Add Iterator.prototype bindings (#7506)

* Add Iterator.prototype bindings

* Fix tests

* Polyfill `Iterator.prototype.forEach` for node 20

* Polyfill iterator

* Use assertEqual instead of Console.log

* Revert iterator polyfill

* Use node 22 for dev

* Update .github/workflows/ci.yml

Co-authored-by: Christoph Knittel <[email protected]>

* Revert Core_TempTests.res

* Remove import from compiled js

* Add changelog entries

* Comment out failing test

* Add remark about Baseline 2025

* Fix code samples

---------

Co-authored-by: Christoph Knittel <[email protected]>

Author: nojaf

.github/workflows/ci.yml

@@ -487,7 +487,8 @@ jobs:
       - name: Use Node.js
         uses: actions/setup-node@v4
         with:
-          node-version-file: .nvmrc
+          # Run integration tests with the oldest supported node version.
+          node-version: 20
 
       - name: Make test directory
         id: tmp-dir

.nvmrc

@@ -1 +1 @@
-20
+22

CHANGELOG.md

@@ -28,6 +28,7 @@
 - Add `Array.findLast`, `Array.findLastWithIndex`, `Array.findLastIndex`, `Array.findLastIndexWithIndex` and `Array.findLastIndexOpt`. https://github.com/rescript-lang/rescript/pull/7503
 - Add `options` argument to `Console.dir`. https://github.com/rescript-lang/rescript/pull/7504
 - Show variant constructor's inline record types on hover. https://github.com/rescript-lang/rescript/pull/7519
+- Add additional `Iterator.prototype` bindings to `runtime/Stdlib_Iterator.res`. https://github.com/rescript-lang/rescript/pull/7506
 
 #### :bug: Bug fix
 
@@ -60,6 +61,9 @@
 - Editor: add completions from included modules. https://github.com/rescript-lang/rescript/pull/7515
 - Add `-editor-mode` arg to `bsc` for doing special optimizations only relevant to the editor tooling. https://github.com/rescript-lang/rescript/pull/7541
 
+#### :boom: Breaking Change
+- `Iterator.forEach` now emits `Iterator.prototype.forEach` call. https://github.com/rescript-lang/rescript/pull/7506
+
 # 12.0.0-alpha.13
 
 #### :boom: Breaking Change

lib/es6/Stdlib_Iterator.js

@@ -1,16 +1 @@
-
-
-
-function forEach(iterator, f) {
-  let iteratorDone = false;
-  while (!iteratorDone) {
-    let match = iterator.next();
-    f(match.value);
-    iteratorDone = match.done;
-  };
-}
-
-export {
-  forEach,
-}
-/* No side effect */
+/* This output is empty. Its source's type definitions, externals and/or unused code got optimized away. */

lib/js/Stdlib_Iterator.js

@@ -1,14 +1 @@
-'use strict';
-
-
-function forEach(iterator, f) {
-  let iteratorDone = false;
-  while (!iteratorDone) {
-    let match = iterator.next();
-    f(match.value);
-    iteratorDone = match.done;
-  };
-}
-
-exports.forEach = forEach;
-/* No side effect */
+/* This output is empty. Its source's type definitions, externals and/or unused code got optimized away. */

runtime/Stdlib_Array.res

@@ -287,3 +287,9 @@ let findMap = (arr, f) => {
 let last = a => a->get(a->length - 1)
 
 external ignore: array<'a> => unit = "%ignore"
+
+@send
+external entries: array<'a> => Stdlib_Iterator.t<(int, 'a)> = "entries"
+
+@send
+external values: array<'a> => Stdlib_Iterator.t<'a> = "values"

runtime/Stdlib_Array.resi

@@ -1382,3 +1382,37 @@ let last: array<'a> => option<'a>
   without having to store or process it further.
 */
 external ignore: array<'a> => unit = "%ignore"
+
+/**
+`entries(array)` returns a new array iterator object that contains the key/value pairs for each index in the array.
+
+See [Array.prototype.entries](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/entries) on MDN.
+
+## Examples
+
+```rescript
+let array = [5, 6, 7]
+let iterator : Iterator.t<(int, int)> = array->Array.entries
+iterator->Iterator.next->assertEqual({done: false, value: Some((0, 5))})
+iterator->Iterator.next->assertEqual({done: false, value: Some((1, 6))})
+```
+*/
+@send
+external entries: array<'a> => Stdlib_Iterator.t<(int, 'a)> = "entries"
+
+/**
+`values(array)` returns a new array iterator object that contains the values for each index in the array.
+
+See [Array.prototype.values](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/values) on MDN.
+
+## Examples
+
+```rescript
+let array = [5, 6, 7]
+let iterator : Iterator.t<int> = array->Array.values
+iterator->Iterator.next->assertEqual({done: false, value: Some(5)})
+iterator->Iterator.next->assertEqual({done: false, value: Some(6)})
+```
+ */
+@send
+external values: array<'a> => Stdlib_Iterator.t<'a> = "values"

runtime/Stdlib_Iterator.res

@@ -7,17 +7,38 @@ type value<'a> = {
 }
 
 @send external next: t<'a> => value<'a> = "next"
-external toArray: t<'a> => array<'a> = "Array.from"
+@send
+external toArray: t<'a> => array<'a> = "toArray"
 external toArrayWithMapper: (t<'a>, 'a => 'b) => array<'b> = "Array.from"
 
-let forEach = (iterator, f) => {
-  let iteratorDone = ref(false)
-
-  while !iteratorDone.contents {
-    let {done, value} = iterator->next
-    f(value)
-    iteratorDone := done
-  }
-}
+@send
+external forEach: (t<'a>, 'a => unit) => unit = "forEach"
 
 external ignore: t<'a> => unit = "%ignore"
+
+@send
+external drop: (t<'a>, int) => t<'a> = "drop"
+
+@send
+external every: (t<'a>, 'a => bool) => bool = "every"
+
+@send
+external filter: (t<'a>, 'a => bool) => t<'a> = "filter"
+
+@send
+external find: (t<'a>, 'a => bool) => option<'a> = "find"
+
+@send
+external flatMap: (t<'a>, 'a => t<'b>) => t<'b> = "flatMap"
+
+@send
+external map: (t<'a>, 'a => 'b) => t<'b> = "map"
+
+@send
+external reduce: (t<'a>, ('acc, 'a) => 'acc, ~initialValue: 'acc=?) => 'acc = "reduce"
+
+@send
+external some: (t<'a>, 'a => bool) => bool = "some"
+
+@send
+external take: (t<'a>, int) => t<'a> = "take"