rescript-lang · jmagaram · Mar 29, 2023 · Mar 29, 2023 · Mar 29, 2023 · Mar 29, 2023
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### API changes

 - Add `Result.forEach` https://github.com/rescript-association/rescript-core/pull/116
+- Add missing Array functions : `indexOfFromOpt`, `findLast`, `findLastIndex`, `findLastIndexOpt`, `findLastIndexWithIndex`, `findLastIndexWithIndexOpt` https://github.com/rescript-association/rescript-core/pull/126/files

 ## 0.2.0


diff --git a/src/Core__Array.mjs b/src/Core__Array.mjs
@@ -138,11 +138,36 @@ function findMap(arr, f) {
  };
 }

+function findLastIndexOpt(xs, pred) {
+  var inx = xs.findLastIndex(pred);
+  if (inx !== -1) {
+    return inx;
+  }
+
+}
+
+function findLastIndexWithIndexOpt(xs, pred) {
+  var inx = xs.findLastIndex(pred);
+  if (inx !== -1) {
+    return inx;
+  }
+
+}
+
+function indexOfFromOpt(xs, val, fromInx) {
+  var inx = xs.indexOf(val, fromInx);
+  if (inx !== -1) {
+    return inx;
+  }
+
+}
+
 export {
  make ,
  fromInitializer ,
  sort ,
  indexOfOpt ,
+  indexOfFromOpt ,
  lastIndexOfOpt ,
  reduce ,
  reduceWithIndex ,
@@ -155,5 +180,7 @@ export {
  shuffle ,
  shuffleInPlace ,
  findMap ,
+  findLastIndexOpt ,
+  findLastIndexWithIndexOpt ,
 }
 /* No side effect */
diff --git a/src/Core__Array.res b/src/Core__Array.res
@@ -214,3 +214,30 @@ let findMap = (arr, f) => {
 }

 @send external at: (array<'a>, int) => option<'a> = "at"
+
+@send
+external findLast: (array<'a>, 'a => bool) => option<'a> = "findLast"
+
+@send
+external findLastIndex: (array<'a>, 'a => bool) => int = "findLastIndex"
+
+let findLastIndexOpt = (xs, pred) =>
+  switch findLastIndex(xs, pred) {
+  | -1 => None
+  | inx => Some(inx)
+  }
+
+@send
+external findLastIndexWithIndex: (array<'a>, ('a, int) => bool) => int = "findLastIndex"
+
+let findLastIndexWithIndexOpt = (xs, pred) =>
+  switch findLastIndexWithIndex(xs, pred) {
+  | -1 => None
+  | inx => Some(inx)
+  }
+
+let indexOfFromOpt = (xs, val, fromInx) =>
+  switch indexOfFrom(xs, val, fromInx) {
+  | -1 => None
+  | inx => Some(inx)
+  }
diff --git a/src/Core__Array.resi b/src/Core__Array.resi
@@ -369,8 +369,11 @@ Console.log([{"language": "ReScript"}]->Array.indexOfOpt({"language": "ReScript"
 ```
 */
 let indexOfOpt: (array<'a>, 'a) => option<int>
+
 @send external indexOfFrom: (array<'a>, 'a, int) => int = "indexOf"

+let indexOfFromOpt: (array<'a>, 'a, int) => option<int>
+
 /**
 `joinWith(array, separator)` produces a string where all items of `array` are printed, separated by `separator`. Under the hood this will run JavaScript's `toString` on all the array items.

@@ -383,9 +386,53 @@ Console.log(array->Array.joinWith(" -- ")) // 1 -- 2 -- 3
 */
 @send
 external joinWith: (array<'a>, string) => string = "join"
-@send external lastIndexOf: (array<'a>, 'a) => int = "lastIndexOf"
+
+/**
+`lastIndexOf(array, item)` returns the last index of `item` in `array`, or `-1` if it is not present. **Note:** [Strict equality](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Strict_equality) is used when searching, which may produce unexpected results; use `Array.findLastIndexOf` to search by value.
+
+See [Array.lastIndexOf on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/lastIndexOf).
+
+## Examples
+```rescript
+[3, 5, 7, 5, 8]->Array.lastIndexOf(5) // 3
+[3, 5, 7, 5, 8]->Array.lastIndexOf(99) // -1
+[{"color": "red"}]->Array.lastIndexOf({"color": "red"}) // -1, because of strict equality
+```
+*/
+@send
+external lastIndexOf: (array<'a>, 'a) => int = "lastIndexOf"
+
+/**
+`lastIndexOfOpt(array, item)` returns the last index of `item` in `array`, or `None` if it is not present. **Note:** [Strict equality](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Strict_equality) is used when searching, which may produce unexpected results; use `Array.findLastIndexOf` to search by value.
+
+See [Array.lastIndexOf on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/lastIndexOf).
+
+## Examples
+```rescript
+[3, 5, 7, 5, 8]->Array.lastIndexOf(5) // Some(3)
+[3, 5, 7, 5, 8]->Array.lastIndexOf(99) // None
+[{"color": "red"}]->Array.lastIndexOf({"color": "red"}) // None, because of strict equality
+```
+*/
 let lastIndexOfOpt: (array<'a>, 'a) => option<int>
-@send external lastIndexOfFrom: (array<'a>, 'a, int) => int = "lastIndexOf"
+
+/**
+`lastIndexOfFrom(array, item, fromIndex)` returns the last index of `item` in `array`, or `-1` if it is not present. The search begins at `fromIndex`. A negative index counts back from the end of the array.
+
+**Note:** [Strict equality](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Strict_equality) is used when searching, which may produce unexpected results; use `Array.findLastIndexOf` to search by value.
+
+See [Array.lastIndexOf on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/lastIndexOf).
+
+## Examples
+```rescript
+[3, 5, 7, 5, 8]->Array.lastIndexOfFrom(5, -3) // 1
+[3, 5, 7, 5, 8]->Array.lastIndexOfFrom(5, 4) // 3
+[3, 5, 7, 5, 8]->Array.lastIndexOfFrom(5, 0) // -1
+[{"color": "red"}]->Array.lastIndexOfFrom({"color": "red"}, 99) // -1, because of strict equality
+```
+*/
+@send
+external lastIndexOfFrom: (array<'a>, 'a, int) => int = "lastIndexOf"

 /**
 `slice(array, ~start, ~end)` creates a new array of items copied from `array` from `start` until (but not including) `end`.
@@ -955,3 +1002,81 @@ let findMap: (array<'a>, 'a => option<'b>) => option<'b>
 */
 @send
 external at: (array<'a>, int) => option<'a> = "at"
+
+/**
+`findLast(array, predicate)` iterates the array in **reverse** order and returns the value of the first element that satisfies the provided testing function. Returns `None` if no elements satisfy the predicate.
+
+See [Array.findLast on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLast)
+
+## Examples
+```rescript
+let nums = [3, 5, 7, 5, 8] 
+nums->Array.findLast(i => i < 7) // Some(5)
+nums->Array.findLast(i=> i > 100) // None
+[]->Array.findLast(_ => true) // None
+```
+*/
+@send
+external findLast: (array<'a>, 'a => bool) => option<'a> = "findLast"
+
+/**
+`findLastIndex(array, predicate)` iterates the array in **reverse** order and returns the index of the first element that satisfies the provided testing function. Returns `-1` if no elements satisfy the predicate.
+
+See [Array.findLastIndex on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
+
+## Examples
+```rescript
+let nums = [3, 5, 7, 5, 8]
+nums->Array.findLastIndex(i => i < 7) // 3
+nums->Array.findLast(i => i > 100) // -1
+[]->Array.findLast(_ => true) // -1
+```
+*/
+@send
+external findLastIndex: (array<'a>, 'a => bool) => int = "findLastIndex"
+
+/**
+`findLastIndexOpt(array, predicate)` iterates the array in **reverse** order and returns the index of the first element that satisfies the provided testing function. Returns `None` if no elements satisfy the predicate.
+
+See [Array.findLastIndex on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
+
+## Examples
+```rescript
+let nums = [3, 5, 7, 5, 8] 
+nums->Array.findLastIndex(i => i < 7) // Some(3)
+nums->Array.findLast(i => i > 100) // None
+[]->Array.findLast(_ => true) // None
+```
+*/
+let findLastIndexOpt: (array<'a>, 'a => bool) => option<int>
+
+/**
+`findLastIndexWithIndex(array, predicate)` iterates the array in **reverse** order and returns the index of the first element that satisfies the callback `predicate`. The callback receives the current element being processed followed by its index. Returns `-1` if no elements satisfy the predicate.
+
+See [Array.findLastIndex on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
+
+## Examples
+```rescript
+let nums = [3, 5, 7, 5, 8] 
+nums->Array.findLastIndexWithIndex((val, inx) => val == 5 && inx <= 2) // 1
+nums->Array.findLastIndexWithIndex((val, inx) => val == 5 && inx >= 1) // 3
+nums->Array.findLastIndexWithIndex((val, inx) => val >= 8 && inx < 2) // -1
+```
+*/
+@send
+external findLastIndexWithIndex: (array<'a>, ('a, int) => bool) => int = "findLastIndex"
+
+/**
+`findLastIndexWithIndexOpt(array, predicate)` iterates the array in **reverse** order and returns the index of the first element that satisfies the callback `predicate`. The callback receives the current element being processed followed by its index. Returns `None` if no elements satisfy the predicate.
+
+See [Array.findLastIndex on MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
+
+## Examples
+```rescript
+let nums = [3, 5, 7, 5, 8] 
+nums->Array.findLastIndexWithIndex((val, inx) => val == 5 && inx <= 2) // 1
+nums->Array.findLastIndexWithIndex((val, inx) => val == 5 && inx >= 1) // 3
+nums->Array.findLastIndexWithIndex((val, inx) => val >= 8 && inx < 2) // None 
+```
+*/
+let findLastIndexWithIndexOpt: (array<'a>, ('a, int) => bool) => option<int>