Merge branch 'upstream' into dfsg_clean20151220+dfsg

1 files changed, 16 insertions, 0 deletions

diff --git a/src/multimap_fn.sml b/src/multimap_fn.sml
new file mode 100644
index 00000000..3dab68a5
--- /dev/null
+++ b/src/multimap_fn.sml
@@ -0,0 +1,16 @@
+functor MultimapFn (structure KeyMap : ORD_MAP structure ValSet : ORD_SET) = struct
+    type key = KeyMap.Key.ord_key
+    type item = ValSet.item
+    type itemSet = ValSet.set
+    type multimap = ValSet.set KeyMap.map
+    val empty : multimap = KeyMap.empty
+    fun insertSet (kToVs : multimap, k : key, vs : itemSet) : multimap =
+        KeyMap.unionWith ValSet.union (kToVs, KeyMap.singleton (k, vs))
+    fun insert (kToVs : multimap, k : key, v : item) : multimap =
+        insertSet (kToVs, k, ValSet.singleton v)
+    fun findSet (kToVs : multimap, k : key) =
+        case KeyMap.find (kToVs, k) of
+            SOME vs => vs
+          | NONE => ValSet.empty
+    val findList : multimap * key -> item list = ValSet.listItems o findSet
+end