baseFlatten.js
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var isArguments = require('../lang/isArguments'),
isArray = require('../lang/isArray'),
isLength = require('./isLength'),
isObjectLike = require('./isObjectLike');
/**
* The base implementation of `_.flatten` with added support for restricting
* flattening and specifying the start index.
*
* @private
* @param {Array} array The array to flatten.
* @param {boolean} isDeep Specify a deep flatten.
* @param {boolean} isStrict Restrict flattening to arrays and `arguments` objects.
* @returns {Array} Returns the new flattened array.
*/
function baseFlatten(array, isDeep, isStrict) {
var index = -1,
length = array.length,
resIndex = -1,
result = [];
while (++index < length) {
var value = array[index];
if (isObjectLike(value) && isLength(value.length) && (isArray(value) || isArguments(value))) {
if (isDeep) {
// Recursively flatten arrays (susceptible to call stack limits).
value = baseFlatten(value, isDeep, isStrict);
}
var valIndex = -1,
valLength = value.length;
result.length += valLength;
while (++valIndex < valLength) {
result[++resIndex] = value[valIndex];
}
} else if (!isStrict) {
result[++resIndex] = value;
}
}
return result;
}
module.exports = baseFlatten;