src/main/wacc/typeChecker.scala

@@ -95,28 +95,27 @@ object typeChecker {
       )
     case Assign(lhs, rhs) =>
       val lhsTy = checkValue(lhs, Constraint.Unconstrained)
-      checkValue(rhs, Constraint.Is(lhsTy, s"assignment must have type $lhsTy")) match {
-        case ? =>
+      (lhsTy, checkValue(rhs, Constraint.Is(lhsTy, s"assignment must have type $lhsTy"))) match {
+        case (?, ?) =>
           ctx.error(
             Error.SemanticError(lhs.pos, "assignment with both sides of unknown type is illegal")
           )
         case _ => ()
       }
-    case Read(lhs) =>
-      val lhsTy = checkValue(lhs, Constraint.Unconstrained)
-      lhsTy match {
+    case Read(dest) =>
+      checkValue(dest, Constraint.Unconstrained) match {
         case ? =>
           ctx.error(
-            Error.SemanticError(lhs.pos, "cannot read into a destination with an unknown type")
+            Error.SemanticError(dest.pos, "cannot read into a destination with an unknown type")
           )
-        case _ =>
-          lhsTy.satisfies(
+        case destTy =>
+          destTy.satisfies(
             Constraint.IsEither(
               KnownType.Int,
               KnownType.Char,
               "read must be applied to an int or char"
             ),
-            lhs.pos
+            dest.pos
           )
       }
     case Free(lhs) =>