es6.js

'use strict';

var toStr = Object.prototype.toString;
var hasSymbols = typeof Symbol === 'function' && typeof Symbol.iterator === 'symbol';
var symbolToStr = hasSymbols ? Symbol.prototype.toString : toStr;

var $isNaN = require('./helpers/isNaN');
var $isFinite = require('./helpers/isFinite');
var MAX_SAFE_INTEGER = Number.MAX_SAFE_INTEGER || Math.pow(2, 53) - 1;

var assign = require('./helpers/assign');
var sign = require('./helpers/sign');
var mod = require('./helpers/mod');
var isPrimitive = require('./helpers/isPrimitive');
var toPrimitive = require('es-to-primitive/es6');
var parseInteger = parseInt;
var bind = require('function-bind');
var strSlice = bind.call(Function.call, String.prototype.slice);
var isBinary = bind.call(Function.call, RegExp.prototype.test, /^0b[01]+$/i);
var isOctal = bind.call(Function.call, RegExp.prototype.test, /^0o[0-7]+$/i);
var nonWS = ['\u0085', '\u200b', '\ufffe'].join('');
var nonWSregex = new RegExp('[' + nonWS + ']', 'g');
var hasNonWS = bind.call(Function.call, RegExp.prototype.test, nonWSregex);
var invalidHexLiteral = /^[-+]0x[0-9a-f]+$/i;
var isInvalidHexLiteral = bind.call(Function.call, RegExp.prototype.test, invalidHexLiteral);

// whitespace from: http://es5.github.io/#x15.5.4.20
// implementation from https://github.com/es-shims/es5-shim/blob/v3.4.0/es5-shim.js#L1304-L1324
var ws = [
	'\x09\x0A\x0B\x0C\x0D\x20\xA0\u1680\u180E\u2000\u2001\u2002\u2003',
	'\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u202F\u205F\u3000\u2028',
	'\u2029\uFEFF'
].join('');
var trimRegex = new RegExp('(^[' + ws + ']+)|([' + ws + ']+$)', 'g');
var replace = bind.call(Function.call, String.prototype.replace);
var trim = function (value) {
	return replace(value, trimRegex, '');
};

var ES5 = require('./es5');

var hasRegExpMatcher = require('is-regex');

// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-abstract-operations
var ES6 = assign(assign({}, ES5), {

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-call-f-v-args
	Call: function Call(F, V) {
		var args = arguments.length > 2 ? arguments[2] : [];
		if (!this.IsCallable(F)) {
			throw new TypeError(F + ' is not a function');
		}
		return F.apply(V, args);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toprimitive
	ToPrimitive: toPrimitive,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toboolean
	// ToBoolean: ES5.ToBoolean,

	// http://www.ecma-international.org/ecma-262/6.0/#sec-tonumber
	ToNumber: function ToNumber(argument) {
		var value = isPrimitive(argument) ? argument : toPrimitive(argument, 'number');
		if (typeof value === 'symbol') {
			throw new TypeError('Cannot convert a Symbol value to a number');
		}
		if (typeof value === 'string') {
			if (isBinary(value)) {
				return this.ToNumber(parseInteger(strSlice(value, 2), 2));
			} else if (isOctal(value)) {
				return this.ToNumber(parseInteger(strSlice(value, 2), 8));
			} else if (hasNonWS(value) || isInvalidHexLiteral(value)) {
				return NaN;
			} else {
				var trimmed = trim(value);
				if (trimmed !== value) {
					return this.ToNumber(trimmed);
				}
			}
		}
		return Number(value);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tointeger
	// ToInteger: ES5.ToNumber,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toint32
	// ToInt32: ES5.ToInt32,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-touint32
	// ToUint32: ES5.ToUint32,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toint16
	ToInt16: function ToInt16(argument) {
		var int16bit = this.ToUint16(argument);
		return int16bit >= 0x8000 ? int16bit - 0x10000 : int16bit;
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-touint16
	// ToUint16: ES5.ToUint16,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toint8
	ToInt8: function ToInt8(argument) {
		var int8bit = this.ToUint8(argument);
		return int8bit >= 0x80 ? int8bit - 0x100 : int8bit;
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-touint8
	ToUint8: function ToUint8(argument) {
		var number = this.ToNumber(argument);
		if ($isNaN(number) || number === 0 || !$isFinite(number)) { return 0; }
		var posInt = sign(number) * Math.floor(Math.abs(number));
		return mod(posInt, 0x100);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-touint8clamp
	ToUint8Clamp: function ToUint8Clamp(argument) {
		var number = this.ToNumber(argument);
		if ($isNaN(number) || number <= 0) { return 0; }
		if (number >= 0xFF) { return 0xFF; }
		var f = Math.floor(argument);
		if (f + 0.5 < number) { return f + 1; }
		if (number < f + 0.5) { return f; }
		if (f % 2 !== 0) { return f + 1; }
		return f;
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tostring
	ToString: function ToString(argument) {
		if (typeof argument === 'symbol') {
			throw new TypeError('Cannot convert a Symbol value to a string');
		}
		return String(argument);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-toobject
	ToObject: function ToObject(value) {
		this.RequireObjectCoercible(value);
		return Object(value);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-topropertykey
	ToPropertyKey: function ToPropertyKey(argument) {
		var key = this.ToPrimitive(argument, String);
		return typeof key === 'symbol' ? symbolToStr.call(key) : this.ToString(key);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
	ToLength: function ToLength(argument) {
		var len = this.ToInteger(argument);
		if (len <= 0) { return 0; } // includes converting -0 to +0
		if (len > MAX_SAFE_INTEGER) { return MAX_SAFE_INTEGER; }
		return len;
	},

	// http://www.ecma-international.org/ecma-262/6.0/#sec-canonicalnumericindexstring
	CanonicalNumericIndexString: function CanonicalNumericIndexString(argument) {
		if (toStr.call(argument) !== '[object String]') {
			throw new TypeError('must be a string');
		}
		if (argument === '-0') { return -0; }
		var n = this.ToNumber(argument);
		if (this.SameValue(this.ToString(n), argument)) { return n; }
		return void 0;
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-requireobjectcoercible
	RequireObjectCoercible: ES5.CheckObjectCoercible,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-isarray
	IsArray: Array.isArray || function IsArray(argument) {
		return toStr.call(argument) === '[object Array]';
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-iscallable
	// IsCallable: ES5.IsCallable,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-isconstructor
	IsConstructor: function IsConstructor(argument) {
		return typeof argument === 'function' && !!argument.prototype; // unfortunately there's no way to truly check this without try/catch `new argument`
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-isextensible-o
	IsExtensible: function IsExtensible(obj) {
		if (!Object.preventExtensions) { return true; }
		if (isPrimitive(obj)) {
			return false;
		}
		return Object.isExtensible(obj);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-isinteger
	IsInteger: function IsInteger(argument) {
		if (typeof argument !== 'number' || $isNaN(argument) || !$isFinite(argument)) {
			return false;
		}
		var abs = Math.abs(argument);
		return Math.floor(abs) === abs;
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-ispropertykey
	IsPropertyKey: function IsPropertyKey(argument) {
		return typeof argument === 'string' || typeof argument === 'symbol';
	},

	// http://www.ecma-international.org/ecma-262/6.0/#sec-isregexp
	IsRegExp: function IsRegExp(argument) {
		if (!argument || typeof argument !== 'object') {
			return false;
		}
		if (hasSymbols) {
			var isRegExp = argument[Symbol.match];
			if (typeof isRegExp !== 'undefined') {
				return ES5.ToBoolean(isRegExp);
			}
		}
		return hasRegExpMatcher(argument);
	},

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevalue
	// SameValue: ES5.SameValue,

	// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero
	SameValueZero: function SameValueZero(x, y) {
		return (x === y) || ($isNaN(x) && $isNaN(y));
	},

	/**
	 * 7.3.2 GetV (V, P)
	 * 1. Assert: IsPropertyKey(P) is true.
	 * 2. Let O be ToObject(V).
	 * 3. ReturnIfAbrupt(O).
	 * 4. Return O.[[Get]](P, V).
	 */
	GetV: function GetV(V, P) {
		// 7.3.2.1
		if (!this.IsPropertyKey(P)) {
			throw new TypeError('Assertion failed: IsPropertyKey(P) is not true');
		}

		// 7.3.2.2-3
		var O = this.ToObject(V);

		// 7.3.2.4
		return O[P];
	},

	/**
	 * 7.3.9 - http://www.ecma-international.org/ecma-262/6.0/#sec-getmethod
	 * 1. Assert: IsPropertyKey(P) is true.
	 * 2. Let func be GetV(O, P).
	 * 3. ReturnIfAbrupt(func).
	 * 4. If func is either undefined or null, return undefined.
	 * 5. If IsCallable(func) is false, throw a TypeError exception.
	 * 6. Return func.
	 */
	GetMethod: function GetMethod(O, P) {
		// 7.3.9.1
		if (!this.IsPropertyKey(P)) {
			throw new TypeError('Assertion failed: IsPropertyKey(P) is not true');
		}

		// 7.3.9.2
		var func = this.GetV(O, P);

		// 7.3.9.4
		if (func == null) {
			return undefined;
		}

		// 7.3.9.5
		if (!this.IsCallable(func)) {
			throw new TypeError(P + 'is not a function');
		}

		// 7.3.9.6
		return func;
	},

	/**
	 * 7.3.1 Get (O, P) - http://www.ecma-international.org/ecma-262/6.0/#sec-get-o-p
	 * 1. Assert: Type(O) is Object.
	 * 2. Assert: IsPropertyKey(P) is true.
	 * 3. Return O.[[Get]](P, O).
	 */
	Get: function Get(O, P) {
		// 7.3.1.1
		if (this.Type(O) !== 'Object') {
			throw new TypeError('Assertion failed: Type(O) is not Object');
		}
		// 7.3.1.2
		if (!this.IsPropertyKey(P)) {
			throw new TypeError('Assertion failed: IsPropertyKey(P) is not true');
		}
		// 7.3.1.3
		return O[P];
	},

	Type: function Type(x) {
		if (typeof x === 'symbol') {
			return 'Symbol';
		}
		return ES5.Type(x);
	},

	// http://www.ecma-international.org/ecma-262/6.0/#sec-speciesconstructor
	SpeciesConstructor: function SpeciesConstructor(O, defaultConstructor) {
		if (this.Type(O) !== 'Object') {
			throw new TypeError('Assertion failed: Type(O) is not Object');
		}
		var C = O.constructor;
		if (typeof C === 'undefined') {
			return defaultConstructor;
		}
		if (this.Type(C) !== 'Object') {
			throw new TypeError('O.constructor is not an Object');
		}
		var S = hasSymbols && Symbol.species ? C[Symbol.species] : undefined;
		if (S == null) {
			return defaultConstructor;
		}
		if (this.IsConstructor(S)) {
			return S;
		}
		throw new TypeError('no constructor found');
	}
});

delete ES6.CheckObjectCoercible; // renamed in ES6 to RequireObjectCoercible

module.exports = ES6;