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- var _getLength = require('./_getLength.js');
- var isFunction = require('./isFunction.js');
- // Internal function for linearly iterating over arrays.
- function linearSearch(array, predicate, dir, start) {
- var target, length = _getLength(array);
- dir || (dir = 1);
- start = (
- start == null ? (dir > 0 ? 0 : length - 1) :
- start < 0 ? (dir > 0 ? Math.max(0, start + length) : start + length) :
- dir > 0 ? start : Math.min(start, length - 1)
- );
- // As a special case, in order to elide the `predicate` invocation on every
- // loop iteration, we allow the caller to pass a value that should be found by
- // strict equality comparison. This is somewhat like a rudimentary iteratee
- // shorthand. It is used in `_.indexof` and `_.lastIndexOf`.
- if (!isFunction(predicate)) {
- target = predicate && predicate.value;
- predicate = false;
- }
- for (; start >= 0 && start < length; start += dir) {
- if (
- predicate ? predicate(array[start], start, array) :
- array[start] === target
- ) return start;
- }
- return -1;
- }
- module.exports = linearSearch;
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