@aws/pdk
Version:
All documentation is located at: https://aws.github.io/aws-pdk
54 lines (44 loc) • 1.63 kB
JavaScript
var _isArray =
/*#__PURE__*/
require("./_isArray.js");
var _isTransformer =
/*#__PURE__*/
require("./_isTransformer.js");
/**
* Returns a function that dispatches with different strategies based on the
* object in list position (last argument). If it is an array, executes [fn].
* Otherwise, if it has a function with one of the given method names, it will
* execute that function (functor case). Otherwise, if it is a transformer,
* uses transducer created by [transducerCreator] to return a new transformer
* (transducer case).
* Otherwise, it will default to executing [fn].
*
* @private
* @param {Array} methodNames properties to check for a custom implementation
* @param {Function} transducerCreator transducer factory if object is transformer
* @param {Function} fn default ramda implementation
* @return {Function} A function that dispatches on object in list position
*/
function _dispatchable(methodNames, transducerCreator, fn) {
return function () {
if (arguments.length === 0) {
return fn();
}
var obj = arguments[arguments.length - 1];
if (!_isArray(obj)) {
var idx = 0;
while (idx < methodNames.length) {
if (typeof obj[methodNames[idx]] === 'function') {
return obj[methodNames[idx]].apply(obj, Array.prototype.slice.call(arguments, 0, -1));
}
idx += 1;
}
if (_isTransformer(obj)) {
var transducer = transducerCreator.apply(null, Array.prototype.slice.call(arguments, 0, -1));
return transducer(obj);
}
}
return fn.apply(this, arguments);
};
}
module.exports = _dispatchable;