remove dead code

Author: soliury

src/utils/index.js

@@ -40,35 +40,3 @@ export function link(url) {
 			console.error('An error occurred', err);
 		})
 }
-
-export function substring(str, start, end) {
-	let result = '';
-	let i = 0;
-	while (i < end) {
-		let c = str.charCodeAt(i);
-		if ((c >= 0x0001 && c <= 0x007e) || (0xff60 <= c && c <= 0xff9f)) {
-			result += str[i];
-		}
-		else {
-			end -= 1;
-			result += str[i];
-		}
-		i++;
-	}
-	return result;
-}
-
-
-export function strlen(str) {
-	let len = 0;
-	for (let i = 0; i < str.length; i++) {
-		const c = str.charCodeAt(i);
-		if ((c >= 0x0001 && c <= 0x007e) || (0xff60 <= c && c <= 0xff9f)) {
-			len++;
-		}
-		else {
-			len += 2;
-		}
-	}
-	return len;
-}