Add an infinite set collection type.

1 files changed, 5 insertions, 1 deletions

diff --git a/Source/Dafny/Printer.cs b/Source/Dafny/Printer.cs
index 0259f12c..cdcdb9e8 100644
--- a/Source/Dafny/Printer.cs
+++ b/Source/Dafny/Printer.cs
@@ -1346,7 +1346,11 @@ namespace Microsoft.Dafny {
 

       } else if (expr is DisplayExpression) {

         DisplayExpression e = (DisplayExpression)expr;

-        if (e is MultiSetDisplayExpr) wr.Write("multiset");

+        if (e is MultiSetDisplayExpr) {

+          wr.Write("multiset");

+        } else if (e is SetDisplayExpr && !((SetDisplayExpr)e).Finite) {

+          wr.Write("iset");

+        }

         wr.Write(e is SetDisplayExpr || e is MultiSetDisplayExpr ? "{" : "[");

         PrintExpressionList(e.Elements, false);

         wr.Write(e is SetDisplayExpr || e is MultiSetDisplayExpr ? "}" : "]");