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Diffstat (limited to 'node_modules/acorn/src/parseutil.js')
-rw-r--r-- | node_modules/acorn/src/parseutil.js | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/node_modules/acorn/src/parseutil.js b/node_modules/acorn/src/parseutil.js new file mode 100644 index 000000000..ffa005030 --- /dev/null +++ b/node_modules/acorn/src/parseutil.js @@ -0,0 +1,128 @@ +import {types as tt} from "./tokentype" +import {Parser} from "./state" +import {lineBreak, skipWhiteSpace} from "./whitespace" + +const pp = Parser.prototype + +// ## Parser utilities + +const literal = /^(?:'((?:[^']|\.)*)'|"((?:[^"]|\.)*)"|;)/ +pp.strictDirective = function(start) { + for (;;) { + skipWhiteSpace.lastIndex = start + start += skipWhiteSpace.exec(this.input)[0].length + let match = literal.exec(this.input.slice(start)) + if (!match) return false + if ((match[1] || match[2]) == "use strict") return true + start += match[0].length + } +} + +// Predicate that tests whether the next token is of the given +// type, and if yes, consumes it as a side effect. + +pp.eat = function(type) { + if (this.type === type) { + this.next() + return true + } else { + return false + } +} + +// Tests whether parsed token is a contextual keyword. + +pp.isContextual = function(name) { + return this.type === tt.name && this.value === name +} + +// Consumes contextual keyword if possible. + +pp.eatContextual = function(name) { + return this.value === name && this.eat(tt.name) +} + +// Asserts that following token is given contextual keyword. + +pp.expectContextual = function(name) { + if (!this.eatContextual(name)) this.unexpected() +} + +// Test whether a semicolon can be inserted at the current position. + +pp.canInsertSemicolon = function() { + return this.type === tt.eof || + this.type === tt.braceR || + lineBreak.test(this.input.slice(this.lastTokEnd, this.start)) +} + +pp.insertSemicolon = function() { + if (this.canInsertSemicolon()) { + if (this.options.onInsertedSemicolon) + this.options.onInsertedSemicolon(this.lastTokEnd, this.lastTokEndLoc) + return true + } +} + +// Consume a semicolon, or, failing that, see if we are allowed to +// pretend that there is a semicolon at this position. + +pp.semicolon = function() { + if (!this.eat(tt.semi) && !this.insertSemicolon()) this.unexpected() +} + +pp.afterTrailingComma = function(tokType, notNext) { + if (this.type == tokType) { + if (this.options.onTrailingComma) + this.options.onTrailingComma(this.lastTokStart, this.lastTokStartLoc) + if (!notNext) + this.next() + return true + } +} + +// Expect a token of a given type. If found, consume it, otherwise, +// raise an unexpected token error. + +pp.expect = function(type) { + this.eat(type) || this.unexpected() +} + +// Raise an unexpected token error. + +pp.unexpected = function(pos) { + this.raise(pos != null ? pos : this.start, "Unexpected token") +} + +export class DestructuringErrors { + constructor() { + this.shorthandAssign = this.trailingComma = this.parenthesizedAssign = this.parenthesizedBind = -1 + } +} + +pp.checkPatternErrors = function(refDestructuringErrors, isAssign) { + if (!refDestructuringErrors) return + if (refDestructuringErrors.trailingComma > -1) + this.raiseRecoverable(refDestructuringErrors.trailingComma, "Comma is not permitted after the rest element") + let parens = isAssign ? refDestructuringErrors.parenthesizedAssign : refDestructuringErrors.parenthesizedBind + if (parens > -1) this.raiseRecoverable(parens, "Parenthesized pattern") +} + +pp.checkExpressionErrors = function(refDestructuringErrors, andThrow) { + let pos = refDestructuringErrors ? refDestructuringErrors.shorthandAssign : -1 + if (!andThrow) return pos >= 0 + if (pos > -1) this.raise(pos, "Shorthand property assignments are valid only in destructuring patterns") +} + +pp.checkYieldAwaitInDefaultParams = function() { + if (this.yieldPos && (!this.awaitPos || this.yieldPos < this.awaitPos)) + this.raise(this.yieldPos, "Yield expression cannot be a default value") + if (this.awaitPos) + this.raise(this.awaitPos, "Await expression cannot be a default value") +} + +pp.isSimpleAssignTarget = function(expr) { + if (expr.type === "ParenthesizedExpression") + return this.isSimpleAssignTarget(expr.expression) + return expr.type === "Identifier" || expr.type === "MemberExpression" +} |