45 lines
1.3 KiB
JavaScript
45 lines
1.3 KiB
JavaScript
'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var $TypeError = GetIntrinsic('%TypeError%');
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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 Type = require('./Type');
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var isInteger = require('../helpers/isInteger');
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module.exports = function FindViaPredicate(O, len, direction, predicate, thisArg) {
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if (Type(O) !== 'Object') {
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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') {
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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' ? 0 : len - 1;
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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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