makeIterator_.js
1.07 KB
define(['./identity', './prop', '../object/deepMatches'], function(identity, prop, deepMatches) {
/**
* Converts argument into a valid iterator.
* Used internally on most array/object/collection methods that receives a
* callback/iterator providing a shortcut syntax.
*/
function makeIterator(src, thisObj){
if (src == null) {
return identity;
}
switch(typeof src) {
case 'function':
// function is the first to improve perf (most common case)
// also avoid using `Function#call` if not needed, which boosts
// perf a lot in some cases
return (typeof thisObj !== 'undefined')? function(val, i, arr){
return src.call(thisObj, val, i, arr);
} : src;
case 'object':
return function(val){
return deepMatches(val, src);
};
case 'string':
case 'number':
return prop(src);
}
}
return makeIterator;
});