Add map_for_each and map_group_by to utility library.

1 files changed, 29 insertions, 0 deletions

diff --git a/public/common/util.js b/public/common/util.js
index c14d406..7f5459e 100644
--- a/public/common/util.js
+++ b/public/common/util.js
@@ -279,6 +279,11 @@ function map_delete(map, key) {
 	}
 }
 
+function map_for_each(map, f) {
+	for (let i = 0; i < map.length; i += 2)
+		f(map[i], map[i+1])
+}
+
 function object_diff(a, b) {
 	if (a === b)
 		return false
@@ -327,3 +332,27 @@ function object_group_by(items, callback) {
 	}
 	return groups
 }
+
+function map_group_by(items, callback) {
+	let groups = []
+	if (typeof callback === "function") {
+		for (let item of items) {
+			let key = callback(item)
+			let arr = map_get(groups, key)
+			if (arr)
+				arr.push(item)
+			else
+				map_set(groups, key, [ item ])
+		}
+	} else {
+		for (let item of items) {
+			let key = item[callback]
+			let arr = map_get(groups, key)
+			if (arr)
+				arr.push(item)
+			else
+				map_set(groups, key, [ item ])
+		}
+	}
+	return groups
+}