Use .subarray() instead of manually copying items

geraintluff · MaxGraey · web-flow · commit abfef6d123e5 · 2026-04-06T18:06:31.000+01:00
Co-authored-by: Max Graey &lt;maxgraey@gmail.com&gt;
diff --git a/src/builtins.ts b/src/builtins.ts
@@ -3524,9 +3524,7 @@ function utf16ToUtf8(str: string) : Uint8Array {
       result[utf8Length++] = 0x80 + (codePoint&0x3F);
     }
   }
-  let trimmed = new Uint8Array(utf8Length);
-  for (let i: i32 = 0; i < utf8Length; ++i) trimmed[i] = result[i];
-  return trimmed;
+  return result.subarray(0, utf8Length);
 }
 
 // memory.dataUTF8(value) -> usize

Original file line number	Diff line number	Diff line change
`@@ -3524,9 +3524,7 @@ function utf16ToUtf8(str: string) : Uint8Array {`
`3524`	`3524`	`result[utf8Length++] = 0x80 + (codePoint&0x3F);`
`3525`	`3525`	`}`
`3526`	`3526`	`}`
`3527`		`- let trimmed = new Uint8Array(utf8Length);`
`3528`		`- for (let i: i32 = 0; i < utf8Length; ++i) trimmed[i] = result[i];`
`3529`		`- return trimmed;`
	`3527`	`+ return result.subarray(0, utf8Length);`
`3530`	`3528`	`}`
`3531`	`3529`
`3532`	`3530`	`// memory.dataUTF8(value) -> usize`