22 lines
804 B
JavaScript
22 lines
804 B
JavaScript
function partial(func, ...partialArgs) {
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return partialImpl(func, placeholderSymbol, ...partialArgs);
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}
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function partialImpl(func, placeholder, ...partialArgs) {
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const partialed = function (...providedArgs) {
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let providedArgsIndex = 0;
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const substitutedArgs = partialArgs
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.slice()
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.map(arg => (arg === placeholder ? providedArgs[providedArgsIndex++] : arg));
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const remainingArgs = providedArgs.slice(providedArgsIndex);
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return func.apply(this, substitutedArgs.concat(remainingArgs));
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};
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if (func.prototype) {
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partialed.prototype = Object.create(func.prototype);
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}
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return partialed;
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}
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const placeholderSymbol = Symbol('partial.placeholder');
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partial.placeholder = placeholderSymbol;
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export { partial, partialImpl };
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