Implement dropLast/takeLast

src/collection/reduceOrNull.ts

@@ -1,8 +1,8 @@
 export function reduceOrNull<T>(value: T[], accumulate: (acc: T, it: T) => T): T | null {
     if (value.length === 0) return null;
     let acc = value[0];
-    for (let index = 1; index < value.length; index++) {
-        acc = accumulate(acc, value[index]);
+    for (let i = 1; i < value.length; i++) {
+        acc = accumulate(acc, value[i]);
     }
     return acc;
 }