45 lines
1.5 KiB
JavaScript
45 lines
1.5 KiB
JavaScript
'use strict';
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var $TypeError = require('es-errors/type');
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var isInteger = require('math-intrinsics/isInteger');
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var Call = require('./Call');
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var Get = require('./Get');
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var ToBoolean = require('./ToBoolean');
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var IsCallable = require('./IsCallable');
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var ToString = require('./ToString');
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var isObject = require('../helpers/isObject');
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// https://262.ecma-international.org/15.0/#sec-findviapredicate
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module.exports = function FindViaPredicate(O, len, direction, predicate, thisArg) {
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if (!isObject(O)) {
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throw new $TypeError('Assertion failed: Type(O) is not Object');
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}
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if (!isInteger(len) || len < 0) {
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throw new $TypeError('Assertion failed: len must be a non-negative integer');
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}
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if (direction !== 'ascending' && direction !== 'descending' && direction !== 'DESCENDING' && direction !== 'ASCENDING') {
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throw new $TypeError('Assertion failed: direction must be ~ASCENDING~ or ~DESCENDING~');
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}
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if (!IsCallable(predicate)) {
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throw new $TypeError('predicate must be callable'); // step 1
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}
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for ( // steps 2-4
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var k = direction === 'ascending' || direction === 'ASCENDING' ? 0 : len - 1;
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direction === 'ascending' || direction === 'ASCENDING' ? k < len : k >= 0;
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k += 1
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) {
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var Pk = ToString(k); // step 4.a
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var kValue = Get(O, Pk); // step 4.c
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var testResult = Call(predicate, thisArg, [kValue, k, O]); // step 4.d
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if (ToBoolean(testResult)) {
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return { '[[Index]]': k, '[[Value]]': kValue }; // step 4.e
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}
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}
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return { '[[Index]]': -1, '[[Value]]': void undefined }; // step 5
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};
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