Commit 6974354

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Merge pull request amejiarosario#56 from nuintun/patch-1

feat(hashmap): Better hash function using TextEncoder Improves hash function using TextEncoder instead of codePointAt Closes amejiarosario#55

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+10

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Lines changed: 10 additions & 3 deletions

Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,9 @@`
`2`	`2`	`const LinkedList = require('../../linked-lists/linked-list');`
`3`	`3`	`const { nextPrime } = require('./primes');`
`4`	`4`
	`5`	`+// Text encoding`
	`6`	`+const encoding = new TextEncoder();`
	`7`	`+`
`5`	`8`	`/**`
`6`	`9`	`* The map holds key-value pairs.`
`7`	`10`	`* Any value (both objects and primitive values) may be used as either a key or a value.`
`@@ -50,12 +53,16 @@ class HashMap {`
`50`	`53`	`* @return {integer} bucket index`
`51`	`54`	`*/`
`52`	`55`	`hashFunction(key) {`
`53`		`- const str = String(key);`
	`56`	`+ const bytes = encoding.encode(key);`
	`57`	`+ const { length } = bytes;`
	`58`	`+`
`54`	`59`	`let hash = 2166136261; // FNV_offset_basis (32 bit)`
`55`		`- for (let i = 0; i < str.length; i += 1) {`
`56`		`- hash ^= str.codePointAt(i); // XOR`
	`60`	`+`
	`61`	`+ for (let i = 0; i < length; ) {`
	`62`	`+ hash ^= bytes[i++]; // XOR`
`57`	`63`	`hash *= 16777619; // 32 bit FNV_prime`
`58`	`64`	`}`
	`65`	`+`
`59`	`66`	`return (hash >>> 0) % this.buckets.length;`
`60`	`67`	`}`
`61`	`68`	`// end::hashFunction[]`

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