Add signatures

1 files changed, 22 insertions, 2 deletions

diff --git a/Parser.sml b/Parser.sml
index 8a1e1f3..a967880 100644
--- a/Parser.sml
+++ b/Parser.sml
@@ -619,9 +619,28 @@ struct
   val rec strdec : Syntax.dec option parser = fn st =>
       ((reserved "structure" >>
       bind identifier (fn strID =>
+      bind
+        (((reserved ":" <|> reserved ":>") >>
+          SOME <$> identifier)
+        <|> const NONE)
+        (fn s =>
       reserved "=" >>
       bind structExpr (fn str =>
-      const (SOME (Syntax.DStruct (strID, str))))))
+      const (SOME (Syntax.DStruct (strID, s, str)))))))
+  <|> (reserved "signature" >>
+      bind identifier (fn sigID =>
+      reserved "=" >>
+      reserved "sig" >>
+      bind
+        (many
+          (reserved "val" >>
+          bind identifier (fn id =>
+          reserved ":" >>
+          bind parseType (fn ty =>
+          const (id, ty)))))
+        (fn bindings =>
+      reserved "end" >>
+      const (SOME (Syntax.DSig (sigID, bindings))))))
   <|> dec) st
   and structExpr : Syntax.structExpr parser = fn st =>
         ((reserved "struct" >>
@@ -655,7 +674,8 @@ struct
         Syntax.DFun (f, map (fn (args, body) => (map (fixPatConstructors constructors) args, fixConstructors constructors body)) arms)
     | fixDecConstructors _ (decl as Syntax.DDatatype _) = decl
     | fixDecConstructors _ (decl as Syntax.DType _) = decl
-    | fixDecConstructors constructors (Syntax.DStruct (name, str)) = Syntax.DStruct (name, fixStructExprConstructors constructors str)
+    | fixDecConstructors constructors (Syntax.DStruct (name, s, str)) = Syntax.DStruct (name, s, fixStructExprConstructors constructors str)
+    | fixDecConstructors constructors (s as Syntax.DSig _) = s
 
   and fixStructExprConstructors (constructors : unit StringMap.map) (Syntax.SStruct decls) : Syntax.structExpr =
         let val constructors = ref constructors in