1124 lines
37 KiB
JavaScript
1124 lines
37 KiB
JavaScript
/* eslint max-len: 0 */
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// A recursive descent parser operates by defining functions for all
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// syntactic elements, and recursively calling those, each function
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// advancing the input stream and returning an AST node. Precedence
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// of constructs (for example, the fact that `!x[1]` means `!(x[1])`
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// instead of `(!x)[1]` is handled by the fact that the parser
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// function that parses unary prefix operators is called first, and
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// in turn calls the function that parses `[]` subscripts — that
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// way, it'll receive the node for `x[1]` already parsed, and wraps
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// *that* in the unary operator node.
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//
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// Acorn uses an [operator precedence parser][opp] to handle binary
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// operator precedence, because it is much more compact than using
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// the technique outlined above, which uses different, nesting
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// functions to specify precedence, for all of the ten binary
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// precedence levels that JavaScript defines.
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//
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// [opp]: http://en.wikipedia.org/wiki/Operator-precedence_parser
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import { types as tt } from "../tokenizer/types";
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import LValParser from "./lval";
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import { reservedWords } from "../util/identifier";
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export default class ExpressionParser extends LValParser {
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// Check if property name clashes with already added.
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// Object/class getters and setters are not allowed to clash —
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// either with each other or with an init property — and in
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// strict mode, init properties are also not allowed to be repeated.
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checkPropClash(prop, propHash) {
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if (prop.computed || prop.kind) return;
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const key = prop.key;
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// It is either an Identifier or a String/NumericLiteral
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const name = key.type === "Identifier" ? key.name : String(key.value);
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if (name === "__proto__") {
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if (propHash.proto) this.raise(key.start, "Redefinition of __proto__ property");
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propHash.proto = true;
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}
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}
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// Convenience method to parse an Expression only
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getExpression() {
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this.nextToken();
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const expr = this.parseExpression();
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if (!this.match(tt.eof)) {
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this.unexpected();
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}
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return expr;
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}
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// ### Expression parsing
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// These nest, from the most general expression type at the top to
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// 'atomic', nondivisible expression types at the bottom. Most of
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// the functions will simply let the function (s) below them parse,
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// and, *if* the syntactic construct they handle is present, wrap
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// the AST node that the inner parser gave them in another node.
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// Parse a full expression. The optional arguments are used to
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// forbid the `in` operator (in for loops initialization expressions)
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// and provide reference for storing '=' operator inside shorthand
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// property assignment in contexts where both object expression
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// and object pattern might appear (so it's possible to raise
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// delayed syntax error at correct position).
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parseExpression(noIn, refShorthandDefaultPos) {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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const expr = this.parseMaybeAssign(noIn, refShorthandDefaultPos);
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if (this.match(tt.comma)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.expressions = [expr];
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while (this.eat(tt.comma)) {
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node.expressions.push(this.parseMaybeAssign(noIn, refShorthandDefaultPos));
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}
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this.toReferencedList(node.expressions);
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return this.finishNode(node, "SequenceExpression");
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}
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return expr;
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}
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// Parse an assignment expression. This includes applications of
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// operators like `+=`.
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parseMaybeAssign(noIn, refShorthandDefaultPos, afterLeftParse, refNeedsArrowPos) {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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if (this.match(tt._yield) && this.state.inGenerator) {
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let left = this.parseYield();
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if (afterLeftParse) left = afterLeftParse.call(this, left, startPos, startLoc);
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return left;
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}
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let failOnShorthandAssign;
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if (refShorthandDefaultPos) {
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failOnShorthandAssign = false;
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} else {
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refShorthandDefaultPos = { start: 0 };
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failOnShorthandAssign = true;
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}
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if (this.match(tt.parenL) || this.match(tt.name)) {
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this.state.potentialArrowAt = this.state.start;
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}
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let left = this.parseMaybeConditional(noIn, refShorthandDefaultPos, refNeedsArrowPos);
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if (afterLeftParse) left = afterLeftParse.call(this, left, startPos, startLoc);
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if (this.state.type.isAssign) {
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const node = this.startNodeAt(startPos, startLoc);
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node.operator = this.state.value;
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node.left = this.match(tt.eq) ? this.toAssignable(left, undefined, "assignment expression") : left;
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refShorthandDefaultPos.start = 0; // reset because shorthand default was used correctly
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this.checkLVal(left, undefined, undefined, "assignment expression");
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if (left.extra && left.extra.parenthesized) {
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let errorMsg;
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if (left.type === "ObjectPattern") {
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errorMsg = "`({a}) = 0` use `({a} = 0)`";
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} else if (left.type === "ArrayPattern") {
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errorMsg = "`([a]) = 0` use `([a] = 0)`";
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}
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if (errorMsg) {
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this.raise(left.start, `You're trying to assign to a parenthesized expression, eg. instead of ${errorMsg}`);
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}
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}
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this.next();
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node.right = this.parseMaybeAssign(noIn);
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return this.finishNode(node, "AssignmentExpression");
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} else if (failOnShorthandAssign && refShorthandDefaultPos.start) {
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this.unexpected(refShorthandDefaultPos.start);
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}
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return left;
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}
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// Parse a ternary conditional (`?:`) operator.
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parseMaybeConditional(noIn, refShorthandDefaultPos, refNeedsArrowPos) {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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const expr = this.parseExprOps(noIn, refShorthandDefaultPos);
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if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
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return this.parseConditional(expr, noIn, startPos, startLoc, refNeedsArrowPos);
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}
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parseConditional(expr, noIn, startPos, startLoc) {
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if (this.eat(tt.question)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.test = expr;
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node.consequent = this.parseMaybeAssign();
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this.expect(tt.colon);
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node.alternate = this.parseMaybeAssign(noIn);
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return this.finishNode(node, "ConditionalExpression");
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}
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return expr;
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}
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// Start the precedence parser.
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parseExprOps(noIn, refShorthandDefaultPos) {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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const expr = this.parseMaybeUnary(refShorthandDefaultPos);
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if (refShorthandDefaultPos && refShorthandDefaultPos.start) {
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return expr;
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} else {
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return this.parseExprOp(expr, startPos, startLoc, -1, noIn);
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}
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}
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// Parse binary operators with the operator precedence parsing
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// algorithm. `left` is the left-hand side of the operator.
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// `minPrec` provides context that allows the function to stop and
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// defer further parser to one of its callers when it encounters an
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// operator that has a lower precedence than the set it is parsing.
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parseExprOp(left, leftStartPos, leftStartLoc, minPrec, noIn) {
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const prec = this.state.type.binop;
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if (prec != null && (!noIn || !this.match(tt._in))) {
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if (prec > minPrec) {
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const node = this.startNodeAt(leftStartPos, leftStartLoc);
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node.left = left;
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node.operator = this.state.value;
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if (
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node.operator === "**" &&
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left.type === "UnaryExpression" &&
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left.extra &&
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!left.extra.parenthesizedArgument &&
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!left.extra.parenthesized
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) {
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this.raise(left.argument.start, "Illegal expression. Wrap left hand side or entire exponentiation in parentheses.");
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}
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const op = this.state.type;
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this.next();
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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node.right = this.parseExprOp(this.parseMaybeUnary(), startPos, startLoc, op.rightAssociative ? prec - 1 : prec, noIn);
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this.finishNode(node, (op === tt.logicalOR || op === tt.logicalAND) ? "LogicalExpression" : "BinaryExpression");
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return this.parseExprOp(node, leftStartPos, leftStartLoc, minPrec, noIn);
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}
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}
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return left;
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}
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// Parse unary operators, both prefix and postfix.
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parseMaybeUnary(refShorthandDefaultPos) {
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if (this.state.type.prefix) {
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const node = this.startNode();
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const update = this.match(tt.incDec);
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node.operator = this.state.value;
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node.prefix = true;
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this.next();
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const argType = this.state.type;
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node.argument = this.parseMaybeUnary();
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this.addExtra(node, "parenthesizedArgument", argType === tt.parenL && (!node.argument.extra || !node.argument.extra.parenthesized));
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if (refShorthandDefaultPos && refShorthandDefaultPos.start) {
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this.unexpected(refShorthandDefaultPos.start);
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}
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if (update) {
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this.checkLVal(node.argument, undefined, undefined, "prefix operation");
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} else if (this.state.strict && node.operator === "delete" && node.argument.type === "Identifier") {
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this.raise(node.start, "Deleting local variable in strict mode");
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}
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return this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
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}
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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let expr = this.parseExprSubscripts(refShorthandDefaultPos);
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if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
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while (this.state.type.postfix && !this.canInsertSemicolon()) {
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const node = this.startNodeAt(startPos, startLoc);
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node.operator = this.state.value;
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node.prefix = false;
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node.argument = expr;
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this.checkLVal(expr, undefined, undefined, "postfix operation");
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this.next();
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expr = this.finishNode(node, "UpdateExpression");
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}
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return expr;
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}
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// Parse call, dot, and `[]`-subscript expressions.
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parseExprSubscripts(refShorthandDefaultPos) {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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const potentialArrowAt = this.state.potentialArrowAt;
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const expr = this.parseExprAtom(refShorthandDefaultPos);
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if (expr.type === "ArrowFunctionExpression" && expr.start === potentialArrowAt) {
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return expr;
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}
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if (refShorthandDefaultPos && refShorthandDefaultPos.start) {
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return expr;
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}
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return this.parseSubscripts(expr, startPos, startLoc);
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}
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parseSubscripts(base, startPos, startLoc, noCalls) {
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for (;;) {
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if (!noCalls && this.eat(tt.doubleColon)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.object = base;
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node.callee = this.parseNoCallExpr();
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return this.parseSubscripts(this.finishNode(node, "BindExpression"), startPos, startLoc, noCalls);
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} else if (this.eat(tt.dot)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.object = base;
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node.property = this.parseIdentifier(true);
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node.computed = false;
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base = this.finishNode(node, "MemberExpression");
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} else if (this.eat(tt.bracketL)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.object = base;
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node.property = this.parseExpression();
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node.computed = true;
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this.expect(tt.bracketR);
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base = this.finishNode(node, "MemberExpression");
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} else if (!noCalls && this.match(tt.parenL)) {
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const possibleAsync = this.state.potentialArrowAt === base.start && base.type === "Identifier" && base.name === "async" && !this.canInsertSemicolon();
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this.next();
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const node = this.startNodeAt(startPos, startLoc);
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node.callee = base;
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node.arguments = this.parseCallExpressionArguments(tt.parenR, possibleAsync);
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if (node.callee.type === "Import" && node.arguments.length !== 1) {
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this.raise(node.start, "import() requires exactly one argument");
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}
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base = this.finishNode(node, "CallExpression");
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if (possibleAsync && this.shouldParseAsyncArrow()) {
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return this.parseAsyncArrowFromCallExpression(this.startNodeAt(startPos, startLoc), node);
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} else {
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this.toReferencedList(node.arguments);
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}
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} else if (this.match(tt.backQuote)) {
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const node = this.startNodeAt(startPos, startLoc);
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node.tag = base;
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node.quasi = this.parseTemplate(true);
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base = this.finishNode(node, "TaggedTemplateExpression");
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} else {
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return base;
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}
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}
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}
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parseCallExpressionArguments(close, possibleAsyncArrow) {
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const elts = [];
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let innerParenStart;
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let first = true;
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while (!this.eat(close)) {
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if (first) {
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first = false;
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} else {
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this.expect(tt.comma);
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if (this.eat(close)) break;
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}
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// we need to make sure that if this is an async arrow functions, that we don't allow inner parens inside the params
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if (this.match(tt.parenL) && !innerParenStart) {
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innerParenStart = this.state.start;
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}
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elts.push(this.parseExprListItem(false, possibleAsyncArrow ? { start: 0 } : undefined, possibleAsyncArrow ? { start: 0 } : undefined));
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}
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// we found an async arrow function so let's not allow any inner parens
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if (possibleAsyncArrow && innerParenStart && this.shouldParseAsyncArrow()) {
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this.unexpected();
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}
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return elts;
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}
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shouldParseAsyncArrow() {
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return this.match(tt.arrow);
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}
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parseAsyncArrowFromCallExpression(node, call) {
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this.expect(tt.arrow);
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return this.parseArrowExpression(node, call.arguments, true);
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}
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// Parse a no-call expression (like argument of `new` or `::` operators).
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parseNoCallExpr() {
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const startPos = this.state.start;
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const startLoc = this.state.startLoc;
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return this.parseSubscripts(this.parseExprAtom(), startPos, startLoc, true);
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}
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// Parse an atomic expression — either a single token that is an
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// expression, an expression started by a keyword like `function` or
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// `new`, or an expression wrapped in punctuation like `()`, `[]`,
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// or `{}`.
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parseExprAtom(refShorthandDefaultPos) {
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const canBeArrow = this.state.potentialArrowAt === this.state.start;
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let node;
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switch (this.state.type) {
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case tt._super:
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if (!this.state.inMethod && !this.options.allowSuperOutsideMethod) {
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this.raise(this.state.start, "'super' outside of function or class");
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}
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node = this.startNode();
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this.next();
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if (!this.match(tt.parenL) && !this.match(tt.bracketL) && !this.match(tt.dot)) {
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this.unexpected();
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}
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if (this.match(tt.parenL) && this.state.inMethod !== "constructor" && !this.options.allowSuperOutsideMethod) {
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this.raise(node.start, "super() is only valid inside a class constructor. Make sure the method name is spelled exactly as 'constructor'.");
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}
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return this.finishNode(node, "Super");
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case tt._import:
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if (!this.hasPlugin("dynamicImport")) this.unexpected();
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node = this.startNode();
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this.next();
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if (!this.match(tt.parenL)) {
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this.unexpected(null, tt.parenL);
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}
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return this.finishNode(node, "Import");
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case tt._this:
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node = this.startNode();
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this.next();
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return this.finishNode(node, "ThisExpression");
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case tt._yield:
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if (this.state.inGenerator) this.unexpected();
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case tt.name:
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node = this.startNode();
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const allowAwait = this.state.value === "await" && this.state.inAsync;
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const allowYield = this.shouldAllowYieldIdentifier();
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const id = this.parseIdentifier(allowAwait || allowYield);
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if (id.name === "await") {
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if (this.state.inAsync || this.inModule) {
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return this.parseAwait(node);
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}
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} else if (id.name === "async" && this.match(tt._function) && !this.canInsertSemicolon()) {
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this.next();
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return this.parseFunction(node, false, false, true);
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} else if (canBeArrow && id.name === "async" && this.match(tt.name)) {
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const params = [this.parseIdentifier()];
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this.expect(tt.arrow);
|
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// let foo = bar => {};
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return this.parseArrowExpression(node, params, true);
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}
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if (canBeArrow && !this.canInsertSemicolon() && this.eat(tt.arrow)) {
|
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return this.parseArrowExpression(node, [id]);
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}
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return id;
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case tt._do:
|
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if (this.hasPlugin("doExpressions")) {
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const node = this.startNode();
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this.next();
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const oldInFunction = this.state.inFunction;
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const oldLabels = this.state.labels;
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this.state.labels = [];
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this.state.inFunction = false;
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node.body = this.parseBlock(false, true);
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this.state.inFunction = oldInFunction;
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this.state.labels = oldLabels;
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return this.finishNode(node, "DoExpression");
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}
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|
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case tt.regexp:
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const value = this.state.value;
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node = this.parseLiteral(value.value, "RegExpLiteral");
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node.pattern = value.pattern;
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node.flags = value.flags;
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return node;
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|
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case tt.num:
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return this.parseLiteral(this.state.value, "NumericLiteral");
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case tt.string:
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return this.parseLiteral(this.state.value, "StringLiteral");
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case tt._null:
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node = this.startNode();
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this.next();
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return this.finishNode(node, "NullLiteral");
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|
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case tt._true: case tt._false:
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node = this.startNode();
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node.value = this.match(tt._true);
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this.next();
|
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return this.finishNode(node, "BooleanLiteral");
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|
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case tt.parenL:
|
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return this.parseParenAndDistinguishExpression(null, null, canBeArrow);
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|
|
case tt.bracketL:
|
|
node = this.startNode();
|
|
this.next();
|
|
node.elements = this.parseExprList(tt.bracketR, true, refShorthandDefaultPos);
|
|
this.toReferencedList(node.elements);
|
|
return this.finishNode(node, "ArrayExpression");
|
|
|
|
case tt.braceL:
|
|
return this.parseObj(false, refShorthandDefaultPos);
|
|
|
|
case tt._function:
|
|
return this.parseFunctionExpression();
|
|
|
|
case tt.at:
|
|
this.parseDecorators();
|
|
|
|
case tt._class:
|
|
node = this.startNode();
|
|
this.takeDecorators(node);
|
|
return this.parseClass(node, false);
|
|
|
|
case tt._new:
|
|
return this.parseNew();
|
|
|
|
case tt.backQuote:
|
|
return this.parseTemplate(false);
|
|
|
|
case tt.doubleColon:
|
|
node = this.startNode();
|
|
this.next();
|
|
node.object = null;
|
|
const callee = node.callee = this.parseNoCallExpr();
|
|
if (callee.type === "MemberExpression") {
|
|
return this.finishNode(node, "BindExpression");
|
|
} else {
|
|
this.raise(callee.start, "Binding should be performed on object property.");
|
|
}
|
|
|
|
default:
|
|
this.unexpected();
|
|
}
|
|
}
|
|
|
|
parseFunctionExpression() {
|
|
const node = this.startNode();
|
|
const meta = this.parseIdentifier(true);
|
|
if (this.state.inGenerator && this.eat(tt.dot) && this.hasPlugin("functionSent")) {
|
|
return this.parseMetaProperty(node, meta, "sent");
|
|
} else {
|
|
return this.parseFunction(node, false);
|
|
}
|
|
}
|
|
|
|
parseMetaProperty(node, meta, propertyName) {
|
|
node.meta = meta;
|
|
node.property = this.parseIdentifier(true);
|
|
|
|
if (node.property.name !== propertyName) {
|
|
this.raise(node.property.start, `The only valid meta property for new is ${meta.name}.${propertyName}`);
|
|
}
|
|
|
|
return this.finishNode(node, "MetaProperty");
|
|
}
|
|
|
|
parseLiteral(value, type, startPos, startLoc) {
|
|
startPos = startPos || this.state.start;
|
|
startLoc = startLoc || this.state.startLoc;
|
|
|
|
const node = this.startNodeAt(startPos, startLoc);
|
|
this.addExtra(node, "rawValue", value);
|
|
this.addExtra(node, "raw", this.input.slice(startPos, this.state.end));
|
|
node.value = value;
|
|
this.next();
|
|
return this.finishNode(node, type);
|
|
}
|
|
|
|
parseParenExpression() {
|
|
this.expect(tt.parenL);
|
|
const val = this.parseExpression();
|
|
this.expect(tt.parenR);
|
|
return val;
|
|
}
|
|
|
|
parseParenAndDistinguishExpression(startPos, startLoc, canBeArrow) {
|
|
startPos = startPos || this.state.start;
|
|
startLoc = startLoc || this.state.startLoc;
|
|
|
|
let val;
|
|
this.expect(tt.parenL);
|
|
|
|
const innerStartPos = this.state.start;
|
|
const innerStartLoc = this.state.startLoc;
|
|
const exprList = [];
|
|
const refShorthandDefaultPos = { start: 0 };
|
|
const refNeedsArrowPos = { start: 0 };
|
|
let first = true;
|
|
let spreadStart;
|
|
let optionalCommaStart;
|
|
|
|
while (!this.match(tt.parenR)) {
|
|
if (first) {
|
|
first = false;
|
|
} else {
|
|
this.expect(tt.comma, refNeedsArrowPos.start || null);
|
|
if (this.match(tt.parenR)) {
|
|
optionalCommaStart = this.state.start;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (this.match(tt.ellipsis)) {
|
|
const spreadNodeStartPos = this.state.start;
|
|
const spreadNodeStartLoc = this.state.startLoc;
|
|
spreadStart = this.state.start;
|
|
exprList.push(this.parseParenItem(this.parseRest(), spreadNodeStartPos, spreadNodeStartLoc));
|
|
break;
|
|
} else {
|
|
exprList.push(this.parseMaybeAssign(false, refShorthandDefaultPos, this.parseParenItem, refNeedsArrowPos));
|
|
}
|
|
}
|
|
|
|
const innerEndPos = this.state.start;
|
|
const innerEndLoc = this.state.startLoc;
|
|
this.expect(tt.parenR);
|
|
|
|
let arrowNode = this.startNodeAt(startPos, startLoc);
|
|
if (canBeArrow && this.shouldParseArrow() && (arrowNode = this.parseArrow(arrowNode))) {
|
|
for (const param of exprList) {
|
|
if (param.extra && param.extra.parenthesized) this.unexpected(param.extra.parenStart);
|
|
}
|
|
|
|
return this.parseArrowExpression(arrowNode, exprList);
|
|
}
|
|
|
|
if (!exprList.length) {
|
|
this.unexpected(this.state.lastTokStart);
|
|
}
|
|
if (optionalCommaStart) this.unexpected(optionalCommaStart);
|
|
if (spreadStart) this.unexpected(spreadStart);
|
|
if (refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start);
|
|
if (refNeedsArrowPos.start) this.unexpected(refNeedsArrowPos.start);
|
|
|
|
if (exprList.length > 1) {
|
|
val = this.startNodeAt(innerStartPos, innerStartLoc);
|
|
val.expressions = exprList;
|
|
this.toReferencedList(val.expressions);
|
|
this.finishNodeAt(val, "SequenceExpression", innerEndPos, innerEndLoc);
|
|
} else {
|
|
val = exprList[0];
|
|
}
|
|
|
|
|
|
this.addExtra(val, "parenthesized", true);
|
|
this.addExtra(val, "parenStart", startPos);
|
|
|
|
return val;
|
|
}
|
|
|
|
shouldParseArrow() {
|
|
return !this.canInsertSemicolon();
|
|
}
|
|
|
|
parseArrow(node) {
|
|
if (this.eat(tt.arrow)) {
|
|
return node;
|
|
}
|
|
}
|
|
|
|
parseParenItem(node) {
|
|
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
|
|
|
|
parseNew() {
|
|
const node = this.startNode();
|
|
const meta = this.parseIdentifier(true);
|
|
|
|
if (this.eat(tt.dot)) {
|
|
const metaProp = this.parseMetaProperty(node, meta, "target");
|
|
|
|
if (!this.state.inFunction) {
|
|
this.raise(metaProp.property.start, "new.target can only be used in functions");
|
|
}
|
|
|
|
return metaProp;
|
|
}
|
|
|
|
node.callee = this.parseNoCallExpr();
|
|
|
|
if (this.eat(tt.parenL)) {
|
|
node.arguments = this.parseExprList(tt.parenR);
|
|
this.toReferencedList(node.arguments);
|
|
} else {
|
|
node.arguments = [];
|
|
}
|
|
|
|
return this.finishNode(node, "NewExpression");
|
|
}
|
|
|
|
// Parse template expression.
|
|
|
|
parseTemplateElement(isTagged) {
|
|
const elem = this.startNode();
|
|
if (this.state.value === null) {
|
|
if (!isTagged) {
|
|
this.raise(this.state.invalidTemplateEscapePosition, "Invalid escape sequence in template");
|
|
} else {
|
|
this.state.invalidTemplateEscapePosition = null;
|
|
}
|
|
}
|
|
elem.value = {
|
|
raw: this.input.slice(this.state.start, this.state.end).replace(/\r\n?/g, "\n"),
|
|
cooked: this.state.value
|
|
};
|
|
this.next();
|
|
elem.tail = this.match(tt.backQuote);
|
|
return this.finishNode(elem, "TemplateElement");
|
|
}
|
|
|
|
parseTemplate(isTagged) {
|
|
const node = this.startNode();
|
|
this.next();
|
|
node.expressions = [];
|
|
let curElt = this.parseTemplateElement(isTagged);
|
|
node.quasis = [curElt];
|
|
while (!curElt.tail) {
|
|
this.expect(tt.dollarBraceL);
|
|
node.expressions.push(this.parseExpression());
|
|
this.expect(tt.braceR);
|
|
node.quasis.push(curElt = this.parseTemplateElement(isTagged));
|
|
}
|
|
this.next();
|
|
return this.finishNode(node, "TemplateLiteral");
|
|
}
|
|
|
|
// Parse an object literal or binding pattern.
|
|
|
|
parseObj(isPattern, refShorthandDefaultPos) {
|
|
let decorators = [];
|
|
const propHash = Object.create(null);
|
|
let first = true;
|
|
const node = this.startNode();
|
|
|
|
node.properties = [];
|
|
this.next();
|
|
|
|
let firstRestLocation = null;
|
|
|
|
while (!this.eat(tt.braceR)) {
|
|
if (first) {
|
|
first = false;
|
|
} else {
|
|
this.expect(tt.comma);
|
|
if (this.eat(tt.braceR)) break;
|
|
}
|
|
|
|
while (this.match(tt.at)) {
|
|
decorators.push(this.parseDecorator());
|
|
}
|
|
|
|
let prop = this.startNode(), isGenerator = false, isAsync = false, startPos, startLoc;
|
|
if (decorators.length) {
|
|
prop.decorators = decorators;
|
|
decorators = [];
|
|
}
|
|
|
|
if (this.hasPlugin("objectRestSpread") && this.match(tt.ellipsis)) {
|
|
prop = this.parseSpread(isPattern ? { start: 0 } : undefined);
|
|
prop.type = isPattern ? "RestElement" : "SpreadElement";
|
|
if (isPattern) this.toAssignable(prop.argument, true, "object pattern");
|
|
node.properties.push(prop);
|
|
if (isPattern) {
|
|
const position = this.state.start;
|
|
if (firstRestLocation !== null) {
|
|
this.unexpected(firstRestLocation, "Cannot have multiple rest elements when destructuring");
|
|
} else if (this.eat(tt.braceR)) {
|
|
break;
|
|
} else if (this.match(tt.comma) && this.lookahead().type === tt.braceR) {
|
|
this.unexpected(position, "A trailing comma is not permitted after the rest element");
|
|
} else {
|
|
firstRestLocation = position;
|
|
continue;
|
|
}
|
|
} else {
|
|
continue;
|
|
}
|
|
}
|
|
|
|
prop.method = false;
|
|
|
|
if (isPattern || refShorthandDefaultPos) {
|
|
startPos = this.state.start;
|
|
startLoc = this.state.startLoc;
|
|
}
|
|
|
|
if (!isPattern) {
|
|
isGenerator = this.eat(tt.star);
|
|
}
|
|
|
|
if (!isPattern && this.isContextual("async")) {
|
|
if (isGenerator) this.unexpected();
|
|
|
|
const asyncId = this.parseIdentifier();
|
|
if (this.match(tt.colon) || this.match(tt.parenL) || this.match(tt.braceR) || this.match(tt.eq) || this.match(tt.comma)) {
|
|
prop.key = asyncId;
|
|
prop.computed = false;
|
|
} else {
|
|
isAsync = true;
|
|
if (this.hasPlugin("asyncGenerators")) isGenerator = this.eat(tt.star);
|
|
this.parsePropertyName(prop);
|
|
}
|
|
} else {
|
|
this.parsePropertyName(prop);
|
|
}
|
|
|
|
this.parseObjPropValue(prop, startPos, startLoc, isGenerator, isAsync, isPattern, refShorthandDefaultPos);
|
|
this.checkPropClash(prop, propHash);
|
|
|
|
if (prop.shorthand) {
|
|
this.addExtra(prop, "shorthand", true);
|
|
}
|
|
|
|
node.properties.push(prop);
|
|
}
|
|
|
|
if (firstRestLocation !== null) {
|
|
this.unexpected(firstRestLocation, "The rest element has to be the last element when destructuring");
|
|
}
|
|
|
|
if (decorators.length) {
|
|
this.raise(this.state.start, "You have trailing decorators with no property");
|
|
}
|
|
|
|
return this.finishNode(node, isPattern ? "ObjectPattern" : "ObjectExpression");
|
|
}
|
|
|
|
isGetterOrSetterMethod(prop, isPattern) {
|
|
return !isPattern &&
|
|
!prop.computed &&
|
|
prop.key.type === "Identifier" &&
|
|
(prop.key.name === "get" || prop.key.name === "set") &&
|
|
(
|
|
this.match(tt.string) || // get "string"() {}
|
|
this.match(tt.num) || // get 1() {}
|
|
this.match(tt.bracketL) || // get ["string"]() {}
|
|
this.match(tt.name) || // get foo() {}
|
|
this.state.type.keyword // get debugger() {}
|
|
);
|
|
}
|
|
|
|
// get methods aren't allowed to have any parameters
|
|
// set methods must have exactly 1 parameter
|
|
checkGetterSetterParamCount(method) {
|
|
const paramCount = method.kind === "get" ? 0 : 1;
|
|
if (method.params.length !== paramCount) {
|
|
const start = method.start;
|
|
if (method.kind === "get") {
|
|
this.raise(start, "getter should have no params");
|
|
} else {
|
|
this.raise(start, "setter should have exactly one param");
|
|
}
|
|
}
|
|
}
|
|
|
|
parseObjectMethod(prop, isGenerator, isAsync, isPattern) {
|
|
if (isAsync || isGenerator || this.match(tt.parenL)) {
|
|
if (isPattern) this.unexpected();
|
|
prop.kind = "method";
|
|
prop.method = true;
|
|
this.parseMethod(prop, isGenerator, isAsync);
|
|
|
|
return this.finishNode(prop, "ObjectMethod");
|
|
}
|
|
|
|
if (this.isGetterOrSetterMethod(prop, isPattern)) {
|
|
if (isGenerator || isAsync) this.unexpected();
|
|
prop.kind = prop.key.name;
|
|
this.parsePropertyName(prop);
|
|
this.parseMethod(prop);
|
|
this.checkGetterSetterParamCount(prop);
|
|
|
|
return this.finishNode(prop, "ObjectMethod");
|
|
}
|
|
}
|
|
|
|
parseObjectProperty(prop, startPos, startLoc, isPattern, refShorthandDefaultPos) {
|
|
prop.shorthand = false;
|
|
|
|
if (this.eat(tt.colon)) {
|
|
prop.value = isPattern ? this.parseMaybeDefault(this.state.start, this.state.startLoc) : this.parseMaybeAssign(false, refShorthandDefaultPos);
|
|
|
|
return this.finishNode(prop, "ObjectProperty");
|
|
}
|
|
|
|
if (!prop.computed && prop.key.type === "Identifier") {
|
|
this.checkReservedWord(prop.key.name, prop.key.start, true, true);
|
|
|
|
if (isPattern) {
|
|
prop.value = this.parseMaybeDefault(startPos, startLoc, prop.key.__clone());
|
|
} else if (this.match(tt.eq) && refShorthandDefaultPos) {
|
|
if (!refShorthandDefaultPos.start) {
|
|
refShorthandDefaultPos.start = this.state.start;
|
|
}
|
|
prop.value = this.parseMaybeDefault(startPos, startLoc, prop.key.__clone());
|
|
} else {
|
|
prop.value = prop.key.__clone();
|
|
}
|
|
prop.shorthand = true;
|
|
|
|
return this.finishNode(prop, "ObjectProperty");
|
|
}
|
|
}
|
|
|
|
parseObjPropValue(prop, startPos, startLoc, isGenerator, isAsync, isPattern, refShorthandDefaultPos) {
|
|
const node =
|
|
this.parseObjectMethod(prop, isGenerator, isAsync, isPattern) ||
|
|
this.parseObjectProperty(prop, startPos, startLoc, isPattern, refShorthandDefaultPos);
|
|
|
|
if (!node) this.unexpected();
|
|
|
|
return node;
|
|
}
|
|
|
|
parsePropertyName(prop) {
|
|
if (this.eat(tt.bracketL)) {
|
|
prop.computed = true;
|
|
prop.key = this.parseMaybeAssign();
|
|
this.expect(tt.bracketR);
|
|
} else {
|
|
prop.computed = false;
|
|
const oldInPropertyName = this.state.inPropertyName;
|
|
this.state.inPropertyName = true;
|
|
prop.key = (this.match(tt.num) || this.match(tt.string)) ? this.parseExprAtom() : this.parseIdentifier(true);
|
|
this.state.inPropertyName = oldInPropertyName;
|
|
}
|
|
return prop.key;
|
|
}
|
|
|
|
// Initialize empty function node.
|
|
|
|
initFunction(node, isAsync) {
|
|
node.id = null;
|
|
node.generator = false;
|
|
node.expression = false;
|
|
node.async = !!isAsync;
|
|
}
|
|
|
|
// Parse object or class method.
|
|
|
|
parseMethod(node, isGenerator, isAsync) {
|
|
const oldInMethod = this.state.inMethod;
|
|
this.state.inMethod = node.kind || true;
|
|
this.initFunction(node, isAsync);
|
|
this.expect(tt.parenL);
|
|
node.params = this.parseBindingList(tt.parenR);
|
|
node.generator = !!isGenerator;
|
|
this.parseFunctionBody(node);
|
|
this.state.inMethod = oldInMethod;
|
|
return node;
|
|
}
|
|
|
|
// Parse arrow function expression with given parameters.
|
|
|
|
parseArrowExpression(node, params, isAsync) {
|
|
this.initFunction(node, isAsync);
|
|
node.params = this.toAssignableList(params, true, "arrow function parameters");
|
|
this.parseFunctionBody(node, true);
|
|
return this.finishNode(node, "ArrowFunctionExpression");
|
|
}
|
|
|
|
isStrictBody(node, isExpression) {
|
|
if (!isExpression && node.body.directives.length) {
|
|
for (const directive of (node.body.directives: Array<Object>)) {
|
|
if (directive.value.value === "use strict") {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// Parse function body and check parameters.
|
|
parseFunctionBody(node, allowExpression) {
|
|
const isExpression = allowExpression && !this.match(tt.braceL);
|
|
|
|
const oldInAsync = this.state.inAsync;
|
|
this.state.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).
|
|
const oldInFunc = this.state.inFunction;
|
|
const oldInGen = this.state.inGenerator;
|
|
const oldLabels = this.state.labels;
|
|
this.state.inFunction = true; this.state.inGenerator = node.generator; this.state.labels = [];
|
|
node.body = this.parseBlock(true);
|
|
node.expression = false;
|
|
this.state.inFunction = oldInFunc; this.state.inGenerator = oldInGen; this.state.labels = oldLabels;
|
|
}
|
|
this.state.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`.
|
|
const isStrict = this.isStrictBody(node, isExpression);
|
|
// Also check when allowExpression === true for arrow functions
|
|
const checkLVal = this.state.strict || allowExpression || isStrict;
|
|
|
|
if (isStrict && node.id && node.id.type === "Identifier" && node.id.name === "yield") {
|
|
this.raise(node.id.start, "Binding yield in strict mode");
|
|
}
|
|
|
|
if (checkLVal) {
|
|
const nameHash = Object.create(null);
|
|
const oldStrict = this.state.strict;
|
|
if (isStrict) this.state.strict = true;
|
|
if (node.id) {
|
|
this.checkLVal(node.id, true, undefined, "function name");
|
|
}
|
|
for (const param of (node.params: Array<Object>)) {
|
|
if (isStrict && param.type !== "Identifier") {
|
|
this.raise(param.start, "Non-simple parameter in strict mode");
|
|
}
|
|
this.checkLVal(param, true, nameHash, "function parameter list");
|
|
}
|
|
this.state.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).
|
|
|
|
parseExprList(close, allowEmpty, refShorthandDefaultPos) {
|
|
const elts = [];
|
|
let first = true;
|
|
|
|
while (!this.eat(close)) {
|
|
if (first) {
|
|
first = false;
|
|
} else {
|
|
this.expect(tt.comma);
|
|
if (this.eat(close)) break;
|
|
}
|
|
|
|
elts.push(this.parseExprListItem(allowEmpty, refShorthandDefaultPos));
|
|
}
|
|
return elts;
|
|
}
|
|
|
|
parseExprListItem(allowEmpty, refShorthandDefaultPos, refNeedsArrowPos) {
|
|
let elt;
|
|
if (allowEmpty && this.match(tt.comma)) {
|
|
elt = null;
|
|
} else if (this.match(tt.ellipsis)) {
|
|
elt = this.parseSpread(refShorthandDefaultPos);
|
|
} else {
|
|
elt = this.parseMaybeAssign(false, refShorthandDefaultPos, this.parseParenItem, refNeedsArrowPos);
|
|
}
|
|
return elt;
|
|
}
|
|
|
|
// Parse the next token as an identifier. If `liberal` is true (used
|
|
// when parsing properties), it will also convert keywords into
|
|
// identifiers.
|
|
|
|
parseIdentifier(liberal) {
|
|
const node = this.startNode();
|
|
if (!liberal) {
|
|
this.checkReservedWord(this.state.value, this.state.start, !!this.state.type.keyword, false);
|
|
}
|
|
|
|
if (this.match(tt.name)) {
|
|
node.name = this.state.value;
|
|
} else if (this.state.type.keyword) {
|
|
node.name = this.state.type.keyword;
|
|
} else {
|
|
this.unexpected();
|
|
}
|
|
|
|
if (!liberal && node.name === "await" && this.state.inAsync) {
|
|
this.raise(node.start, "invalid use of await inside of an async function");
|
|
}
|
|
|
|
node.loc.identifierName = node.name;
|
|
|
|
this.next();
|
|
return this.finishNode(node, "Identifier");
|
|
}
|
|
|
|
checkReservedWord(word, startLoc, checkKeywords, isBinding) {
|
|
if (this.isReservedWord(word) || (checkKeywords && this.isKeyword(word))) {
|
|
this.raise(startLoc, word + " is a reserved word");
|
|
}
|
|
|
|
if (this.state.strict && (reservedWords.strict(word) || (isBinding && reservedWords.strictBind(word)))) {
|
|
this.raise(startLoc, word + " is a reserved word in strict mode");
|
|
}
|
|
}
|
|
|
|
// Parses await expression inside async function.
|
|
|
|
parseAwait(node) {
|
|
// istanbul ignore next: this condition is checked at the call site so won't be hit here
|
|
if (!this.state.inAsync) {
|
|
this.unexpected();
|
|
}
|
|
if (this.match(tt.star)) {
|
|
this.raise(node.start, "await* has been removed from the async functions proposal. Use Promise.all() instead.");
|
|
}
|
|
node.argument = this.parseMaybeUnary();
|
|
return this.finishNode(node, "AwaitExpression");
|
|
}
|
|
|
|
// Parses yield expression inside generator.
|
|
|
|
parseYield() {
|
|
const node = this.startNode();
|
|
this.next();
|
|
if (
|
|
this.match(tt.semi) ||
|
|
this.canInsertSemicolon() ||
|
|
(!this.match(tt.star) && !this.state.type.startsExpr)
|
|
) {
|
|
node.delegate = false;
|
|
node.argument = null;
|
|
} else {
|
|
node.delegate = this.eat(tt.star);
|
|
node.argument = this.parseMaybeAssign();
|
|
}
|
|
return this.finishNode(node, "YieldExpression");
|
|
}
|
|
}
|