Add Dict.size

Author: DZakh

lib/es6/Stdlib_Dict.js

@@ -5,6 +5,10 @@ function $$delete$1(dict, string) {
   delete(dict[string]);
 }
 
+function size(dict) {
+  return Object.keys(dict).length;
+}
+
 function forEach(dict, f) {
   Object.values(dict).forEach(value => f(value));
 }
@@ -24,6 +28,7 @@ function mapValues(dict, f) {
 
 export {
   $$delete$1 as $$delete,
+  size,
   forEach,
   forEachWithKey,
   mapValues,

lib/js/Stdlib_Dict.js

@@ -5,6 +5,10 @@ function $$delete$1(dict, string) {
   delete(dict[string]);
 }
 
+function size(dict) {
+  return Object.keys(dict).length;
+}
+
 function forEach(dict, f) {
   Object.values(dict).forEach(value => f(value));
 }
@@ -23,6 +27,7 @@ function mapValues(dict, f) {
 }
 
 exports.$$delete = $$delete$1;
+exports.size = size;
 exports.forEach = forEach;
 exports.forEachWithKey = forEachWithKey;
 exports.mapValues = mapValues;

runtime/Stdlib_Dict.res

@@ -18,6 +18,8 @@ let delete = (dict, string) => {
 
 @val external keysToArray: dict<'a> => array<string> = "Object.keys"
 
+let size = dict => dict->keysToArray->Stdlib_Array.length
+
 @val external valuesToArray: dict<'a> => array<'a> = "Object.values"
 
 @val external assign: (dict<'a>, dict<'a>) => dict<'a> = "Object.assign"

runtime/Stdlib_Dict.resi

@@ -144,6 +144,25 @@ Console.log(keys) // Logs `["someKey", "someKey2"]` to the console
 @val
 external keysToArray: dict<'a> => array<string> = "Object.keys"
 
+/**
+`size(dictionary)` returns the number of key/value pairs in the dictionary.
+
+## Examples
+```rescript
+let dict = Dict.make()
+dict->Dict.size->assertEqual(0)
+
+dict->Dict.set("someKey", 1)
+dict->Dict.set("someKey2", 2)
+dict->Dict.size->assertEqual(2)
+
+// After deleting a key
+dict->Dict.delete("someKey")
+dict->Dict.size->assertEqual(1)
+```
+*/
+let size: dict<'a> => int
+
 /**
 `valuesToArray(dictionary)` returns an array of all the values of the dictionary.