es.array.splice.js
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'use strict';
var $ = require('../internals/export');
var toObject = require('../internals/to-object');
var toAbsoluteIndex = require('../internals/to-absolute-index');
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
var lengthOfArrayLike = require('../internals/length-of-array-like');
var setArrayLength = require('../internals/array-set-length');
var doesNotExceedSafeInteger = require('../internals/does-not-exceed-safe-integer');
var arraySpeciesCreate = require('../internals/array-species-create');
var createProperty = require('../internals/create-property');
var deletePropertyOrThrow = require('../internals/delete-property-or-throw');
var arrayMethodHasSpeciesSupport = require('../internals/array-method-has-species-support');
var HAS_SPECIES_SUPPORT = arrayMethodHasSpeciesSupport('splice');
var max = Math.max;
var min = Math.min;
// `Array.prototype.splice` method
// https://tc39.es/ecma262/#sec-array.prototype.splice
// with adding support of @@species
$({ target: 'Array', proto: true, forced: !HAS_SPECIES_SUPPORT }, {
splice: function splice(start, deleteCount /* , ...items */) {
var O = toObject(this);
var len = lengthOfArrayLike(O);
var actualStart = toAbsoluteIndex(start, len);
var argumentsLength = arguments.length;
var insertCount, actualDeleteCount, A, k, from, to;
if (argumentsLength === 0) {
insertCount = actualDeleteCount = 0;
} else if (argumentsLength === 1) {
insertCount = 0;
actualDeleteCount = len - actualStart;
} else {
insertCount = argumentsLength - 2;
actualDeleteCount = min(max(toIntegerOrInfinity(deleteCount), 0), len - actualStart);
}
doesNotExceedSafeInteger(len + insertCount - actualDeleteCount);
A = arraySpeciesCreate(O, actualDeleteCount);
for (k = 0; k < actualDeleteCount; k++) {
from = actualStart + k;
if (from in O) createProperty(A, k, O[from]);
}
A.length = actualDeleteCount;
if (insertCount < actualDeleteCount) {
for (k = actualStart; k < len - actualDeleteCount; k++) {
from = k + actualDeleteCount;
to = k + insertCount;
if (from in O) O[to] = O[from];
else deletePropertyOrThrow(O, to);
}
for (k = len; k > len - actualDeleteCount + insertCount; k--) deletePropertyOrThrow(O, k - 1);
} else if (insertCount > actualDeleteCount) {
for (k = len - actualDeleteCount; k > actualStart; k--) {
from = k + actualDeleteCount - 1;
to = k + insertCount - 1;
if (from in O) O[to] = O[from];
else deletePropertyOrThrow(O, to);
}
}
for (k = 0; k < insertCount; k++) {
O[k + actualStart] = arguments[k + 2];
}
setArrayLength(O, len - actualDeleteCount + insertCount);
return A;
}
});