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 +302,26 @@ 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"
 
+/**
+`removeInPlace(array, index)` removes the item at the specified `index` from `array`.
+
+Beware this will *mutate* the array.
+
+## Examples
+
+```rescript
+let array = []
+array->Array.removeInPlace(0)
+assertEqual(array, []) // Removing from an empty array does nothing
+
+let array2 = ["Hello", "Hi", "Good bye"]
+array2->Array.removeInPlace(1)
+assertEqual(array2, ["Hello", "Good bye"]) // Removes the item at index 1
+```
+ */
+@send
+external removeInPlace: (array<'a>, int, @as(1) _) => unit = "splice"
+
 @send external with: (array<'a>, int, 'a) => array<'a> = "with"
 
 /**

tests/analysis_tests/tests/src/expected/Completion.res.txt

@@ -508,6 +508,12 @@ Path Array.
     "tags": [],
     "detail": "(array<'a>, int) => option<'a>",
     "documentation": {"kind": "markdown", "value": "\n`get(array, index)` returns the element at `index` of `array`.\n\nReturns `None` if the index does not exist in the array. Equivalent to doing `array[index]` in JavaScript.\n\n## Examples\n\n```rescript\nlet array = [\"Hello\", \"Hi\", \"Good bye\"]\n\narray\n->Array.get(0)\n->assertEqual(Some(\"Hello\"))\n\narray\n->Array.get(3)\n->assertEqual(None)\n```\n"}
+  }, {
+    "label": "removeInPlace",
+    "kind": 12,
+    "tags": [],
+    "detail": "(array<'a>, int) => unit",
+    "documentation": {"kind": "markdown", "value": "\n`removeInPlace(array, index)` removes the item at the specified `index` from `array`.\n\nBeware this will *mutate* the array.\n\n## Examples\n\n```rescript\nlet array = []\narray->Array.removeInPlace(0)\nassertEqual(array, []) // Removing from an empty array does nothing\n\nlet array2 = [\"Hello\", \"Hi\", \"Good bye\"]\narray2->Array.removeInPlace(1)\nassertEqual(array2, [\"Hello\", \"Good bye\"]) // Removes the item at index 1\n```\n "}
   }, {
     "label": "pushMany",
     "kind": 12,

tests/analysis_tests/tests/test.sh

@@ -22,9 +22,9 @@ reset='\033[0m'
 
 diff=$(git ls-files --modified src/expected)
 if [[ $diff = "" ]]; then
-  printf "${successGreen}✅ No unstaged tests difference.${reset}\n"
+  printf "${successGreen}✅ No analysis_tests snapshot changes detected.${reset}\n"
 else
-  printf "${warningYellow}⚠️ There are unstaged differences in tests/! Did you break a test?\n${diff}\n${reset}"
+  printf "${warningYellow}⚠️ The analysis_tests snapshot doesn't match. Double check that the output is correct and run 'make analysis_tests' if you get the error in CI\n${diff}\n${reset}"
   git --no-pager diff src/expected
   exit 1
 fi

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",
+    137,
+    22,
+    45
+  ],
+  "removeInPlace - empty"
+], array$2, eq, []);
+
+let array$3 = [
+  "Hello",
+  "Hi",
+  "Good bye"
+];
+
+array$3.splice(1, 1);
+
+Test.run([
+  [
+    "Core_ArrayTests.res",
+    143,
+    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"])
+}