46 lines
1.4 KiB
JavaScript
46 lines
1.4 KiB
JavaScript
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import _isArray from "./_isArray.js";
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import _isTransformer from "./_isTransformer.js";
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/**
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* Returns a function that dispatches with different strategies based on the
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* object in list position (last argument). If it is an array, executes [fn].
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* Otherwise, if it has a function with one of the given method names, it will
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* execute that function (functor case). Otherwise, if it is a transformer,
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* uses transducer [xf] to return a new transformer (transducer case).
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* Otherwise, it will default to executing [fn].
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*
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* @private
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* @param {Array} methodNames properties to check for a custom implementation
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* @param {Function} xf transducer to initialize if object is transformer
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* @param {Function} fn default ramda implementation
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* @return {Function} A function that dispatches on object in list position
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*/
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export default function _dispatchable(methodNames, xf, fn) {
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return function () {
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if (arguments.length === 0) {
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return fn();
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}
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var args = Array.prototype.slice.call(arguments, 0);
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var obj = args.pop();
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if (!_isArray(obj)) {
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var idx = 0;
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while (idx < methodNames.length) {
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if (typeof obj[methodNames[idx]] === 'function') {
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return obj[methodNames[idx]].apply(obj, args);
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}
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idx += 1;
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}
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if (_isTransformer(obj)) {
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var transducer = xf.apply(null, args);
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return transducer(obj);
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}
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}
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return fn.apply(this, arguments);
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};
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}
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