mary.my.id
small array utilities
feat: cluster function
author
Mary
date
(Feb 2, 2025, 11:49 AM +0700)
commit
54d0e43c
54d0e43c12d302b0476dd1a068ac5035691b0ce7
parent
d6f006da
d6f006da243134efec828df2e7dedc5347025b4b
+34
+34
lib/mod.ts
+34
lib/mod.ts
···
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};
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/**
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* groups subsequent elements from an array based on a predicate
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* @param array array to cluster
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* @param predicate function to test consecutive elements with
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* @returns an array of clusters, where each cluster is an array of consecutive elements that satisfy the predicate
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*/
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/*#__NO_SIDE_EFFECTS__*/
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export const cluster = <T>(array: T[], predicate: (a: T, b: T) => unknown): T[][] => {
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const len = array.length;
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if (len === 0) {
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return [];
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}
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let prev = array[0];
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let current = [prev];
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const clusters: T[][] = [current];
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for (let idx = 1; idx < len; idx++) {
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const item = array[idx];
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if (predicate(prev, item)) {
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current.push(item);
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} else {
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clusters.push(current = [item]);
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}
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prev = item;
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}
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return clusters;
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};
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/**
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* returns elements present in the first array but not in the second
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* @param a the source array
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* @param b the array to compare against