[NF] Fix type when expanding unary expressions.

Belonging to [master]:
  - #2576

Author: perost

Compiler/NFFrontEnd/NFExpandExp.mo

@@ -761,11 +761,14 @@ public
     input Operator op;
     output Expression outExp;
     output Boolean expanded;
+  protected
+    Operator scalar_op;
   algorithm
     (outExp, expanded) := expand(exp);
+    scalar_op := Operator.scalarize(op);
 
     if expanded then
-      outExp := Expression.mapArrayElements(outExp, function makeUnaryOp(op = op));
+      outExp := Expression.mapArrayElements(outExp, function makeUnaryOp(op = scalar_op));
     end if;
   end expandUnary;
 
@@ -815,11 +818,14 @@ public
     input Operator op;
     output Expression outExp;
     output Boolean expanded;
+  protected
+    Operator scalar_op;
   algorithm
     (outExp, expanded) := expand(exp);
+    scalar_op := Operator.scalarize(op);
 
     if expanded then
-      outExp := Expression.mapArrayElements(outExp, function makeLogicalUnaryOp(op = op));
+      outExp := Expression.mapArrayElements(outExp, function makeLogicalUnaryOp(op = scalar_op));
     else
       outExp := exp;
     end if;

Compiler/NFFrontEnd/NFOperator.mo

@@ -195,6 +195,12 @@ public
     op.ty := ty;
   end setType;
 
+  function scalarize
+    input output Operator op;
+  algorithm
+    op.ty := Type.arrayElementType(op.ty);
+  end scalarize;
+
   function symbol
     input Operator op;
     input String spacing = " ";