♻️ refactor: Use startsWith from @string-searching/brute-force.

Maybe this function should go to a separate package at some point. Note
that String.prototype.startsWith could be used if we could restrict
ourselves to pi = 0 and pj = p.length.

Author: make-github-pseudonymous-again

package.json

@@ -58,7 +58,9 @@
     "release": "np --message ':hatching_chick: release: Bumping to v%s.'",
     "test": "ava"
   },
-  "dependencies": {},
+  "dependencies": {
+    "@string-searching/brute-force": "^0.0.1"
+  },
   "devDependencies": {
     "@babel/core": "7.14.0",
     "@babel/preset-env": "7.14.0",

src/index.js

@@ -1,2 +1 @@
-export {default as match} from './match.js';
 export {default as rabinKarp} from './rabinKarp.js';

src/match.js

@@ -1,8 +1,9 @@
 import assert from 'assert';
-import match from './match.js';
+import {startsWith} from '@string-searching/brute-force';
 
 /**
- * Note that q should be random and about m (log m bits) for best performance.
+ * Note that q should be random and about m (that is, log m bits) for best
+ * performance.
  * Make sure d * (q-1) <= Number.MAX_SAFE_INTEGER
  * and q + (q-1) <= Number.MAX_SAFE_INTEGER. Otherwise use bigints.
  *
@@ -53,7 +54,7 @@ const rabinKarp = (code, d, q, one = 1) => {
 		const j = sj - m;
 		let i = si;
 		for (; i < j; ++i) {
-			if (sh === ph && match(m, s, i, p, pi)) yield i;
+			if (sh === ph && startsWith(p, pi, pj, s, i)) yield i;
 
 			sh -= ((code(s[i]) % q) * of) % q;
 			sh += q;
@@ -65,7 +66,7 @@ const rabinKarp = (code, d, q, one = 1) => {
 			console.debug({s: s[i + m], sh, ph, of});
 		}
 
-		if (sh === ph && match(m, s, i, p, pi)) yield i;
+		if (sh === ph && startsWith(p, pi, pj, s, i)) yield i;
 	};
 
 	return findAll;

src/rabinKarp.js

@@ -1344,6 +1344,11 @@
   resolved "https://registry.yarnpkg.com/@sindresorhus/is/-/is-4.0.1.tgz#d26729db850fa327b7cacc5522252194404226f5"
   integrity sha512-Qm9hBEBu18wt1PO2flE7LPb30BHMQt1eQgbV76YntdNk73XZGpn3izvGTYxbGgzXKgbCjiia0uxTd3aTNQrY/g==
 
+"@string-searching/brute-force@^0.0.1":
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/@string-searching/brute-force/-/brute-force-0.0.1.tgz#d0c0f3b07abf88b73af48b05e0d7e8c3a990b8cf"
+  integrity sha512-EcQA4atJJ9YwMSG3DWSvnGSAUMVuby9WjJ+FoF7U4XYpsCu2qyS55IQso6F22wZk6ZwobmwXw3SuQwYUbdwgeQ==
+
 "@string-searching/specification@^0.0.1":
   version "0.0.1"
   resolved "https://registry.yarnpkg.com/@string-searching/specification/-/specification-0.0.1.tgz#25d992d1c11b441bbf0b72dc0045a85bc39991f4"