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							299 lines
						
					
					
						
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				"use strict"; | 
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Object.defineProperty(exports, "__esModule", { value: true }); | 
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exports.FunctionParser = exports.dedentFunction = exports.functionToString = exports.USED_METHOD_KEY = void 0; | 
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const quote_1 = require("./quote"); | 
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/** | 
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 * Used in function stringification. | 
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 */ | 
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/* istanbul ignore next */ | 
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const METHOD_NAMES_ARE_QUOTED = { | 
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    " "() { | 
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        /* Empty. */ | 
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    }, | 
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}[" "] | 
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    .toString() | 
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    .charAt(0) === '"'; | 
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const FUNCTION_PREFIXES = { | 
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    Function: "function ", | 
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    GeneratorFunction: "function* ", | 
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    AsyncFunction: "async function ", | 
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    AsyncGeneratorFunction: "async function* ", | 
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}; | 
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const METHOD_PREFIXES = { | 
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    Function: "", | 
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    GeneratorFunction: "*", | 
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    AsyncFunction: "async ", | 
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    AsyncGeneratorFunction: "async *", | 
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}; | 
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const TOKENS_PRECEDING_REGEXPS = new Set(("case delete else in instanceof new return throw typeof void " + | 
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    ", ; : + - ! ~ & | ^ * / % < > ? =").split(" ")); | 
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/** | 
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 * Track function parser usage. | 
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 */ | 
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exports.USED_METHOD_KEY = new WeakSet(); | 
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/** | 
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 * Stringify a function. | 
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 */ | 
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const functionToString = (fn, space, next, key) => { | 
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    const name = typeof key === "string" ? key : undefined; | 
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    // Track in function parser for object stringify to avoid duplicate output. | 
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    if (name !== undefined) | 
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        exports.USED_METHOD_KEY.add(fn); | 
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    return new FunctionParser(fn, space, next, name).stringify(); | 
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}; | 
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exports.functionToString = functionToString; | 
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/** | 
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 * Rewrite a stringified function to remove initial indentation. | 
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 */ | 
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function dedentFunction(fnString) { | 
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    let found; | 
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    for (const line of fnString.split("\n").slice(1)) { | 
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        const m = /^[\s\t]+/.exec(line); | 
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        if (!m) | 
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            return fnString; // Early exit without indent. | 
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        const [str] = m; | 
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        if (found === undefined) | 
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            found = str; | 
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        else if (str.length < found.length) | 
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            found = str; | 
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    } | 
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    return found ? fnString.split(`\n${found}`).join("\n") : fnString; | 
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} | 
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exports.dedentFunction = dedentFunction; | 
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/** | 
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 * Function parser and stringify. | 
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 */ | 
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class FunctionParser { | 
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    constructor(fn, indent, next, key) { | 
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        this.fn = fn; | 
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        this.indent = indent; | 
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        this.next = next; | 
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        this.key = key; | 
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        this.pos = 0; | 
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        this.hadKeyword = false; | 
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        this.fnString = Function.prototype.toString.call(fn); | 
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        this.fnType = fn.constructor.name; | 
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        this.keyQuote = key === undefined ? "" : quote_1.quoteKey(key, next); | 
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        this.keyPrefix = | 
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            key === undefined ? "" : `${this.keyQuote}:${indent ? " " : ""}`; | 
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        this.isMethodCandidate = | 
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            key === undefined ? false : this.fn.name === "" || this.fn.name === key; | 
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    } | 
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    stringify() { | 
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        const value = this.tryParse(); | 
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        // If we can't stringify this function, return a void expression; for | 
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        // bonus help with debugging, include the function as a string literal. | 
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        if (!value) { | 
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            return `${this.keyPrefix}void ${this.next(this.fnString)}`; | 
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        } | 
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        return dedentFunction(value); | 
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    } | 
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    getPrefix() { | 
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        if (this.isMethodCandidate && !this.hadKeyword) { | 
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            return METHOD_PREFIXES[this.fnType] + this.keyQuote; | 
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        } | 
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        return this.keyPrefix + FUNCTION_PREFIXES[this.fnType]; | 
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    } | 
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    tryParse() { | 
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        if (this.fnString[this.fnString.length - 1] !== "}") { | 
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            // Must be an arrow function. | 
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            return this.keyPrefix + this.fnString; | 
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        } | 
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        // Attempt to remove function prefix. | 
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        if (this.fn.name) { | 
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            const result = this.tryStrippingName(); | 
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            if (result) | 
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                return result; | 
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        } | 
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        // Support class expressions. | 
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        const prevPos = this.pos; | 
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        if (this.consumeSyntax() === "class") | 
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            return this.fnString; | 
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        this.pos = prevPos; | 
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        if (this.tryParsePrefixTokens()) { | 
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            const result = this.tryStrippingName(); | 
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            if (result) | 
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                return result; | 
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            let offset = this.pos; | 
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            switch (this.consumeSyntax("WORD_LIKE")) { | 
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                case "WORD_LIKE": | 
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                    if (this.isMethodCandidate && !this.hadKeyword) { | 
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                        offset = this.pos; | 
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                    } | 
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                case "()": | 
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                    if (this.fnString.substr(this.pos, 2) === "=>") { | 
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                        return this.keyPrefix + this.fnString; | 
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                    } | 
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                    this.pos = offset; | 
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                case '"': | 
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                case "'": | 
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                case "[]": | 
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                    return this.getPrefix() + this.fnString.substr(this.pos); | 
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            } | 
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        } | 
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    } | 
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    /** | 
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     * Attempt to parse the function from the current position by first stripping | 
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     * the function's name from the front. This is not a fool-proof method on all | 
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     * JavaScript engines, but yields good results on Node.js 4 (and slightly | 
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     * less good results on Node.js 6 and 8). | 
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     */ | 
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    tryStrippingName() { | 
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        if (METHOD_NAMES_ARE_QUOTED) { | 
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            // ... then this approach is unnecessary and yields false positives. | 
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            return; | 
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        } | 
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        let start = this.pos; | 
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        const prefix = this.fnString.substr(this.pos, this.fn.name.length); | 
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        if (prefix === this.fn.name) { | 
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            this.pos += prefix.length; | 
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            if (this.consumeSyntax() === "()" && | 
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                this.consumeSyntax() === "{}" && | 
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                this.pos === this.fnString.length) { | 
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                // Don't include the function's name if it will be included in the | 
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                // prefix, or if it's invalid as a name in a function expression. | 
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                if (this.isMethodCandidate || !quote_1.isValidVariableName(prefix)) { | 
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                    start += prefix.length; | 
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                } | 
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                return this.getPrefix() + this.fnString.substr(start); | 
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            } | 
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        } | 
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        this.pos = start; | 
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    } | 
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    /** | 
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     * Attempt to advance the parser past the keywords expected to be at the | 
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     * start of this function's definition. This method sets `this.hadKeyword` | 
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     * based on whether or not a `function` keyword is consumed. | 
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     */ | 
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    tryParsePrefixTokens() { | 
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        let posPrev = this.pos; | 
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        this.hadKeyword = false; | 
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        switch (this.fnType) { | 
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            case "AsyncFunction": | 
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                if (this.consumeSyntax() !== "async") | 
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                    return false; | 
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                posPrev = this.pos; | 
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            case "Function": | 
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                if (this.consumeSyntax() === "function") { | 
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                    this.hadKeyword = true; | 
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                } | 
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                else { | 
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                    this.pos = posPrev; | 
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                } | 
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                return true; | 
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            case "AsyncGeneratorFunction": | 
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                if (this.consumeSyntax() !== "async") | 
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                    return false; | 
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            case "GeneratorFunction": | 
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                let token = this.consumeSyntax(); | 
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                if (token === "function") { | 
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                    token = this.consumeSyntax(); | 
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                    this.hadKeyword = true; | 
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                } | 
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                return token === "*"; | 
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        } | 
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    } | 
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    /** | 
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     * Advance the parser past one element of JavaScript syntax. This could be a | 
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     * matched pair of delimiters, like braces or parentheses, or an atomic unit | 
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     * like a keyword, variable, or operator. Return a normalized string | 
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     * representation of the element parsed--for example, returns '{}' for a | 
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     * matched pair of braces. Comments and whitespace are skipped. | 
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     * | 
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     * (This isn't a full parser, so the token scanning logic used here is as | 
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     * simple as it can be. As a consequence, some things that are one token in | 
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     * JavaScript, like decimal number literals or most multi-character operators | 
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     * like '&&', are split into more than one token here. However, awareness of | 
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     * some multi-character sequences like '=>' is necessary, so we match the few | 
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     * of them that we care about.) | 
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     */ | 
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    consumeSyntax(wordLikeToken) { | 
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        const m = this.consumeMatch(/^(?:([A-Za-z_0-9$\xA0-\uFFFF]+)|=>|\+\+|\-\-|.)/); | 
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        if (!m) | 
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            return; | 
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        const [token, match] = m; | 
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        this.consumeWhitespace(); | 
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        if (match) | 
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            return wordLikeToken || match; | 
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        switch (token) { | 
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            case "(": | 
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                return this.consumeSyntaxUntil("(", ")"); | 
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            case "[": | 
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                return this.consumeSyntaxUntil("[", "]"); | 
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            case "{": | 
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                return this.consumeSyntaxUntil("{", "}"); | 
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            case "`": | 
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                return this.consumeTemplate(); | 
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            case '"': | 
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                return this.consumeRegExp(/^(?:[^\\"]|\\.)*"/, '"'); | 
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            case "'": | 
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                return this.consumeRegExp(/^(?:[^\\']|\\.)*'/, "'"); | 
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        } | 
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        return token; | 
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    } | 
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    consumeSyntaxUntil(startToken, endToken) { | 
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        let isRegExpAllowed = true; | 
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        for (;;) { | 
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            const token = this.consumeSyntax(); | 
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            if (token === endToken) | 
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                return startToken + endToken; | 
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            if (!token || token === ")" || token === "]" || token === "}") | 
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                return; | 
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            if (token === "/" && | 
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                isRegExpAllowed && | 
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                this.consumeMatch(/^(?:\\.|[^\\\/\n[]|\[(?:\\.|[^\]])*\])+\/[a-z]*/)) { | 
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                isRegExpAllowed = false; | 
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                this.consumeWhitespace(); | 
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            } | 
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            else { | 
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                isRegExpAllowed = TOKENS_PRECEDING_REGEXPS.has(token); | 
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            } | 
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        } | 
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    } | 
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    consumeMatch(re) { | 
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        const m = re.exec(this.fnString.substr(this.pos)); | 
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        if (m) | 
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            this.pos += m[0].length; | 
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        return m; | 
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    } | 
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    /** | 
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     * Advance the parser past an arbitrary regular expression. Return `token`, | 
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     * or the match object of the regexp. | 
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     */ | 
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    consumeRegExp(re, token) { | 
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        const m = re.exec(this.fnString.substr(this.pos)); | 
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        if (!m) | 
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            return; | 
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        this.pos += m[0].length; | 
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        this.consumeWhitespace(); | 
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        return token; | 
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    } | 
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    /** | 
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     * Advance the parser past a template string. | 
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     */ | 
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    consumeTemplate() { | 
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        for (;;) { | 
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            this.consumeMatch(/^(?:[^`$\\]|\\.|\$(?!{))*/); | 
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            if (this.fnString[this.pos] === "`") { | 
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                this.pos++; | 
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                this.consumeWhitespace(); | 
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                return "`"; | 
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            } | 
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            if (this.fnString.substr(this.pos, 2) === "${") { | 
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                this.pos += 2; | 
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                this.consumeWhitespace(); | 
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                if (this.consumeSyntaxUntil("{", "}")) | 
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                    continue; | 
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            } | 
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            return; | 
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        } | 
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    } | 
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    /** | 
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     * Advance the parser past any whitespace or comments. | 
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     */ | 
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    consumeWhitespace() { | 
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        this.consumeMatch(/^(?:\s|\/\/.*|\/\*[^]*?\*\/)*/); | 
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    } | 
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} | 
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exports.FunctionParser = FunctionParser; | 
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//# sourceMappingURL=function.js.map
 |