2015-05-01 01:01:10 -04:00

410 lines
10 KiB
JavaScript

import detectIndent from "detect-indent";
import Whitespace from "./whitespace";
import repeating from "repeating";
import SourceMap from "./source-map";
import Position from "./position";
import * as messages from "../messages";
import Buffer from "./buffer";
import extend from "lodash/object/extend";
import each from "lodash/collection/each";
import n from "./node";
import * as t from "../types";
class CodeGenerator {
constructor(ast, opts, code) {
opts = opts || {};
this.comments = ast.comments || [];
this.tokens = ast.tokens || [];
this.format = CodeGenerator.normalizeOptions(code, opts, this.tokens);
this.opts = opts;
this.ast = ast;
this.whitespace = new Whitespace(this.tokens, this.comments, this.format);
this.position = new Position;
this.map = new SourceMap(this.position, opts, code);
this.buffer = new Buffer(this.position, this.format);
}
static normalizeOptions(code, opts, tokens) {
var style = " ";
if (code) {
var indent = detectIndent(code).indent;
if (indent && indent !== " ") style = indent;
}
var format = {
retainLines: opts.retainLines,
comments: opts.comments == null || opts.comments,
compact: opts.compact,
quotes: CodeGenerator.findCommonStringDelimiter(code, tokens),
indent: {
adjustMultilineComment: true,
style: style,
base: 0
}
};
if (format.compact === "auto") {
format.compact = code.length > 100000; // 100KB
if (format.compact) {
console.error("[BABEL] " + messages.get("codeGeneratorDeopt", opts.filename, "100KB"));
}
}
return format;
}
static findCommonStringDelimiter(code, tokens) {
var occurences = {
single: 0,
double: 0
};
var checked = 0;
for (var i = 0; i < tokens.length; i++) {
var token = tokens[i];
if (token.type.label !== "string") continue;
if (checked >= 3) continue;
var raw = code.slice(token.start, token.end);
if (raw[0] === "'") {
occurences.single++;
} else {
occurences.double++;
}
checked++;
}
if (occurences.single > occurences.double) {
return "single";
} else {
return "double";
}
}
static generators = {
templateLiterals: require("./generators/template-literals"),
comprehensions: require("./generators/comprehensions"),
expressions: require("./generators/expressions"),
statements: require("./generators/statements"),
classes: require("./generators/classes"),
methods: require("./generators/methods"),
modules: require("./generators/modules"),
types: require("./generators/types"),
flow: require("./generators/flow"),
base: require("./generators/base"),
jsx: require("./generators/jsx")
};
generate() {
var ast = this.ast;
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()
};
}
buildPrint(parent) {
var print = (node, opts) => {
return this.print(node, parent, opts);
};
print.sequence = (nodes, opts = {}) => {
opts.statement = true;
return this.printJoin(print, nodes, opts);
};
print.join = (nodes, opts) => {
return this.printJoin(print, nodes, opts);
};
print.list = function (items, opts = {}) {
if (opts.separator == null) opts.separator = ", ";
print.join(items, opts);
};
print.block = (node) => {
return this.printBlock(print, node);
};
print.indentOnComments = (node) => {
return this.printAndIndentOnComments(print, node);
};
return print;
}
catchUp(node, parent) {
// catch up to this nodes newline if we're behind
if (node.loc && this.format.retainLines && this.buffer.buf) {
var needsParens = false;
if (parent && this.position.line < node.loc.start.line && t.isTerminatorless(parent)) {
needsParens = true;
this._push("(");
}
while (this.position.line < node.loc.start.line) {
this._push("\n");
}
return needsParens;
}
return false;
}
print(node, parent, opts = {}) {
if (!node) return;
if (parent && parent._compact) {
node._compact = true;
}
var oldConcise = this.format.concise;
if (node._compact) {
this.format.concise = true;
}
var newline = (leading) => {
if (!opts.statement && !n.isUserWhitespacable(node, parent)) {
return;
}
var lines = 0;
if (node.start != null && !node._ignoreUserWhitespace) {
// user node
if (leading) {
lines = this.whitespace.getNewlinesBefore(node);
} else {
lines = this.whitespace.getNewlinesAfter(node);
}
} else {
// generated node
if (!leading) lines++; // always include at least a single line after
if (opts.addNewlines) lines += opts.addNewlines(leading, node) || 0;
var needs = n.needsWhitespaceAfter;
if (leading) needs = n.needsWhitespaceBefore;
if (needs(node, parent)) lines++;
// generated nodes can't add starting file whitespace
if (!this.buffer.buf) lines = 0;
}
this.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);
var needsParensFromCatchup = this.catchUp(node, parent);
newline(true);
if (opts.before) opts.before();
this.map.mark(node, "start");
this[node.type](node, this.buildPrint(node), parent);
if (needsNoLineTermParens) {
this.newline();
this.dedent();
}
if (needsParens || needsParensFromCatchup) this.push(")");
this.map.mark(node, "end");
if (opts.after) opts.after();
newline(false);
this.printTrailingComments(node, parent);
} else {
throw new ReferenceError(`unknown node of type ${JSON.stringify(node.type)} with constructor ${JSON.stringify(node && node.constructor.name)}`);
}
this.format.concise = oldConcise;
}
printJoin(print, nodes, opts = {}) {
if (!nodes || !nodes.length) return;
var len = nodes.length;
if (opts.indent) this.indent();
each(nodes, (node, i) => {
print(node, {
statement: opts.statement,
addNewlines: opts.addNewlines,
after: () => {
if (opts.iterator) {
opts.iterator(node, i);
}
if (opts.separator && i < len - 1) {
this.push(opts.separator);
}
}
});
});
if (opts.indent) this.dedent();
}
printAndIndentOnComments(print, node) {
var indent = !!node.leadingComments;
if (indent) this.indent();
print(node);
if (indent) this.dedent();
}
printBlock(print, node) {
if (t.isEmptyStatement(node)) {
this.semicolon();
} else {
this.push(" ");
print(node);
}
}
generateComment(comment) {
var val = comment.value;
if (comment.type === "Line") {
val = `//${val}`;
} else {
val = `/*${val}*/`;
}
return val;
}
printTrailingComments(node, parent) {
this._printComments(this.getComments("trailingComments", node, parent));
}
printLeadingComments(node, parent) {
this._printComments(this.getComments("leadingComments", node, parent));
}
getComments(key, node, parent) {
if (t.isExpressionStatement(parent)) {
return [];
}
var comments = [];
var nodes = [node];
if (t.isExpressionStatement(node)) {
nodes.push(node.argument);
}
each(nodes, (node) => {
comments = comments.concat(this._getComments(key, node));
});
return comments;
}
_getComments(key, node) {
return (node && node[key]) || [];
}
_printComments(comments) {
if (this.format.compact) return;
if (!this.format.comments) return;
if (!comments || !comments.length) return;
each(comments, (comment) => {
var skip = false;
// find the original comment in the ast and set it as displayed
each(this.ast.comments, function (origComment) {
if (origComment.start === comment.start) {
// comment has already been output
if (origComment._displayed) skip = true;
origComment._displayed = true;
return false;
}
});
if (skip) return;
this.catchUp(comment);
// whitespace before
this.newline(this.whitespace.getNewlinesBefore(comment));
var column = this.position.column;
var val = this.generateComment(comment);
if (column && !this.isLast(["\n", " ", "[", "{"])) {
this._push(" ");
column++;
}
//
if (comment.type === "Block" && this.format.indent.adjustMultilineComment) {
var offset = comment.loc.start.column;
if (offset) {
var newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
val = val.replace(newlineRegex, "\n");
}
var indent = Math.max(this.indentSize(), column);
val = val.replace(/\n/g, `\n${repeating(" ", indent)}`);
}
if (column === 0) {
val = this.getIndent() + val;
}
// force a newline for line comments when retainLines is set in case the next printed node
// doesn't catch up
if (this.format.retainLines && comment.type === "Line") {
val += "\n";
}
//
this._push(val);
// whitespace after
this.newline(this.whitespace.getNewlinesAfter(comment));
});
}
}
each(Buffer.prototype, function (fn, key) {
CodeGenerator.prototype[key] = function () {
return fn.apply(this.buffer, arguments);
};
});
each(CodeGenerator.generators, function (generator) {
extend(CodeGenerator.prototype, generator);
});
module.exports = function (ast, opts, code) {
var gen = new CodeGenerator(ast, opts, code);
return gen.generate();
};
module.exports.CodeGenerator = CodeGenerator;