Add Array.removeInPlace

CHANGELOG.md

@@ -16,6 +16,7 @@
 
 - Add `Dict.has` and double `Dict.forEachWithKey`/`Dict.mapValues` performance. https://github.com/rescript-lang/rescript/pull/7316
 - Add popover attributes to JsxDOM.domProps. https://github.com/rescript-lang/rescript/pull/7317
+- Add `Array.removeInPlace` helper based on `splice`. https://github.com/rescript-lang/rescript/pull/7321
 - Add `inert` attribute to `JsxDOM.domProps`. https://github.com/rescript-lang/rescript/pull/7326
 
 #### :boom: Breaking Change

runtime/Stdlib_Array.res

@@ -108,6 +108,9 @@ external splice: (array<'a>, ~start: int, ~remove: int, ~insert: array<'a>) => u
 external toSpliced: (array<'a>, ~start: int, ~remove: int, ~insert: array<'a>) => array<'a> =
   "toSpliced"
 
+@send
+external removeInPlace: (array<'a>, int, @as(1) _) => unit = "splice"
+
 @send external with: (array<'a>, int, 'a) => array<'a> = "with"
 
 @send external unshift: (array<'a>, 'a) => unit = "unshift"

runtime/Stdlib_Array.resi

@@ -302,6 +302,9 @@ external splice: (array<'a>, ~start: int, ~remove: int, ~insert: array<'a>) => u
 external toSpliced: (array<'a>, ~start: int, ~remove: int, ~insert: array<'a>) => array<'a> =
   "toSpliced"
 
+@send
+external removeInPlace: (array<'a>, int, @as(1) _) => unit = "splice"
+
 @send external with: (array<'a>, int, 'a) => array<'a> = "with"
 
 /**

tests/tests/src/core/Core_ArrayTests.mjs

@@ -457,6 +457,79 @@ Test.run([
   "last - empty"
 ], Stdlib_Array.last([]), eq, undefined);
 
+let array = [];
+
+array.splice(1, 0, "foo");
+
+Test.run([
+  [
+    "Core_ArrayTests.res",
+    116,
+    22,
+    49
+  ],
+  "splice - Insert no delete"
+], array, eq, ["foo"]);
+
+let array$1 = [
+  "bar",
+  "baz"
+];
+
+Test.run([
+  [
+    "Core_ArrayTests.res",
+    122,
+    15,
+    43
+  ],
+  "splice - Insert and delete"
+], [
+  (array$1.splice(1, 1, "foo"), undefined),
+  array$1
+], eq, [
+  undefined,
+  [
+    "bar",
+    "foo"
+  ]
+]);
+
+let array$2 = [];
+
+array$2.splice(0, 1);
+
+Test.run([
+  [
+    "Core_ArrayTests.res",
+    132,
+    22,
+    45
+  ],
+  "removeInPlace - empty"
+], array$2, eq, []);
+
+let array$3 = [
+  "Hello",
+  "Hi",
+  "Good bye"
+];
+
+array$3.splice(1, 1);
+
+Test.run([
+  [
+    "Core_ArrayTests.res",
+    138,
+    22,
+    51
+  ],
+  "removeInPlace - from middle"
+], array$3, eq, [
+  "Hello",
+  "Good bye"
+]);
+
 export {
   eq,
 }

tests/tests/src/core/Core_ArrayTests.res

@@ -109,3 +109,36 @@ Test.run(
 
 Test.run(__POS_OF__("last - with items"), [1, 2, 3]->Array.last, eq, Some(3))
 Test.run(__POS_OF__("last - empty"), []->Array.last, eq, None)
+
+{
+  let array = []
+  array->Array.splice(~start=1, ~remove=0, ~insert=["foo"])
+  Test.run(__POS_OF__("splice - Insert no delete"), array, eq, ["foo"])
+}
+
+{
+  let array = ["bar", "baz"]
+  Test.run(
+    __POS_OF__("splice - Insert and delete"),
+    (array->Array.splice(~start=1, ~remove=1, ~insert=["foo"]), array),
+    eq,
+    (
+      // Even though original .splice returns an array with the removed items,
+      // the binding returns unit so there's no confusion about it mutating the original array.
+      (),
+      ["bar", "foo"],
+    ),
+  )
+}
+
+{
+  let array = []
+  array->Array.removeInPlace(0)
+  Test.run(__POS_OF__("removeInPlace - empty"), array, eq, [])
+}
+
+{
+  let array = ["Hello", "Hi", "Good bye"]
+  array->Array.removeInPlace(1)
+  Test.run(__POS_OF__("removeInPlace - from middle"), array, eq, ["Hello", "Good bye"])
+}