Fix issue #79. Allow tuple pattern matching with parenthesis only.

1 files changed, 20 insertions, 1 deletions

diff --git a/Source/Dafny/Parser.cs b/Source/Dafny/Parser.cs
index d0924169..162e23a3 100644
--- a/Source/Dafny/Parser.cs
+++ b/Source/Dafny/Parser.cs
@@ -2934,7 +2934,7 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			Ident(out id);

 			Expect(48);

 			arguments = new List<CasePattern>(); 

-			if (la.kind == 1) {

+			if (la.kind == 1 || la.kind == 48) {

 				CasePattern(out pat);

 				arguments.Add(pat); 

 				while (la.kind == 21) {

@@ -2945,6 +2945,25 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo
 			}

 			Expect(49);

 			pat = new CasePattern(id, id.val, arguments); 

+		} else if (la.kind == 48) {

+			Get();

+			id = t;                                                           

+			arguments = new List<CasePattern>(); 

+			

+			if (la.kind == 1 || la.kind == 48) {

+				CasePattern(out pat);

+				arguments.Add(pat); 

+				while (la.kind == 21) {

+					Get();

+					CasePattern(out pat);

+					arguments.Add(pat); 

+				}

+			}

+			Expect(49);

+			theBuiltIns.TupleType(id, arguments.Count, true); // make sure the tuple type exists

+			string ctor = BuiltIns.TupleTypeCtorName;  //use the TupleTypeCtors

+			pat = new CasePattern(id, ctor, arguments); 

+			

 		} else if (la.kind == 1) {

 			IdentTypeOptional(out bv);

 			pat = new CasePattern(bv.tok, bv);