🐛 TRY: positive index only

package.json

@@ -1,10 +1,11 @@
 {
   "name": "extra-array",
-  "version": "4.1.13",
+  "version": "4.1.14",
   "description": "An array is a collection of values, stored contiguously.",
   "main": "index.js",
   "module": "index.mjs",
   "sideEffects": false,
+  "private": true,
   "exports": {
     "require": "./index.js",
     "import": "./index.mjs"

src/index.ts

@@ -309,23 +309,23 @@ export function ientries<T>(x: T[]): IEntries<T> {
 // -------------
 
 /**
- * Get zero-based index for an element in array.
+ * Get unmirrored index for an element in array.
  * @param x an array
- * @param i ±index
- * @returns i' | x[i'] = x[i]; i' ∈ [0, |x|]
+ * @param i mirrored ±index
+ * @returns i' | x.at(i') = x.at(i); i' ∈ [0, |x|]
  */
 export function index<T>(x: T[], i: number): number {
   var X = x.length;
-  return i>=0? Math.min(i, X) : Math.max(X+i, 0);
+  return i>=0? Math.min(i, X) : (i>=-X? X+i : X);
 }
 
 
 /**
- * Get zero-based index range for part of array.
+ * Get unmirrored index range for part of array.
  * @param x an array
- * @param i begin ±index [0]
- * @param I end ±index (exclusive) [|x|]
- * @returns [i', I'] | i' ≤ I'; i', I' ∈ [0, |x|]
+ * @param i begin mirrored ±index [0]
+ * @param I end mirrored ±index (exclusive) [|x|]
+ * @returns [i', I'] | x.slice(i', I') = x.slice(i, I); i' ≤ I'; i', I' ∈ [0, |x|]
  */
 export function indexRange<T>(x: T[], i: number=0, I: number=x.length): [number, number] {
   var X = x.length;
@@ -354,13 +354,10 @@ export function isEmpty<T>(x: T[]): boolean {
 /**
  * Find the length of an array.
  * @param x an array
- * @param i begin ±index [0]
- * @param I end ±index (exclusive) [X]
- * @returns |x[i..I]|
+ * @returns |x|
  */
-export function length<T>(x: T[], i: number=0, I: number=x.length): number {
-  var [i, I] = indexRange(x, i, I);
-  return I-i;
+export function length<T>(x: T[]): number {
+  return x.length;
 }
 export {length as size};
 
@@ -370,7 +367,7 @@ export {length as size};
  * @param x an array
  * @param n new length
  * @param vd default value
- * @returns resized x
+ * @returns x | x[|x|..n] = vd; |x| = n
  */
 export function resize$<T>(x: T[], n: number, vd: T) {
   var X = x.length; x.length = n;
@@ -403,7 +400,7 @@ export function clear$<T>(x: T[]) {
  * @returns x[i]
  */
 export function get<T>(x: T[], i: number): T {
-  return x[index(x, i)];
+  return x[i];
 }
 export {get as at};
 
@@ -419,7 +416,10 @@ export {get as at};
  * @returns [x[i₀], x[i₁], ...] | [i₀, i₁, ...] = is
  */
 export function getAll<T>(x: T[], is: number[]): T[] {
-  return is.map(i => get(x, i));
+  var a = [];
+  for (var i of is)
+    a.push(x[i]);
+  return a;
 }
 
 
@@ -431,7 +431,7 @@ export function getAll<T>(x: T[], is: number[]): T[] {
  */
 export function getPath(x: any[], p: number[]): any {
   for (var i of p)
-    x = is(x)? get(x, i) : undefined;
+    x = Array.isArray(x)? x[i] : undefined;
   return x;
 }
 
@@ -444,8 +444,8 @@ export function getPath(x: any[], p: number[]): any {
  */
 export function hasPath(x: any[], p: number[]): boolean {
   for (var i of p) {
-    if (!is(x)) return false;
-    x = get(x, i);
+    if (!Array.isArray(x)) return false;
+    x = x[i];
   }
   return true;
 }