--- a/modules/list.tp	Fri Aug 01 18:56:39 2014 -0700
+++ b/modules/list.tp	Fri Aug 01 18:56:50 2014 -0700
@@ -4,6 +4,8 @@
 		empty? <- { true }
 		fold:with <- :acc :fun { acc }
 		foldr:with <- :acc :fun { acc }
+		filter <- :pred { self }
+		foreach <- :self fun { self }
 		map <- :fun { self }
 		| <- :val {
 			list node: val withTail: self
@@ -38,6 +40,11 @@
 				foldr:with <- :acc fun {
 					fun: (_tail foldr: acc with: fun) _val
 				}
+				filter <- :pred {
+					reverse: (fold: [] with: :acc el {
+						if: (pred: el) { el | acc } else: { acc }
+					})
+				}
 				map <- :fun {
 					node: (fun: _val) withTail: (_tail map: fun)
 				}