Dict: add forEach, forEachWithKey, mapValues (rescript-lang#181)

* Add Dict.forEach and Dict.forEachWithKey

* Add Dict.mapValues

* Update CHANGELOG

Author: BartSchuurmans

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Next version
 
 - BREAKING: Fixes the type of `RegExp.Result.t` to be `array<option<string>>` instead of `array<string>`. https://github.com/rescript-association/rescript-core/pull/233.
+- Add `Dict.forEach`, `Dict.forEachWithKey` and `Dict.mapValues` https://github.com/rescript-association/rescript-core/pull/181
 
 ## 0.7.0
 

src/Core__Dict.mjs

@@ -5,7 +5,30 @@ function $$delete$1(dict, string) {
   delete(dict[string]);
 }
 
+function forEach(dict, f) {
+  Object.values(dict).forEach(function (value) {
+        f(value);
+      });
+}
+
+function forEachWithKey(dict, f) {
+  Object.entries(dict).forEach(function (param) {
+        f(param[1], param[0]);
+      });
+}
+
+function mapValues(dict, f) {
+  var target = {};
+  forEachWithKey(dict, (function (value, key) {
+          target[key] = f(value);
+        }));
+  return target;
+}
+
 export {
   $$delete$1 as $$delete,
+  forEach ,
+  forEachWithKey ,
+  mapValues ,
 }
 /* No side effect */

src/Core__Dict.res

@@ -23,3 +23,19 @@ let delete = (dict, string) => {
 @val external assign: (t<'a>, t<'a>) => t<'a> = "Object.assign"
 
 @val external copy: (@as(json`{}`) _, t<'a>) => t<'a> = "Object.assign"
+
+let forEach = (dict, f) => {
+  dict->valuesToArray->Core__Array.forEach(value => f(. value))
+}
+
+let forEachWithKey = (dict, f) => {
+  dict->toArray->Core__Array.forEach(((key, value)) => f(. value, key))
+}
+
+let mapValues = (dict, f) => {
+  let target = make()
+  dict->forEachWithKey((. value, key) => {
+    target->set(key, f(. value))
+  })
+  target
+}

src/Core__Dict.resi

@@ -190,3 +190,47 @@ Console.log2(dict->Dict.keysToArray, dict2->Dict.keysToArray)
 */
 @val
 external copy: (@as(json`{}`) _, t<'a>) => t<'a> = "Object.assign"
+
+/**
+`forEach(dictionary, f)` iterates through all values of the dict.
+
+> Please note that this is *without the keys*, just the values. If you need the key as well, use `Dict.forEachWithKey`.
+
+## Examples
+```rescript
+let dict = Dict.fromArray([("key1", "value1"), ("key2", "value2")])
+
+dict->Dict.forEach(value => {
+  Console.log(value)
+})
+```
+*/
+let forEach: (t<'a>, (. 'a) => unit) => unit
+
+/**
+`forEachWithKey(dictionary, f)` iterates through all values of the dict, including the key for each value.
+
+## Examples
+```rescript
+let dict = Dict.fromArray([("key1", "value1"), ("key2", "value2")])
+
+dict->Dict.forEachWithKey((value, key) => {
+  Console.log2(value, key)
+})
+```
+*/
+let forEachWithKey: (t<'a>, (. 'a, string) => unit) => unit
+
+/**
+`mapValues(dictionary, f)` returns a new dictionary with the same keys, and `f` applied to each value in the original dictionary.
+
+## Examples
+
+```rescript
+let dict = Dict.fromArray([("key1", 1), ("key2", 2)])
+
+dict->Dict.mapValues(v => v + 10)->Dict.toArray // [("key1", 11), ("key2", 12)]
+dict->Dict.mapValues(Int.toString)->Dict.toArray // [("key1", "1"), ("key2", "2")]
+```
+*/
+let mapValues: (t<'a>, (. 'a) => 'b) => t<'b>