support explicitly typed struct patterns

src/Convert/Struct.hs

@@ -292,6 +292,9 @@ convertExpr (struct @ (Struct _ fields [])) (Pattern itemsOrig) =
                         Just value = numberToInteger n
                         Right (Number n) = item
 
+convertExpr _ (Cast (Left t) expr@Pattern{}) =
+    Cast (Left t) $ convertExpr t expr
+
 convertExpr (Implicit _ []) expr = expr
 convertExpr (Implicit sg rs) expr =
     convertExpr (IntegerVector TBit sg rs) expr

src/Language/SystemVerilog/Parser/Parse.y

@@ -1266,6 +1266,7 @@ Expr :: { Expr }
   | Expr "?" Expr ":" Expr      { Mux $1 $3 $5 }
   | Expr "." Identifier         { Dot $1 $3 }
   | "'" "{" PatternItems "}"    { Pattern $3 }
+  | Expr "'" "{" PatternItems "}"{ Cast (Right $1) (Pattern $4) }
   | CastingType "'" "(" Expr ")" { Cast (Left  $1) $4 }
   | Expr        "'" "(" Expr ")" { Cast (Right $1) $4 }
   | "{" StreamOp StreamSize Concat "}" { Stream $2 $3         $4 }

test/core/struct_pattern_cast.sv

@@ -0,0 +1,12 @@
+module top;
+    typedef struct packed {
+        integer x;
+        byte y;
+    } S;
+    typedef struct packed {
+        byte x;
+        shortint y;
+        S z;
+    } T;
+    initial $display("%b", T'{ x: 1, y: 2, z: '{ x: 3, y: 4 } });
+endmodule

test/core/struct_pattern_cast.v

@@ -0,0 +1,3 @@
+module top;
+    initial $display("%b", { 8'd1, 16'd2, 32'd3, 8'd4 } );
+endmodule