32 lines
828 B
JavaScript
32 lines
828 B
JavaScript
/* Totally minimal "typed functions" */
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const addImps = (dest, imps) => {
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if (imps) {
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if (!Array.isArray(imps[0])) imps = [imps]
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for (const imp of imps) dest.push(imp)
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}
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}
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export default function poortf (name, imps) {
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/* This is the (function) object we will return */
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function fn () {
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for (const imp of fn.imps) {
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if (imp[0](arguments)) return imp[1].apply(null, arguments)
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}
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throw new TypeError(
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`TF ${fn.name}: No match for ${arguments[0]}, ${arguments[1]}, ...`)
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}
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/* Now dress it up for use */
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Object.defineProperty(fn, 'name', {value: name})
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fn.imps = []
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addImps(fn.imps, imps)
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fn.addImps = newI => addImps(fn.imps, newI)
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return fn
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}
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export function isTF(x) {
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return typeof x === 'function' && 'imps' in x && Array.isArray(x.imps)
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}
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