From b38c15a94bca0077b8f8ba07f67f1d02eb440663 Mon Sep 17 00:00:00 2001 From: Ingvar Stepanyan Date: Fri, 25 Jul 2014 20:58:46 +0300 Subject: [PATCH] Added export declaration support. See http://people.mozilla.org/~jorendorff/es6-draft.html#sec-exports, ariya/esprima#216, square/es6-module-transpiler#63 for latest decisions on `export default 42` vs `export default = 42` (first wins, so returning AST as it was in older Esprima Harmony and used by https://github.com/square/es6-module-transpiler/). --- acorn.js | 62 ++++++++++++++++++++++++++++++-- index.html | 58 +++++++++++++++++++++++++++--- test/tests-harmony.js | 82 ++++++++++++------------------------------- 3 files changed, 136 insertions(+), 66 deletions(-) diff --git a/acorn.js b/acorn.js index cb0e5694e6..60ee4c4f68 100644 --- a/acorn.js +++ b/acorn.js @@ -287,6 +287,8 @@ var _while = {keyword: "while", isLoop: true}, _with = {keyword: "with"}, _new = {keyword: "new", beforeExpr: true}; var _this = {keyword: "this"}; var _class = {keyword: "class"}, _extends = {keyword: "extends", beforeExpr: true}, _static = {keyword: "static"}; + var _module = {keyword: "module"}, _export = {keyword: "export"}; + var _import = {keyword: "import"}, _from = {keyword: "from"}, _as = {keyword: "as"}; // The keywords that denote values. @@ -313,7 +315,9 @@ "typeof": {keyword: "typeof", prefix: true, beforeExpr: true}, "void": {keyword: "void", prefix: true, beforeExpr: true}, "delete": {keyword: "delete", prefix: true, beforeExpr: true}, - "class": _class, "extends": _extends, "static": _static, "of": _of}; + "class": _class, "extends": _extends, "static": _static, "of": _of, + "module": _module, "export": _export, "import": _import, + "from": _from, "as": _as}; // Punctuation token types. Again, the `type` property is purely for debugging. @@ -432,7 +436,7 @@ var isEcma5AndLessKeyword = makePredicate(ecma5AndLessKeywords); - var isEcma6Keyword = makePredicate(ecma5AndLessKeywords + " let const class extends static of"); + var isEcma6Keyword = makePredicate(ecma5AndLessKeywords + " let const class extends static of module export import from as"); var isKeyword = isEcma5AndLessKeyword; @@ -1249,6 +1253,7 @@ case _with: return parseWithStatement(node); case _braceL: return parseBlock(); // no point creating a function for this case _semi: return parseEmptyStatement(node); + case _export: return parseExport(node); // If the statement does not start with a statement keyword or a // brace, it's an ExpressionStatement or LabeledStatement. We @@ -2169,4 +2174,57 @@ unexpected(node.start); } + // Parses module export declaration. + + function parseExport(node) { + next(); + if (tokType === _var || tokType === _const || tokType === _let || tokType === _function || tokType === _class) { + node.declaration = parseStatement(); + node.default = false; + node.specifiers = null; + node.source = null; + } else + if (eat(_default)) { + node.declaration = parseExpression(true); + node.default = true; + node.specifiers = null; + node.source = null; + semicolon(); + } else + if (tokVal === '*') { + node.declaration = null; + node.default = false; + var specifier = startNode(); + next(); + node.specifiers = [finishNode(specifier, "ExportBatchSpecifier")]; + expect(_from); + node.source = tokType === _string ? parseExprAtom() : unexpected(); + } else + if (eat(_braceL)) { + node.declaration = null; + node.default = false; + node.specifiers = parseModuleSpecifiers("ExportSpecifier"); + node.source = eat(_from) ? (tokType === _string ? parseExprAtom() : unexpected()) : null; + } else unexpected(); + return finishNode(node, "ExportDeclaration"); + } + + // Parses a comma-separated list of module imports/exports. + + function parseModuleSpecifiers(type) { + var nodes = [], first = true; + while (!eat(_braceR)) { + if (!first) { + expect(_comma); + if (options.allowTrailingCommas && eat(_braceR)) break; + } else first = false; + + var node = startNode(); + node.id = parseIdent(); + node.name = eat(_as) ? parseIdent(true) : null; + nodes.push(finishNode(node, type)); + } + return nodes; + } + }); diff --git a/index.html b/index.html index 88ea6a3263..72770c4329 100644 --- a/index.html +++ b/index.html @@ -178,7 +178,9 @@ continue jumps to that label.

var _let = {keyword: "let"}, _const = {keyword: "const"}; var _while = {keyword: "while", isLoop: true}, _with = {keyword: "with"}, _new = {keyword: "new", beforeExpr: true}; var _this = {keyword: "this"}; - var _class = {keyword: "class"}, _extends = {keyword: "extends", beforeExpr: true}, _static = {keyword: "static"};

The keywords that denote values.

  var _null = {keyword: "null", atomValue: null}, _true = {keyword: "true", atomValue: true};
+  var _class = {keyword: "class"}, _extends = {keyword: "extends", beforeExpr: true}, _static = {keyword: "static"};
+  var _module = {keyword: "module"}, _export = {keyword: "export"};
+  var _import = {keyword: "import"}, _from = {keyword: "from"}, _as = {keyword: "as"};

The keywords that denote values.

  var _null = {keyword: "null", atomValue: null}, _true = {keyword: "true", atomValue: true};
   var _false = {keyword: "false", atomValue: false};

Some keywords are treated as regular operators. in sometimes (when parsing for) needs to be tested against specifically, so we assign a variable name to it for quick comparing.

  var _in = {keyword: "in", binop: 7, beforeExpr: true};
@@ -193,7 +195,9 @@ we assign a variable name to it for quick comparing.
             
                       "typeof": {keyword: "typeof", prefix: true, beforeExpr: true},
                       "void": {keyword: "void", prefix: true, beforeExpr: true},
                       "delete": {keyword: "delete", prefix: true, beforeExpr: true},
-                      "class": _class, "extends": _extends, "static": _static, "of": _of};

Punctuation token types. Again, the type property is purely for debugging.

  var _bracketL = {type: "[", beforeExpr: true}, _bracketR = {type: "]"}, _braceL = {type: "{", beforeExpr: true};
+                      "class": _class, "extends": _extends, "static": _static, "of": _of,
+                      "module": _module, "export": _export, "import": _import,
+                      "from": _from, "as": _as};

Punctuation token types. Again, the type property is purely for debugging.

  var _bracketL = {type: "[", beforeExpr: true}, _bracketR = {type: "]"}, _braceL = {type: "{", beforeExpr: true};
   var _braceR = {type: "}"}, _parenL = {type: "(", beforeExpr: true}, _parenR = {type: ")"};
   var _comma = {type: ",", beforeExpr: true}, _semi = {type: ";", beforeExpr: true};
   var _colon = {type: ":", beforeExpr: true}, _dot = {type: "."}, _ellipsis = {type: "..."}, _question = {type: "?", beforeExpr: true};
@@ -268,7 +272,7 @@ switch first dispatches on the lengths, to save on comparisons.

 
   var isEcma5AndLessKeyword = makePredicate(ecma5AndLessKeywords);
 
-  var isEcma6Keyword = makePredicate(ecma5AndLessKeywords + " let const class extends static of");
+  var isEcma6Keyword = makePredicate(ecma5AndLessKeywords + " let const class extends static of module export import from as");
 
   var isKeyword = isEcma5AndLessKeyword;

Character categories

                                                                                   
                                
               
Big ugly regular expressions that match characters in the
 whitespace, identifier, and identifier-start categories. These
@@ -909,7 +913,8 @@ complexity.
                                         case _while: return parseWhileStatement(node);
     case _with: return parseWithStatement(node);
     case _braceL: return parseBlock(); // no point creating a function for this
-    case _semi: return parseEmptyStatement(node);                                                                                   
                                
               
If the statement does not start with a statement keyword or a
+    case _semi: return parseEmptyStatement(node);
+    case _export: return parseExport(node);                                                                                   
                                
               
If the statement does not start with a statement keyword or a
 brace, it's an ExpressionStatement or LabeledStatement. We
 simply start parsing an expression, and afterwards, if the
 next token is a colon and the expression was a simple
@@ -1684,6 +1689,51 @@ if possible.
                                         <
   }                                                                                   
                                
               
Checks if node can be assignable spread argument.
                                         
  function checkSpreadAssign(node) {
     if (node.type !== "Identifier" && node.type !== "ArrayPattern")
       unexpected(node.start);
+  }
                                                                                   
                                
               
Parses module export declaration.
                                         
  function parseExport(node) {
+    next();
+    if (tokType === _var || tokType === _const || tokType === _let || tokType === _function || tokType === _class) {
+      node.declaration = parseStatement();
+      node.default = false;
+      node.specifiers = null;
+      node.source = null;
+    } else
+    if (eat(_default)) {
+      node.declaration = parseExpression(true);
+      node.default = true;
+      node.specifiers = null;
+      node.source = null;
+      semicolon();
+    } else
+    if (tokVal === '*') {
+      node.declaration = null;
+      node.default = false;
+      var specifier = startNode();
+      next();
+      node.specifiers = [finishNode(specifier, "ExportBatchSpecifier")];
+      expect(_from);
+      node.source = tokType === _string ? parseExprAtom() : unexpected();
+    } else
+    if (eat(_braceL)) {
+      node.declaration = null;
+      node.default = false;
+      node.specifiers = parseModuleSpecifiers("ExportSpecifier");
+      node.source = eat(_from) ? (tokType === _string ? parseExprAtom() : unexpected()) : null;
+    } else unexpected();
+    return finishNode(node, "ExportDeclaration");
+  }
                                                                                   
                                
               
Parses a comma-separated list of module imports/exports.
                                         
  function parseModuleSpecifiers(type) {
+    var nodes = [], first = true;
+    while (!eat(_braceR)) {
+      if (!first) {
+        expect(_comma);
+        if (options.allowTrailingCommas && eat(_braceR)) break;
+      } else first = false;
+
+      var node = startNode();
+      node.id = parseIdent();
+      node.name = eat(_as) ? parseIdent(true) : null;
+      nodes.push(finishNode(node, type));
+    }
+    return nodes;
   }
 
 });
diff --git a/test/tests-harmony.js b/test/tests-harmony.js
index f69ae66f52..eed92440bd 100644
--- a/test/tests-harmony.js
+++ b/test/tests-harmony.js
@@ -4965,6 +4965,7 @@ test("export var document", {
         end: {line: 1, column: 19}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 19],
@@ -5023,6 +5024,7 @@ test("export var document = { }", {
         end: {line: 1, column: 25}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 25],
@@ -5073,6 +5075,7 @@ test("export let document", {
         end: {line: 1, column: 19}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 19],
@@ -5131,6 +5134,7 @@ test("export let document = { }", {
         end: {line: 1, column: 25}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 25],
@@ -5189,6 +5193,7 @@ test("export const document = { }", {
         end: {line: 1, column: 27}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 27],
@@ -5243,6 +5248,7 @@ test("export function parse() { }", {
         end: {line: 1, column: 27}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 27],
@@ -5293,6 +5299,7 @@ test("export class Class {}", {
         end: {line: 1, column: 21}
       }
     },
+    default: false,
     specifiers: null,
     source: null,
     range: [0, 21],
@@ -5312,49 +5319,33 @@ test("export class Class {}", {
   locations: true
 });
 
-test("export default = 42", {
+test("export default 42", {
   type: "Program",
   body: [{
     type: "ExportDeclaration",
-    declaration: [{
-      type: "VariableDeclarator",
-      id: {
-        type: "Identifier",
-        name: "default",
-        range: [7, 14],
-        loc: {
-          start: {line: 1, column: 7},
-          end: {line: 1, column: 14}
-        }
-      },
-      init: {
-        type: "Literal",
-        value: 42,
-        raw: "42",
-        range: [17, 19],
-        loc: {
-          start: {line: 1, column: 17},
-          end: {line: 1, column: 19}
-        }
-      },
-      range: [7, 19],
+    declaration: {
+      type: "Literal",
+      value: 42,
+      raw: "42",
+      range: [15, 17],
       loc: {
-        start: {line: 1, column: 7},
-        end: {line: 1, column: 19}
+        start: {line: 1, column: 15},
+        end: {line: 1, column: 17}
       }
-    }],
+    },
+    default: true,
     specifiers: null,
     source: null,
-    range: [0, 19],
+    range: [0, 17],
     loc: {
       start: {line: 1, column: 0},
-      end: {line: 1, column: 19}
+      end: {line: 1, column: 17}
     }
   }],
-  range: [0, 19],
+  range: [0, 17],
   loc: {
     start: {line: 1, column: 0},
-    end: {line: 1, column: 19}
+    end: {line: 1, column: 17}
   }
 }, {
   ecmaVersion: 6,
@@ -5362,36 +5353,7 @@ test("export default = 42", {
   locations: true
 });
 
-test("export *", {
-  type: "Program",
-  body: [{
-    type: "ExportDeclaration",
-    declaration: null,
-    specifiers: [{
-      type: "ExportBatchSpecifier",
-      range: [7, 8],
-      loc: {
-        start: {line: 1, column: 7},
-        end: {line: 1, column: 8}
-      }
-    }],
-    source: null,
-    range: [0, 8],
-    loc: {
-      start: {line: 1, column: 0},
-      end: {line: 1, column: 8}
-    }
-  }],
-  range: [0, 8],
-  loc: {
-    start: {line: 1, column: 0},
-    end: {line: 1, column: 8}
-  }
-}, {
-  ecmaVersion: 6,
-  ranges: true,
-  locations: true
-});
+testFail("export *", "Unexpected token (1:8)", {ecmaVersion: 6});
 
 test("export * from \"crypto\"", {
   type: "Program",