implement hashCode for maps in javascript

3 files changed, 20 insertions, 7 deletions

diff --git a/src/persistent-hash-map.mjs b/src/persistent-hash-map.mjs
index 8cdc023..c2a792c 100644
--- a/src/persistent-hash-map.mjs
+++ b/src/persistent-hash-map.mjs
@@ -568,7 +568,7 @@ function withoutCollision(root, _shift, _hash, key) {
     array: spliceOut(root.array, idx),
   };
 }
-function toArray(root, result) {
+function forEach(root, fn) {
   if (root === undefined) {
     return;
   }
@@ -580,10 +580,10 @@ function toArray(root, result) {
       continue;
     }
     if (item.type === ENTRY) {
-      result.push([item.k, item.v]);
+      fn(item.v, item.k);
       continue;
     }
-    toArray(item, result);
+    forEach(item, fn);
   }
 }
 /** Extra wrapper to keep track of map size */
@@ -592,6 +592,13 @@ export class PMap {
     this.root = root;
     this.size = size;
   }
+  hashCode() {
+    let h = 0;
+    forEach(this, (v, k) => {
+      h = (h + hashMerge(getHash(v), getHash(k))) | 0;
+    });
+    return h;
+  }
 }
 export function create() {
   return new PMap(undefined, 0);
@@ -645,7 +652,7 @@ export function entries(map) {
     return [];
   }
   const result = [];
-  toArray(map.root, result);
+  forEach(map.root, (v, k) => result.push([k, v]));
   return result;
 }
 export function __include_me() {
diff --git a/test/gleam/map_test.gleam b/test/gleam/map_test.gleam
index 2666579..34f3ee6 100644
--- a/test/gleam/map_test.gleam
+++ b/test/gleam/map_test.gleam
@@ -2,6 +2,8 @@ import gleam/map
 import gleam/option.{None, Some}
 import gleam/should
 import gleam/string
+import gleam/list
+import gleam/int
 
 pub fn from_list_test() {
   [#(4, 0), #(1, 0)]
@@ -103,6 +105,7 @@ pub fn keys_test() {
   [#("a", 0), #("b", 1), #("c", 2)]
   |> map.from_list
   |> map.keys
+  |> list.sort(string.compare)
   |> should.equal(["a", "b", "c"])
 }
 
@@ -110,6 +113,7 @@ pub fn values_test() {
   [#("a", 0), #("b", 1), #("c", 2)]
   |> map.from_list
   |> map.values
+  |> list.sort(int.compare)
   |> should.equal([0, 1, 2])
 }
 
@@ -189,11 +193,12 @@ pub fn fold_test() {
   |> map.fold(0, add)
   |> should.equal(6)
 
-  let concat = fn(acc, k, _) { string.append(acc, k) }
+  let prepend = fn(acc, k, _) { list.prepend(acc, k) }
 
   dict
-  |> map.fold("", concat)
-  |> should.equal("abcd")
+  |> map.fold([], prepend)
+  |> list.sort(string.compare)
+  |> should.equal(["a", "b", "c", "d"])
 
   map.from_list([])
   |> map.fold(0, add)
diff --git a/test/gleam/set_test.gleam b/test/gleam/set_test.gleam
index aae5256..123dc43 100644
--- a/test/gleam/set_test.gleam
+++ b/test/gleam/set_test.gleam
@@ -70,6 +70,7 @@ pub fn filter_test() {
   |> set.from_list()
   |> set.filter(for: int.is_even)
   |> set.to_list
+  |> list.sort(int.compare)
   |> should.equal([4, 6, 44])
 }