decl = declar.declarations[i];
+
+      decl.init = this._exportsAssign(decl.id, decl.init, node).expression;
+
+      var newDeclar = t.variableDeclaration(declar.kind, [decl]);
+      if (i === "0") t.inherits(newDeclar, declar);
+      nodes.push(newDeclar);
+    }
+  } else {
+    var ref = declar;
+
+    if (t.isFunctionDeclaration(declar) || t.isClassDeclaration(declar)) {
+      ref = declar.id;
+      nodes.push(declar);
+    }
+
+    assign = this._exportsAssign(id, ref, node);
+
+    nodes.push(assign);
+
+    this._hoistExport(declar, assign);
+  }
+};

lib/6to5/transformation/modules/amd.js

@@ -1,16 +1,28 @@
 module.exports = AMDFormatter;
 
-var CommonJSFormatter = require("./common");
-var util              = require("../../util");
-var t                 = require("../../types");
-var _                 = require("lodash");
+var DefaultFormatter = require("./_default");
+var util             = require("../../util");
+var t                = require("../../types");
+var _                = require("lodash");
 
-function AMDFormatter(file) {
-  this.file = file;
+function AMDFormatter() {
+  DefaultFormatter.apply(this, arguments);
   this.ids  = {};
 }
 
-util.inherits(AMDFormatter, CommonJSFormatter);
+util.inherits(AMDFormatter, DefaultFormatter);
+
+AMDFormatter.prototype.buildDependencyLiterals = function () {
+  var names = [];
+  for (var name in this.ids) {
+    names.push(t.literal(name));
+  }
+  return names;
+};
+
+/**
+ * Wrap the entire body in a `define` wrapper.
+ */
 
 AMDFormatter.prototype.transform = function (ast) {
   var program = ast.program;
@@ -18,10 +30,7 @@ AMDFormatter.prototype.transform = function (ast) {
 
   // build an array of module names
 
-  var names = [t.literal("exports")];
-  _.each(this.ids, function (id, name) {
-    names.push(t.literal(name));
-  });
+  var names = [t.literal("exports")].concat(this.buildDependencyLiterals());
   names = t.arrayExpression(names);
 
   // build up define container
@@ -40,9 +49,14 @@ AMDFormatter.prototype.transform = function (ast) {
   program.body = [t.expressionStatement(call)];
 };
 
+/**
+ * Get the AMD module name that we'll prepend to the wrapper
+ * to define this module
+ */
+
 AMDFormatter.prototype.getModuleName = function () {
-  if (this.file.opts.amdModuleIds) {
-    return CommonJSFormatter.prototype.getModuleName.apply(this, arguments);
+  if (this.file.opts.moduleIds) {
+    return DefaultFormatter.prototype.getModuleName.apply(this, arguments);
   } else {
     return null;
   }
@@ -59,27 +73,22 @@ AMDFormatter.prototype._push = function (node) {
   }
 };
 
-AMDFormatter.prototype.import = function (node) {
+AMDFormatter.prototype.importDeclaration = function (node) {
   this._push(node);
 };
 
 AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
-  var id  = specifier.id;
-
-  // import foo from "foo";
-  if (specifier.default) {
-    id = t.identifier("default");
-  }
-
-  var ref;
+  var ref = this._push(node);
 
   if (t.isImportBatchSpecifier(specifier)) {
     // import * as bar from "foo";
-    ref = this._push(node);
-  } else {
+  } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
     // import foo from "foo";
-    ref = t.memberExpression(this._push(node), id, false);
+    ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
+  } else {
+    // import {foo} from "foo";
+    ref = t.memberExpression(ref, specifier.id, false);
   }
 
   nodes.push(t.variableDeclaration("var", [

lib/6to5/transformation/modules/common-interop.js

@@ -1,56 +0,0 @@
-module.exports = CommonJSInteropFormatter;
-
-var CommonJSFormatter = require("./common");
-var util              = require("../../util");
-var t                 = require("../../types");
-var _                 = require("lodash");
-
-function CommonJSInteropFormatter(file) {
-  CommonJSFormatter.apply(this, arguments);
-
-  var has = false;
-  _.each(file.ast.program.body, function (node) {
-    if (t.isExportDeclaration(node) && !node.default) has = true;
-  });
-  this.has = has;
-}
-
-util.inherits(CommonJSInteropFormatter, CommonJSFormatter);
-
-CommonJSInteropFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
-  var variableName = t.getSpecifierName(specifier);
-
-  // import foo from "foo";
-   if (specifier.default) {
-    nodes.push(t.variableDeclaration("var", [
-      t.variableDeclarator(variableName,
-        t.callExpression(this.file.addDeclaration("interop-require"), [util.template("require", {
-          MODULE_NAME: node.source.raw
-        })])
-      )
-    ]));
-  } else {
-    CommonJSFormatter.prototype.importSpecifier.apply(this, arguments);
-  }
-};
-
-CommonJSInteropFormatter.prototype.export = function (node, nodes) {
-  if (node.default && !this.has) {
-    var declar = node.declaration;
-
-    // module.exports = VALUE;
-    var assign = util.template("exports-default-module", {
-      VALUE: this._pushStatement(declar, nodes)
-    }, true);
-
-    // hoist to the top if this default is a function
-    nodes.push(this._hoistExport(declar, assign));
-    return;
-  }
-
-  CommonJSFormatter.prototype.export.apply(this, arguments);
-};
-
-CommonJSInteropFormatter.prototype.exportSpecifier = function () {
-  CommonJSFormatter.prototype.exportSpecifier.apply(this, arguments);
-};

lib/6to5/transformation/modules/common.js

@@ -1,162 +1,99 @@
 module.exports = CommonJSFormatter;
 
-var util = require("../../util");
-var t    = require("../../types");
+var DefaultFormatter = require("./_default");
+var traverse         = require("../../traverse");
+var util             = require("../../util");
+var t                = require("../../types");
 
 function CommonJSFormatter(file) {
-  this.file = file;
+  DefaultFormatter.apply(this, arguments);
+
+  var hasNonDefaultExports = false;
+  traverse(file.ast, {
+    enter: function (node) {
+      if (t.isExportDeclaration(node) && !node.default) hasNonDefaultExports = true;
+    }
+  });
+  this.hasNonDefaultExports = hasNonDefaultExports;
 }
 
-CommonJSFormatter.prototype.getModuleName = function () {
-  var opts = this.file.opts;
-  var filenameRelative = opts.filenameRelative;
-  var moduleName = "";
-
-  if (opts.moduleRoot) {
-    moduleName = opts.moduleRoot + "/";
-  }
-
-  if (!opts.filenameRelative) {
-    return moduleName + opts.filename.replace(/^\//, "");
-  }
-
-  if (opts.sourceRoot) {
-    // remove sourceRoot from filename
-    var sourceRootRegEx = new RegExp("^" + opts.sourceRoot + "\/?");
-    filenameRelative = filenameRelative.replace(sourceRootRegEx, "");
-  }
-
-  // remove extension
-  filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
-
-  moduleName += filenameRelative;
-
-  return moduleName;
-};
-
-CommonJSFormatter.prototype.import = function (node, nodes) {
-  // import "foo";
-  nodes.push(util.template("require", {
-    //inherits: node,
-
-    MODULE_NAME: node.source.raw
-  }, true));
-};
+util.inherits(CommonJSFormatter, DefaultFormatter);
 
 CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var variableName = t.getSpecifierName(specifier);
 
   // import foo from "foo";
-  if (specifier.default) {
-    specifier.id = t.identifier("default");
-  }
-
-  var templateName = "require-assign";
-
-  // import * as bar from "foo";
-  if (specifier.type !== "ImportBatchSpecifier") templateName += "-key";
-
-  nodes.push(util.template(templateName, {
-    //inherits: node.specifiers.length === 1 && node,
-
-    VARIABLE_NAME: variableName,
-    MODULE_NAME:   node.source.raw,
-    KEY:           specifier.id
-  }));
-};
-
-CommonJSFormatter.prototype._hoistExport = function (declar, assign) {
-  if (t.isFunctionDeclaration(declar)) {
-    assign._blockHoist = true;
-  }
-
-  return assign;
-};
-
-CommonJSFormatter.prototype._pushStatement = function (ref, nodes) {
-  if (t.isClass(ref) || t.isFunction(ref)) {
-    if (ref.id) {
-      nodes.push(t.toStatement(ref));
-      ref = ref.id;
+  if (t.isSpecifierDefault(specifier)) {
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(variableName,
+        t.callExpression(this.file.addHelper("interop-require"), [util.template("require", {
+          MODULE_NAME: node.source
+        })])
+      )
+    ]));
+  } else {
+    if (specifier.type === "ImportBatchSpecifier") {
+      // import * as bar from "foo";
+      nodes.push(t.variableDeclaration("var", [
+        t.variableDeclarator(
+          variableName,
+          t.callExpression(this.file.addHelper("interop-require-wildcard"), [
+            t.callExpression(t.identifier("require"), [node.source])
+          ])
+        )
+      ]));
+    } else {
+      // import foo from "foo";
+      nodes.push(util.template("require-assign-key", {
+        VARIABLE_NAME: variableName,
+        MODULE_NAME:   node.source,
+        KEY:           specifier.id
+      }));
     }
   }
-  return ref;
 };
 
-CommonJSFormatter.prototype.export = function (node, nodes) {
-  var declar = node.declaration;
+CommonJSFormatter.prototype.importDeclaration = function (node, nodes) {
+  // import "foo";
+  nodes.push(util.template("require", {
+    MODULE_NAME: node.source
+  }, true));
+};
 
+CommonJSFormatter.prototype.exportDeclaration = function (node, nodes) {
   if (node.default) {
-    nodes.push(util.template("exports-default", {
-      //inherits: node,
-
-      VALUE: this._pushStatement(declar, nodes)
-    }, true));
-  } else {
+    var declar = node.declaration;
     var assign;
 
-    if (t.isVariableDeclaration(declar)) {
-      var decl = declar.declarations[0];
+    // module.exports = VALUE;
+    var templateName = "exports-default-module";
 
-      if (decl.init) {
-        decl.init = util.template("exports-assign", {
-          //inherits: node,
+    // exports = module.exports = VALUE;
+    if (this.hasNonDefaultExports) templateName = "exports-default-module-override";
 
-          VALUE: decl.init,
-          KEY:   decl.id
-        });
-      }
-
-      nodes.push(declar);
-    } else {
-      assign = util.template("exports-assign", {
-        //inherits: node,
-
-        VALUE: declar.id,
-        KEY:   declar.id
+    if (t.isFunctionDeclaration(declar) || !this.hasNonDefaultExports) {
+      assign = util.template(templateName, {
+        VALUE: this._pushStatement(declar, nodes)
       }, true);
 
-      nodes.push(t.toStatement(declar));
-      nodes.push(assign);
-
-      this._hoistExport(declar, assign);
-    }
-  }
-};
-
-CommonJSFormatter.prototype._exportSpecifier = function (getRef, specifier, node, nodes) {
-  var variableName = t.getSpecifierName(specifier);
-
-  var inherits = false;
-  if (node.specifiers.length === 1) inherits = node;
-
-  if (node.source) {
-    if (t.isExportBatchSpecifier(specifier)) {
-      // export * from "foo";
-      nodes.push(util.template("exports-wildcard", {
-        //inherits: inherits,
-
-        OBJECT: getRef()
-      }, true));
+      // hoist to the top if this default is a function
+      nodes.push(this._hoistExport(declar, assign, 3));
+      return;
     } else {
-      // export { foo } from "test";
-      nodes.push(util.template("exports-assign-key", {
-        //inherits: inherits,
+      // this export isn't a function so we can't hoist it to the top so we need to set it
+      // at the very end of the file with something like:
+      //
+      //   module.exports = Object.assign(exports["default"], exports)
+      //
 
-        VARIABLE_NAME: variableName.name,
-        OBJECT:        getRef(),
-        KEY:           specifier.id
-      }, true));
+      assign = util.template("common-export-default-assign", true);
+      assign._blockHoist = 0;
+
+      nodes.push(assign);
     }
-  } else {
-    // export { foo };
-    nodes.push(util.template("exports-assign", {
-      //inherits: inherits,
-
-      VALUE: specifier.id,
-      KEY:   variableName
-    }, true));
   }
+
+  DefaultFormatter.prototype.exportDeclaration.apply(this, arguments);
 };
 
 CommonJSFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {

lib/6to5/transformation/modules/ignore.js

@@ -6,19 +6,13 @@ function IgnoreFormatter() {
 
 }
 
-IgnoreFormatter.prototype.import = function () {
-
-};
-
-IgnoreFormatter.prototype.importSpecifier = function () {
-
-};
-
-IgnoreFormatter.prototype.export = function (node, nodes) {
+IgnoreFormatter.prototype.exportDeclaration = function (node, nodes) {
   var declar = t.toStatement(node.declaration, true);
   if (declar) nodes.push(t.inherits(declar, node));
 };
 
+IgnoreFormatter.prototype.importDeclaration =
+IgnoreFormatter.prototype.importSpecifier =
 IgnoreFormatter.prototype.exportSpecifier = function () {
 
 };

lib/6to5/transformation/modules/system.js

@@ -1,202 +1,179 @@
 module.exports = SystemFormatter;
 
-var util = require("../../util");
-var t    = require("../../types");
-var _    = require("lodash");
-
-var SETTER_MODULE_NAMESPACE = t.identifier("m");
-var DEFAULT_IDENTIFIER      = t.identifier("default");
-var NULL_SETTER             = t.literal(null);
+var AMDFormatter = require("./amd");
+var useStrict    = require("../transformers/use-strict");
+var traverse     = require("../../traverse");
+var util         = require("../../util");
+var t            = require("../../types");
+var _            = require("lodash");
 
 function SystemFormatter(file) {
-  this.exportedStatements = [];
-  this.importedModule     = {};
+  this.exportIdentifier  = file.generateUidIdentifier("export");
+  this.noInteropRequire = true;
 
-  this.exportIdentifier   = file.generateUidIdentifier("export");
-  this.file               = file;
+  AMDFormatter.apply(this, arguments);
 }
 
+util.inherits(SystemFormatter, AMDFormatter);
+
+SystemFormatter.prototype._addImportSource = function (node, exportNode) {
+  node._importSource = exportNode.source && exportNode.source.value;
+  return node;
+};
+
+SystemFormatter.prototype._exportsWildcard = function (objectIdentifier, node) {
+  var leftIdentifier = this.file.generateUidIdentifier("key");
+  var valIdentifier  = t.memberExpression(objectIdentifier, leftIdentifier, true);
+
+  var left = t.variableDeclaration("var", [
+    t.variableDeclarator(leftIdentifier)
+  ]);
+
+  var right = objectIdentifier;
+
+  var block = t.blockStatement([
+    t.expressionStatement(this.buildExportCall(leftIdentifier, valIdentifier))
+  ]);
+
+  return this._addImportSource(t.forInStatement(left, right, block), node);
+};
+
+SystemFormatter.prototype._exportsAssign = function (id, init, node) {
+  var call = this.buildExportCall(t.literal(id.name), init, true);
+  return this._addImportSource(call, node);
+};
+
+SystemFormatter.prototype.remapExportAssignment = function (node) {
+  return this.buildExportCall(t.literal(node.left.name), node);
+};
+
+SystemFormatter.prototype.buildExportCall = function (id, init, isStatement) {
+  var call = t.callExpression(this.exportIdentifier, [id, init]);
+  if (isStatement) {
+    return t.expressionStatement(call);
+  } else {
+    return call;
+  }
+};
+
+SystemFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
+  AMDFormatter.prototype.importSpecifier.apply(this, arguments);
+  this._addImportSource(_.last(nodes), node);
+};
+
+SystemFormatter.prototype.buildRunnerSetters = function (block, hoistDeclarators) {
+  return t.arrayExpression(_.map(this.ids, function (uid, source) {
+    var nodes = [];
+
+    traverse(block, {
+      enter: function (node) {
+        if (node._importSource === source) {
+          if (t.isVariableDeclaration(node)) {
+            _.each(node.declarations, function (declar) {
+              hoistDeclarators.push(t.variableDeclarator(declar.id));
+              nodes.push(t.expressionStatement(
+                t.assignmentExpression("=", declar.id, declar.init)
+              ));
+            });
+          } else {
+            nodes.push(node);
+          }
+
+          this.remove();
+        }
+      }
+    });
+
+    return t.functionExpression(null, [uid], t.blockStatement(nodes));
+  }));
+};
+
 SystemFormatter.prototype.transform = function (ast) {
   var program = ast.program;
-  var body    = program.body;
 
-  // extract the module name
-  var moduleName = this.file.opts.filename
-    .replace(/^.*\//, "").replace(/\..*$/, "");
+  var hoistDeclarators = [];
+  var moduleName = this.getModuleName();
+  var moduleNameLiteral = t.literal(moduleName);
 
-  // build an array of module names
-  var dependencies = Object.keys(this.importedModule).map(t.literal);
+  var block = t.blockStatement(program.body);
 
-  // generate the __moduleName variable
-  var moduleNameVariableNode = t.variableDeclaration("var", [
-    t.variableDeclarator(
-      t.identifier("__moduleName"),
-      t.literal(moduleName)
-    )
-  ]);
-  body.splice(1, 0, moduleNameVariableNode);
+  var runner = util.template("system", {
+    MODULE_NAME: moduleNameLiteral,
+    MODULE_DEPENDENCIES: t.arrayExpression(this.buildDependencyLiterals()),
+    EXPORT_IDENTIFIER: this.exportIdentifier,
+    SETTERS: this.buildRunnerSetters(block, hoistDeclarators),
+    EXECUTE: t.functionExpression(null, [], block)
+  }, true);
 
-  // generate an array of import variables
+  var handlerBody = runner.expression.arguments[2].body.body;
+  if (!moduleName) runner.expression.arguments.shift();
 
-  var declaredSetters = _(this.importedModule)
-    .map()
-    .flatten()
-    .pluck("variableName")
-    .pluck("name")
-    .uniq()
-    .map(t.identifier)
-    .map(function (name) {
-      return t.variableDeclarator(name);
-    })
-    .value();
+  var returnStatement = handlerBody.pop();
 
-  if (declaredSetters.length) {
-    body.splice(2, 0, t.variableDeclaration("var", declaredSetters));
-  }
-
-  // generate the execute function expression
-  var executeFunctionExpression = t.functionExpression(
-    null, [], t.blockStatement(this.exportedStatements)
-  );
-
-  // generate the execute function expression
-  var settersArrayExpression = t.arrayExpression(this._buildSetters());
-
-  // generate the return statement
-  var moduleReturnStatement = t.returnStatement(t.objectExpression([
-    t.property("init", t.identifier("setters"), settersArrayExpression),
-    t.property("init", t.identifier("execute"), executeFunctionExpression)
-  ]));
-  body.push(moduleReturnStatement);
-
-  // runner
-  var runner = util.template("register", {
-    MODULE_NAME: t.literal(moduleName),
-    MODULE_DEPENDENCIES: t.arrayExpression(dependencies),
-    MODULE_BODY: t.functionExpression(
-      null,
-      [this.exportIdentifier],
-      t.blockStatement(body)
-    )
-  });
-
-  program.body = [t.expressionStatement(runner)];
-};
-
-SystemFormatter.prototype._buildSetters = function () {
-  // generate setters array expression elements
-  return _.map(this.importedModule, function (specs) {
-    if (!specs.length) {
-      return NULL_SETTER;
-    }
-
-    var expressionStatements = _.map(specs, function (spec) {
-      var right = SETTER_MODULE_NAMESPACE;
-      if (!spec.isBatch) {
-        right = t.memberExpression(right, spec.key);
+  // hoist up all variable declarations
+  traverse(block, {
+    enter: function (node, parent, scope) {
+      if (t.isFunction(node)) {
+        // nothing inside is accessible
+        return this.skip();
       }
 
-      return t.expressionStatement(
-        t.assignmentExpression("=", spec.variableName, right
-        )
-      );
-    });
+      if (t.isVariableDeclaration(node)) {
+        if (node.kind !== "var" && !t.isProgram(parent)) { // let, const
+          // can't be accessed
+          return;
+        }
 
-    return t.functionExpression(
-      null, [SETTER_MODULE_NAMESPACE], t.blockStatement(expressionStatements)
-    );
-  });
-};
+        var nodes = [];
 
-SystemFormatter.prototype.import = function (node) {
-  var MODULE_NAME = node.source.value;
-  this.importedModule[MODULE_NAME] = this.importedModule[MODULE_NAME] || [];
-};
+        _.each(node.declarations, function (declar) {
+          hoistDeclarators.push(t.variableDeclarator(declar.id));
+          if (declar.init) {
+            // no initializer so we can just hoist it as-is
+            var assign = t.expressionStatement(t.assignmentExpression("=", declar.id, declar.init));
+            nodes.push(assign);
+          }
+        });
 
-SystemFormatter.prototype.importSpecifier = function (specifier, node) {
-  var variableName = t.getSpecifierName(specifier);
+        // for (var i in test)
+        // for (var i = 0;;)
+        if (t.isFor(parent)) {
+          if (parent.left === node) {
+            return node.declarations[0].id;
+          }
 
-  // import foo from "foo";
-  if (specifier.default) {
-    specifier.id = DEFAULT_IDENTIFIER;
-  }
+          if (parent.init === node) {
+            return t.toSequenceExpression(nodes, scope);
+          }
+        }
 
-  var MODULE_NAME = node.source.value;
-
-  this.importedModule[MODULE_NAME] = this.importedModule[MODULE_NAME] || [];
-
-  this.importedModule[MODULE_NAME].push({
-    variableName: variableName,
-    isBatch:      specifier.type === "ImportBatchSpecifier",
-    key:          specifier.id
-  });
-};
-
-SystemFormatter.prototype._export = function (name, identifier) {
-  this.exportedStatements.push(t.expressionStatement(
-    t.callExpression(this.exportIdentifier, [t.literal(name), identifier])
-  ));
-};
-
-SystemFormatter.prototype.export = function (node, nodes) {
-  var declar = node.declaration;
-  var variableName, identifier;
-
-  if (node.default) {
-    // export default foo
-    variableName = DEFAULT_IDENTIFIER.name;
-    if (t.isClass(declar) || t.isFunction(declar)) {
-      if (!declar.id) {
-        declar.id = this.file.generateUidIdentifier("anonymous");
+        return nodes;
       }
-
-      nodes.push(t.toStatement(declar));
-      declar = declar.id;
     }
-
-    identifier = declar;
-  } else if (t.isVariableDeclaration(declar)) {
-    // export var foo
-    variableName = declar.declarations[0].id.name;
-    identifier = declar.declarations[0].id;
-
-    nodes.push(declar);
-  } else {
-    // export function foo () {}
-    variableName = declar.id.name;
-    identifier = declar.id;
-
-    nodes.push(declar);
+  });
+  if (hoistDeclarators.length) {
+    var hoistDeclar = t.variableDeclaration("var", hoistDeclarators);
+    hoistDeclar._blockHoist = true;
+    handlerBody.unshift(hoistDeclar);
   }
 
-  this._export(variableName, identifier);
-};
+  // hoist up function declarations for circular references
+  traverse(block, {
+    enter: function (node) {
+      if (t.isFunction(node)) this.skip();
 
-SystemFormatter.prototype.exportSpecifier = function (specifier, node) {
-  var variableName = t.getSpecifierName(specifier);
-
-  if (node.source) {
-    if (t.isExportBatchSpecifier(specifier)) {
-      // export * from "foo";
-      var exportIdentifier = t.identifier("exports");
-      this.exportedStatements.push(
-        t.variableDeclaration("var", [
-          t.variableDeclarator(exportIdentifier, this.exportIdentifier)
-        ])
-      );
-
-      this.exportedStatements.push(util.template("exports-wildcard", {
-        OBJECT: t.identifier(node.source.value)
-      }, true));
-    } else {
-      // export { foo } from "test";
-      this._export(variableName.name, t.memberExpression(
-        t.identifier(node.source.value),
-        specifier.id
-      ));
+      if (t.isFunctionDeclaration(node) || node._blockHoist) {
+        handlerBody.push(node);
+        this.remove();
+      }
     }
-  } else {
-    // export { foo };
-    this._export(variableName.name, specifier.id);
+  });
+
+  handlerBody.push(returnStatement);
+
+  if (useStrict._has(block)) {
+    handlerBody.unshift(block.body.shift());
   }
+
+  program.body = [runner];
 };

lib/6to5/transformation/modules/umd.js

@@ -18,9 +18,9 @@ UMDFormatter.prototype.transform = function (ast) {
   // build an array of module names
 
   var names = [];
-  _.each(this.ids, function (id, name) {
+  for (var name in this.ids) {
     names.push(t.literal(name));
-  });
+  }
 
   // factory
 

lib/6to5/transformation/templates/async-to-generator.js

@@ -0,0 +1,37 @@
+(function (fn) {
+  return function () {
+    var gen = fn.apply(this, arguments);
+
+    return new Promise(function (resolve, reject) {
+      function step(getNext) {
+        var next;
+
+        try {
+          next = getNext();
+        } catch(e) {
+          reject(e);
+          return;
+        }
+
+        if (next.done) {
+          resolve(next.value);
+          return;
+        }
+
+        Promise.resolve(next.value).then(function (v) {
+          step(function () {
+            return gen.next(v);
+          });
+        }, function (e) {
+          step(function () {
+            return gen["throw"](e);
+          });
+        });
+      }
+
+      step(function () {
+        return gen.next();
+      });
+    });
+  }
+})

lib/6to5/transformation/templates/bind.js

@@ -0,0 +1 @@
+Function.prototype.bind

lib/6to5/transformation/templates/class-super-constructor-call.js

@@ -0,0 +1,3 @@
+if (SUPER_NAME !== null) {
+  SUPER_NAME.apply(this, arguments);
+}

lib/6to5/transformation/templates/common-export-default-assign.js

@@ -0,0 +1 @@
+module.exports = Object.assign(exports["default"], exports);

lib/6to5/transformation/templates/corejs-iterator.js

@@ -0,0 +1 @@
+CORE_ID.$for.getIterator(VALUE);

lib/6to5/transformation/templates/default-parameter.js

@@ -0,0 +1 @@
+var VARIABLE_NAME = ARGUMENTS[ARGUMENT_KEY] === undefined ? DEFAULT_VALUE : ARGUMENTS[ARGUMENT_KEY];

lib/6to5/transformation/templates/defaults.js

@@ -0,0 +1,8 @@
+(function (obj, defaults) {
+  for (var key in defaults) {
+    if (obj[key] === undefined) {
+      obj[key] = defaults[key];
+    }
+  }
+  return obj;
+})

lib/6to5/transformation/templates/define-property.js

@@ -0,0 +1,8 @@
+(function (obj, key, value) {
+  return Object.defineProperty(obj, key, {
+    value: value,
+    enumerable: true,
+    configurable: true,
+    writable: true
+  });
+});

lib/6to5/transformation/templates/exports-default-module-override.js

@@ -0,0 +1 @@
+exports = module.exports = VALUE;