Doodle3D-API/jspm_packages/npm/babel-core@5.6.20/lib/acorn/src/expression.js

842 lines
31 KiB
JavaScript

/* */
"format cjs";
"use strict";
var _babelToolsProtectJs2 = require("./../../babel/tools/protect.js");
var _babelToolsProtectJs3 = _interopRequireDefault(_babelToolsProtectJs2);
// A recursive descent parser operates by defining functions for all
// syntactic elements, and recursively calling those, each function
// advancing the input stream and returning an AST node. Precedence
// of constructs (for example, the fact that `!x[1]` means `!(x[1])`
// instead of `(!x)[1]` is handled by the fact that the parser
// function that parses unary prefix operators is called first, and
// in turn calls the function that parses `[]` subscripts — that
// way, it'll receive the node for `x[1]` already parsed, and wraps
// *that* in the unary operator node.
//
// Acorn uses an [operator precedence parser][opp] to handle binary
// operator precedence, because it is much more compact than using
// the technique outlined above, which uses different, nesting
// functions to specify precedence, for all of the ten binary
// precedence levels that JavaScript defines.
//
// [opp]: http://en.wikipedia.org/wiki/Operator-precedence_parser
var _tokentype = require("./tokentype");
var _state = require("./state");
var _identifier = require("./identifier");
var _util = require("./util");
_babelToolsProtectJs3["default"](module);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
var pp = _state.Parser.prototype;
// Check if property name clashes with already added.
// Object/class getters and setters are not allowed to clash —
// either with each other or with an init property — and in
// strict mode, init properties are also not allowed to be repeated.
pp.checkPropClash = function (prop, propHash) {
if (this.options.ecmaVersion >= 6 && (prop.computed || prop.method || prop.shorthand)) return;
var key = prop.key,
name = undefined;
switch (key.type) {
case "Identifier":
name = key.name;break;
case "Literal":
name = String(key.value);break;
default:
return;
}
var kind = prop.kind;
if (this.options.ecmaVersion >= 6) {
if (name === "__proto__" && kind === "init") {
if (propHash.proto) this.raise(key.start, "Redefinition of __proto__ property");
propHash.proto = true;
}
return;
}
var other = undefined;
if (_util.has(propHash, name)) {
other = propHash[name];
var isGetSet = kind !== "init";
if ((this.strict || isGetSet) && other[kind] || !(isGetSet ^ other.init)) this.raise(key.start, "Redefinition of property");
} else {
other = propHash[name] = {
init: false,
get: false,
set: false
};
}
other[kind] = true;
};
// ### Expression parsing
// These nest, from the most general expression type at the top to
// 'atomic', nondivisible expression types at the bottom. Most of
// the functions will simply let the function(s) below them parse,
// and, *if* the syntactic construct they handle is present, wrap
// the AST node that the inner parser gave them in another node.
// Parse a full expression. The optional arguments are used to
// forbid the `in` operator (in for loops initalization expressions)
// and provide reference for storing '=' operator inside shorthand
// property assignment in contexts where both object expression
// and object pattern might appear (so it's possible to raise
// delayed syntax error at correct position).
pp.parseExpression = function (noIn, refShorthandDefaultPos) {
var start = this.markPosition();
var expr = this.parseMaybeAssign(noIn, refShorthandDefaultPos);
if (this.type === _tokentype.types.comma) {
var node = this.startNodeAt(start);
node.expressions = [expr];
while (this.eat(_tokentype.types.comma)) node.expressions.push(this.parseMaybeAssign(noIn, refShorthandDefaultPos));
return this.finishNode(node, "SequenceExpression");
}
return expr;
};
// Parse an assignment expression. This includes applications of
// operators like `+=`.
pp.parseMaybeAssign = function (noIn, refShorthandDefaultPos, afterLeftParse) {
if (this.type == _tokentype.types._yield && this.inGenerator) return this.parseYield();
var failOnShorthandAssign = undefined;
if (!refShorthandDefaultPos) {
refShorthandDefaultPos = { start: 0 };
failOnShorthandAssign = true;
} else {
failOnShorthandAssign = false;
}
var start = this.markPosition();
if (this.type == _tokentype.types.parenL || this.type == _tokentype.types.name) this.potentialArrowAt = this.start;
var left = this.parseMaybeConditional(noIn, refShorthandDefaultPos);
if (afterLeftParse) left = afterLeftParse.call(this, left, start);
if (this.type.isAssign) {
var node = this.startNodeAt(start);
node.operator = this.value;
node.left = this.type === _tokentype.types.eq ? this.toAssignable(left) : left;
refShorthandDefaultPos.start = 0; // reset because shorthand default was used correctly
this.checkLVal(left);
if (left.parenthesizedExpression) {
var errorMsg = undefined;
if (left.type === "ObjectPattern") {
errorMsg = "`({a}) = 0` use `({a} = 0)`";
} else if (left.type === "ArrayPattern") {
errorMsg = "`([a]) = 0` use `([a] = 0)`";
}
if (errorMsg) {
this.raise(left.start, "You're trying to assign to a parenthesized expression, eg. instead of " + errorMsg);
}
}
this.next();
node.right = this.parseMaybeAssign(noIn);
return this.finishNode(node, "AssignmentExpression");
} else if (failOnShorthandAssign && refShorthandDefaultPos.start) {
this.unexpected(refShorthandDefaultPos.start);
}
return left;
};
// Parse a ternary conditional (`?:`) operator.
pp.parseMaybeConditional = function (noIn, refShorthandDefaultPos) {
var start = this.markPosition();
var expr = this.parseExprOps(noIn, refShorthandDefaultPos);
if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
if (this.eat(_tokentype.types.question)) {
var node = this.startNodeAt(start);
node.test = expr;
node.consequent = this.parseMaybeAssign();
this.expect(_tokentype.types.colon);
node.alternate = this.parseMaybeAssign(noIn);
return this.finishNode(node, "ConditionalExpression");
}
return expr;
};
// Start the precedence parser.
pp.parseExprOps = function (noIn, refShorthandDefaultPos) {
var start = this.markPosition();
var expr = this.parseMaybeUnary(refShorthandDefaultPos);
if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
return this.parseExprOp(expr, start, -1, noIn);
};
// Parse binary operators with the operator precedence parsing
// algorithm. `left` is the left-hand side of the operator.
// `minPrec` provides context that allows the function to stop and
// defer further parser to one of its callers when it encounters an
// operator that has a lower precedence than the set it is parsing.
pp.parseExprOp = function (left, leftStart, minPrec, noIn) {
var prec = this.type.binop;
if (prec != null && (!noIn || this.type !== _tokentype.types._in)) {
if (prec > minPrec) {
var node = this.startNodeAt(leftStart);
node.left = left;
node.operator = this.value;
var op = this.type;
this.next();
var start = this.markPosition();
node.right = this.parseExprOp(this.parseMaybeUnary(), start, op.rightAssociative ? prec - 1 : prec, noIn);
this.finishNode(node, op === _tokentype.types.logicalOR || op === _tokentype.types.logicalAND ? "LogicalExpression" : "BinaryExpression");
return this.parseExprOp(node, leftStart, minPrec, noIn);
}
}
return left;
};
// Parse unary operators, both prefix and postfix.
pp.parseMaybeUnary = function (refShorthandDefaultPos) {
if (this.type.prefix) {
var node = this.startNode(),
update = this.type === _tokentype.types.incDec;
node.operator = this.value;
node.prefix = true;
this.next();
node.argument = this.parseMaybeUnary();
if (refShorthandDefaultPos && refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start);
if (update) this.checkLVal(node.argument);else if (this.strict && node.operator === "delete" && node.argument.type === "Identifier") this.raise(node.start, "Deleting local variable in strict mode");
return this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
}
var start = this.markPosition();
var expr = this.parseExprSubscripts(refShorthandDefaultPos);
if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
while (this.type.postfix && !this.canInsertSemicolon()) {
var node = this.startNodeAt(start);
node.operator = this.value;
node.prefix = false;
node.argument = expr;
this.checkLVal(expr);
this.next();
expr = this.finishNode(node, "UpdateExpression");
}
return expr;
};
// Parse call, dot, and `[]`-subscript expressions.
pp.parseExprSubscripts = function (refShorthandDefaultPos) {
var start = this.markPosition();
var expr = this.parseExprAtom(refShorthandDefaultPos);
if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
return this.parseSubscripts(expr, start);
};
pp.parseSubscripts = function (base, start, noCalls) {
if (!noCalls && this.eat(_tokentype.types.doubleColon)) {
var node = this.startNodeAt(start);
node.object = base;
node.callee = this.parseNoCallExpr();
return this.parseSubscripts(this.finishNode(node, "BindExpression"), start, noCalls);
} else if (this.eat(_tokentype.types.dot)) {
var node = this.startNodeAt(start);
node.object = base;
node.property = this.parseIdent(true);
node.computed = false;
return this.parseSubscripts(this.finishNode(node, "MemberExpression"), start, noCalls);
} else if (this.eat(_tokentype.types.bracketL)) {
var node = this.startNodeAt(start);
node.object = base;
node.property = this.parseExpression();
node.computed = true;
this.expect(_tokentype.types.bracketR);
return this.parseSubscripts(this.finishNode(node, "MemberExpression"), start, noCalls);
} else if (!noCalls && this.eat(_tokentype.types.parenL)) {
var node = this.startNodeAt(start);
node.callee = base;
node.arguments = this.parseExprList(_tokentype.types.parenR, this.options.features["es7.trailingFunctionCommas"]);
return this.parseSubscripts(this.finishNode(node, "CallExpression"), start, noCalls);
} else if (this.type === _tokentype.types.backQuote) {
var node = this.startNodeAt(start);
node.tag = base;
node.quasi = this.parseTemplate();
return this.parseSubscripts(this.finishNode(node, "TaggedTemplateExpression"), start, noCalls);
}return base;
};
// Parse a no-call expression (like argument of `new` or `::` operators).
pp.parseNoCallExpr = function () {
var start = this.markPosition();
return this.parseSubscripts(this.parseExprAtom(), start, true);
};
// Parse an atomic expression — either a single token that is an
// expression, an expression started by a keyword like `function` or
// `new`, or an expression wrapped in punctuation like `()`, `[]`,
// or `{}`.
pp.parseExprAtom = function (refShorthandDefaultPos) {
var node = undefined,
canBeArrow = this.potentialArrowAt == this.start;
switch (this.type) {
case _tokentype.types._super:
if (!this.inFunction) this.raise(this.start, "'super' outside of function or class");
case _tokentype.types._this:
var type = this.type === _tokentype.types._this ? "ThisExpression" : "Super";
node = this.startNode();
this.next();
return this.finishNode(node, type);
case _tokentype.types._yield:
if (this.inGenerator) this.unexpected();
case _tokentype.types._do:
if (this.options.features["es7.doExpressions"]) {
var _node = this.startNode();
this.next();
var oldInFunction = this.inFunction;
var oldLabels = this.labels;
this.labels = [];
this.inFunction = false;
_node.body = this.parseBlock();
this.inFunction = oldInFunction;
this.labels = oldLabels;
return this.finishNode(_node, "DoExpression");
}
case _tokentype.types.name:
var start = this.markPosition();
node = this.startNode();
var id = this.parseIdent(this.type !== _tokentype.types.name);
//
if (this.options.features["es7.asyncFunctions"]) {
// async functions!
if (id.name === "async" && !this.canInsertSemicolon()) {
// arrow functions
if (this.type === _tokentype.types.parenL) {
var expr = this.parseParenAndDistinguishExpression(start, true, true);
if (expr && expr.type === "ArrowFunctionExpression") {
return expr;
} else {
node.callee = id;
if (!expr) {
node.arguments = [];
} else if (expr.type === "SequenceExpression") {
node.arguments = expr.expressions;
} else {
node.arguments = [expr];
}
return this.parseSubscripts(this.finishNode(node, "CallExpression"), start);
}
} else if (this.type === _tokentype.types.name) {
id = this.parseIdent();
this.expect(_tokentype.types.arrow);
return this.parseArrowExpression(node, [id], true);
}
// normal functions
if (this.type === _tokentype.types._function && !this.canInsertSemicolon()) {
this.next();
return this.parseFunction(node, false, false, true);
}
} else if (id.name === "await") {
if (this.inAsync) return this.parseAwait(node);
}
}
//
if (canBeArrow && !this.canInsertSemicolon() && this.eat(_tokentype.types.arrow)) return this.parseArrowExpression(this.startNodeAt(start), [id]);
return id;
case _tokentype.types.regexp:
var value = this.value;
node = this.parseLiteral(value.value);
node.regex = { pattern: value.pattern, flags: value.flags };
return node;
case _tokentype.types.num:case _tokentype.types.string:
return this.parseLiteral(this.value);
case _tokentype.types._null:case _tokentype.types._true:case _tokentype.types._false:
node = this.startNode();
node.value = this.type === _tokentype.types._null ? null : this.type === _tokentype.types._true;
node.raw = this.type.keyword;
this.next();
return this.finishNode(node, "Literal");
case _tokentype.types.parenL:
return this.parseParenAndDistinguishExpression(null, null, canBeArrow);
case _tokentype.types.bracketL:
node = this.startNode();
this.next();
// check whether this is array comprehension or regular array
if ((this.options.ecmaVersion >= 7 || this.options.features["es7.comprehensions"]) && this.type === _tokentype.types._for) {
return this.parseComprehension(node, false);
}
node.elements = this.parseExprList(_tokentype.types.bracketR, true, true, refShorthandDefaultPos);
return this.finishNode(node, "ArrayExpression");
case _tokentype.types.braceL:
return this.parseObj(false, refShorthandDefaultPos);
case _tokentype.types._function:
node = this.startNode();
this.next();
return this.parseFunction(node, false);
case _tokentype.types.at:
this.parseDecorators();
case _tokentype.types._class:
node = this.startNode();
this.takeDecorators(node);
return this.parseClass(node, false);
case _tokentype.types._new:
return this.parseNew();
case _tokentype.types.backQuote:
return this.parseTemplate();
case _tokentype.types.doubleColon:
node = this.startNode();
this.next();
node.object = null;
var callee = node.callee = this.parseNoCallExpr();
if (callee.type !== "MemberExpression") this.raise(callee.start, "Binding should be performed on object property.");
return this.finishNode(node, "BindExpression");
default:
this.unexpected();
}
};
pp.parseLiteral = function (value) {
var node = this.startNode();
node.value = value;
node.raw = this.input.slice(this.start, this.end);
this.next();
return this.finishNode(node, "Literal");
};
pp.parseParenExpression = function () {
this.expect(_tokentype.types.parenL);
var val = this.parseExpression();
this.expect(_tokentype.types.parenR);
return val;
};
pp.parseParenAndDistinguishExpression = function (start, isAsync, canBeArrow) {
start = start || this.markPosition();
var val = undefined;
if (this.options.ecmaVersion >= 6) {
this.next();
if ((this.options.features["es7.comprehensions"] || this.options.ecmaVersion >= 7) && this.type === _tokentype.types._for) {
return this.parseComprehension(this.startNodeAt(start), true);
}
var innerStart = this.markPosition(),
exprList = [],
first = true;
var refShorthandDefaultPos = { start: 0 },
spreadStart = undefined,
innerParenStart = undefined,
optionalCommaStart = undefined;
while (this.type !== _tokentype.types.parenR) {
if (first) {
first = false;
} else {
this.expect(_tokentype.types.comma);
if (this.type === _tokentype.types.parenR && this.options.features["es7.trailingFunctionCommas"]) {
optionalCommaStart = this.start;
break;
}
}
if (this.type === _tokentype.types.ellipsis) {
var spreadNodeStart = this.markPosition();
spreadStart = this.start;
exprList.push(this.parseParenItem(this.parseRest(), spreadNodeStart));
break;
} else {
if (this.type === _tokentype.types.parenL && !innerParenStart) {
innerParenStart = this.start;
}
exprList.push(this.parseMaybeAssign(false, refShorthandDefaultPos, this.parseParenItem));
}
}
var innerEnd = this.markPosition();
this.expect(_tokentype.types.parenR);
if (canBeArrow && !this.canInsertSemicolon() && this.eat(_tokentype.types.arrow)) {
if (innerParenStart) this.unexpected(innerParenStart);
return this.parseParenArrowList(start, exprList, isAsync);
}
if (!exprList.length) {
if (isAsync) {
return;
} else {
this.unexpected(this.lastTokStart);
}
}
if (optionalCommaStart) this.unexpected(optionalCommaStart);
if (spreadStart) this.unexpected(spreadStart);
if (refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start);
if (exprList.length > 1) {
val = this.startNodeAt(innerStart);
val.expressions = exprList;
this.finishNodeAt(val, "SequenceExpression", innerEnd);
} else {
val = exprList[0];
}
} else {
val = this.parseParenExpression();
}
if (this.options.preserveParens) {
var par = this.startNodeAt(start);
par.expression = val;
return this.finishNode(par, "ParenthesizedExpression");
} else {
val.parenthesizedExpression = true;
return val;
}
};
pp.parseParenArrowList = function (start, exprList, isAsync) {
return this.parseArrowExpression(this.startNodeAt(start), exprList, isAsync);
};
pp.parseParenItem = function (node, start) {
return node;
};
// New's precedence is slightly tricky. It must allow its argument
// to be a `[]` or dot subscript expression, but not a call — at
// least, not without wrapping it in parentheses. Thus, it uses the
var empty = [];
pp.parseNew = function () {
var node = this.startNode();
var meta = this.parseIdent(true);
if (this.options.ecmaVersion >= 6 && this.eat(_tokentype.types.dot)) {
node.meta = meta;
node.property = this.parseIdent(true);
if (node.property.name !== "target") this.raise(node.property.start, "The only valid meta property for new is new.target");
return this.finishNode(node, "MetaProperty");
}
node.callee = this.parseNoCallExpr();
if (this.eat(_tokentype.types.parenL)) node.arguments = this.parseExprList(_tokentype.types.parenR, this.options.features["es7.trailingFunctionCommas"]);else node.arguments = empty;
return this.finishNode(node, "NewExpression");
};
// Parse template expression.
pp.parseTemplateElement = function () {
var elem = this.startNode();
elem.value = {
raw: this.input.slice(this.start, this.end).replace(/\r\n?/g, "\n"),
cooked: this.value
};
this.next();
elem.tail = this.type === _tokentype.types.backQuote;
return this.finishNode(elem, "TemplateElement");
};
pp.parseTemplate = function () {
var node = this.startNode();
this.next();
node.expressions = [];
var curElt = this.parseTemplateElement();
node.quasis = [curElt];
while (!curElt.tail) {
this.expect(_tokentype.types.dollarBraceL);
node.expressions.push(this.parseExpression());
this.expect(_tokentype.types.braceR);
node.quasis.push(curElt = this.parseTemplateElement());
}
this.next();
return this.finishNode(node, "TemplateLiteral");
};
// Parse an object literal or binding pattern.
pp.parseObj = function (isPattern, refShorthandDefaultPos) {
var node = this.startNode(),
first = true,
propHash = {};
node.properties = [];
var decorators = [];
this.next();
while (!this.eat(_tokentype.types.braceR)) {
if (!first) {
this.expect(_tokentype.types.comma);
if (this.afterTrailingComma(_tokentype.types.braceR)) break;
} else first = false;
while (this.type === _tokentype.types.at) {
decorators.push(this.parseDecorator());
}
var prop = this.startNode(),
isGenerator = false,
isAsync = false,
start = undefined;
if (decorators.length) {
prop.decorators = decorators;
decorators = [];
}
if (this.options.features["es7.objectRestSpread"] && this.type === _tokentype.types.ellipsis) {
prop = this.parseSpread();
prop.type = "SpreadProperty";
node.properties.push(prop);
continue;
}
if (this.options.ecmaVersion >= 6) {
prop.method = false;
prop.shorthand = false;
if (isPattern || refShorthandDefaultPos) start = this.markPosition();
if (!isPattern) isGenerator = this.eat(_tokentype.types.star);
}
if (this.options.features["es7.asyncFunctions"] && this.isContextual("async")) {
if (isGenerator || isPattern) this.unexpected();
var asyncId = this.parseIdent();
if (this.type === _tokentype.types.colon || this.type === _tokentype.types.parenL) {
prop.key = asyncId;
} else {
isAsync = true;
this.parsePropertyName(prop);
}
} else {
this.parsePropertyName(prop);
}
this.parseObjPropValue(prop, start, isGenerator, isAsync, isPattern, refShorthandDefaultPos);
this.checkPropClash(prop, propHash);
node.properties.push(this.finishNode(prop, "Property"));
}
if (decorators.length) {
this.raise(this.start, "You have trailing decorators with no property");
}
return this.finishNode(node, isPattern ? "ObjectPattern" : "ObjectExpression");
};
pp.parseObjPropValue = function (prop, start, isGenerator, isAsync, isPattern, refShorthandDefaultPos) {
if (this.eat(_tokentype.types.colon)) {
prop.value = isPattern ? this.parseMaybeDefault() : this.parseMaybeAssign(false, refShorthandDefaultPos);
prop.kind = "init";
} else if (this.options.ecmaVersion >= 6 && this.type === _tokentype.types.parenL) {
if (isPattern) this.unexpected();
prop.kind = "init";
prop.method = true;
prop.value = this.parseMethod(isGenerator, isAsync);
} else if (this.options.ecmaVersion >= 5 && !prop.computed && prop.key.type === "Identifier" && (prop.key.name === "get" || prop.key.name === "set") && (this.type != _tokentype.types.comma && this.type != _tokentype.types.braceR)) {
if (isGenerator || isAsync || isPattern) this.unexpected();
prop.kind = prop.key.name;
this.parsePropertyName(prop);
prop.value = this.parseMethod(false);
var paramCount = prop.kind === "get" ? 0 : 1;
if (prop.value.params.length !== paramCount) {
var _start = prop.value.start;
if (prop.kind === "get") this.raise(_start, "getter should have no params");else this.raise(_start, "setter should have exactly one param");
}
} else if (this.options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
prop.kind = "init";
if (isPattern) {
if (this.isKeyword(prop.key.name) || this.strict && (_identifier.reservedWords.strictBind(prop.key.name) || _identifier.reservedWords.strict(prop.key.name)) || !this.options.allowReserved && this.isReservedWord(prop.key.name)) this.raise(prop.key.start, "Binding " + prop.key.name);
prop.value = this.parseMaybeDefault(start, prop.key);
} else if (this.type === _tokentype.types.eq && refShorthandDefaultPos) {
if (!refShorthandDefaultPos.start) refShorthandDefaultPos.start = this.start;
prop.value = this.parseMaybeDefault(start, prop.key);
} else {
prop.value = prop.key;
}
prop.shorthand = true;
} else this.unexpected();
};
pp.parsePropertyName = function (prop) {
if (this.options.ecmaVersion >= 6) {
if (this.eat(_tokentype.types.bracketL)) {
prop.computed = true;
prop.key = this.parseMaybeAssign();
this.expect(_tokentype.types.bracketR);
return prop.key;
} else {
prop.computed = false;
}
}
return prop.key = this.type === _tokentype.types.num || this.type === _tokentype.types.string ? this.parseExprAtom() : this.parseIdent(true);
};
// Initialize empty function node.
pp.initFunction = function (node, isAsync) {
node.id = null;
if (this.options.ecmaVersion >= 6) {
node.generator = false;
node.expression = false;
}
if (this.options.features["es7.asyncFunctions"]) {
node.async = !!isAsync;
}
};
// Parse object or class method.
pp.parseMethod = function (isGenerator, isAsync) {
var node = this.startNode();
this.initFunction(node, isAsync);
this.expect(_tokentype.types.parenL);
node.params = this.parseBindingList(_tokentype.types.parenR, false, this.options.features["es7.trailingFunctionCommas"]);
if (this.options.ecmaVersion >= 6) {
node.generator = isGenerator;
}
this.parseFunctionBody(node);
return this.finishNode(node, "FunctionExpression");
};
// Parse arrow function expression with given parameters.
pp.parseArrowExpression = function (node, params, isAsync) {
this.initFunction(node, isAsync);
node.params = this.toAssignableList(params, true);
this.parseFunctionBody(node, true);
return this.finishNode(node, "ArrowFunctionExpression");
};
// Parse function body and check parameters.
pp.parseFunctionBody = function (node, allowExpression) {
var isExpression = allowExpression && this.type !== _tokentype.types.braceL;
var oldInAsync = this.inAsync;
this.inAsync = node.async;
if (isExpression) {
node.body = this.parseMaybeAssign();
node.expression = true;
} else {
// Start a new scope with regard to labels and the `inFunction`
// flag (restore them to their old value afterwards).
var oldInFunc = this.inFunction,
oldInGen = this.inGenerator,
oldLabels = this.labels;
this.inFunction = true;this.inGenerator = node.generator;this.labels = [];
node.body = this.parseBlock(true);
node.expression = false;
this.inFunction = oldInFunc;this.inGenerator = oldInGen;this.labels = oldLabels;
}
this.inAsync = oldInAsync;
// If this is a strict mode function, verify that argument names
// are not repeated, and it does not try to bind the words `eval`
// or `arguments`.
if (this.strict || !isExpression && node.body.body.length && this.isUseStrict(node.body.body[0])) {
var nameHash = {},
oldStrict = this.strict;
this.strict = true;
if (node.id) this.checkLVal(node.id, true);
for (var i = 0; i < node.params.length; i++) {
this.checkLVal(node.params[i], true, nameHash);
}this.strict = oldStrict;
}
};
// Parses a comma-separated list of expressions, and returns them as
// an array. `close` is the token type that ends the list, and
// `allowEmpty` can be turned on to allow subsequent commas with
// nothing in between them to be parsed as `null` (which is needed
// for array literals).
pp.parseExprList = function (close, allowTrailingComma, allowEmpty, refShorthandDefaultPos) {
var elts = [],
first = true;
while (!this.eat(close)) {
if (!first) {
this.expect(_tokentype.types.comma);
if (allowTrailingComma && this.afterTrailingComma(close)) break;
} else first = false;
if (allowEmpty && this.type === _tokentype.types.comma) {
elts.push(null);
} else {
if (this.type === _tokentype.types.ellipsis) elts.push(this.parseSpread(refShorthandDefaultPos));else elts.push(this.parseMaybeAssign(false, refShorthandDefaultPos));
}
}
return elts;
};
// Parse the next token as an identifier. If `liberal` is true (used
// when parsing properties), it will also convert keywords into
// identifiers.
pp.parseIdent = function (liberal) {
var node = this.startNode();
if (liberal && this.options.allowReserved == "never") liberal = false;
if (this.type === _tokentype.types.name) {
if (!liberal && (!this.options.allowReserved && this.isReservedWord(this.value) || this.strict && _identifier.reservedWords.strict(this.value) && (this.options.ecmaVersion >= 6 || this.input.slice(this.start, this.end).indexOf("\\") == -1))) this.raise(this.start, "The keyword '" + this.value + "' is reserved");
node.name = this.value;
} else if (liberal && this.type.keyword) {
node.name = this.type.keyword;
} else {
this.unexpected();
}
this.next();
return this.finishNode(node, "Identifier");
};
// Parses await expression inside async function.
pp.parseAwait = function (node) {
if (this.eat(_tokentype.types.semi) || this.canInsertSemicolon()) {
this.unexpected();
}
node.all = this.eat(_tokentype.types.star);
node.argument = this.parseMaybeUnary();
return this.finishNode(node, "AwaitExpression");
};
// Parses yield expression inside generator.
pp.parseYield = function () {
var node = this.startNode();
this.next();
if (this.type == _tokentype.types.semi || this.canInsertSemicolon() || this.type != _tokentype.types.star && !this.type.startsExpr) {
node.delegate = false;
node.argument = null;
} else {
node.delegate = this.eat(_tokentype.types.star);
node.argument = this.parseMaybeAssign();
}
return this.finishNode(node, "YieldExpression");
};
// Parses array and generator comprehensions.
pp.parseComprehension = function (node, isGenerator) {
node.blocks = [];
while (this.type === _tokentype.types._for) {
var block = this.startNode();
this.next();
this.expect(_tokentype.types.parenL);
block.left = this.parseBindingAtom();
this.checkLVal(block.left, true);
this.expectContextual("of");
block.right = this.parseExpression();
this.expect(_tokentype.types.parenR);
node.blocks.push(this.finishNode(block, "ComprehensionBlock"));
}
node.filter = this.eat(_tokentype.types._if) ? this.parseParenExpression() : null;
node.body = this.parseExpression();
this.expect(isGenerator ? _tokentype.types.parenR : _tokentype.types.bracketR);
node.generator = isGenerator;
return this.finishNode(node, "ComprehensionExpression");
};