[NF] Retype conditional array expressions.

- When doing branch selection on if-expressions where the branches have
  different dimensions, also do branch selection on the type of the
  if-expression.

Author: perost

OMCompiler/Compiler/NFFrontEnd/NFEvalConstants.mo

@@ -234,8 +234,10 @@ algorithm
                Dimension.toStringList(Type.arrayDims(Expression.typeOf(fb)), brackets = false)}, info);
             fail();
           end if;
+
+          outExp := evaluateExpTraverser(if cond.value then tb else fb, info);
         then
-          evaluateExpTraverser(if cond.value then tb else fb, info);
+          (outExp, true);
 
       else
         algorithm
@@ -252,7 +254,10 @@ algorithm
       // Only evaluate constants in and return one of the branches if the
       // condition is a literal boolean value.
       case Expression.BOOLEAN()
-        then evaluateExpTraverser(if cond.value then tb else fb, info);
+        algorithm
+          outExp := evaluateExpTraverser(if cond.value then tb else fb, info);
+        then
+          (outExp, true);
 
       // Otherwise evaluate constants in both branches and return the whole
       // if-expression.

OMCompiler/Compiler/NFFrontEnd/NFExpression.mo

@@ -4340,6 +4340,7 @@ public
     () := match exp
       local
         list<Dimension> dims;
+        Type ty;
 
       case RANGE()
         algorithm
@@ -4354,7 +4355,17 @@ public
         then
           ();
 
-      else ();
+      else
+        algorithm
+          ty := typeOf(exp);
+
+          if Type.isConditionalArray(ty) then
+            ty := Type.simplifyConditionalArray(ty);
+            exp := setType(ty, exp);
+          end if;
+        then
+          ();
+
     end match;
   end retype;
 

OMCompiler/Compiler/NFFrontEnd/NFType.mo

@@ -345,6 +345,22 @@ public
     end if;
   end isMatchedBranch;
 
+  function simplifyConditionalArray
+    input Type ty;
+    output Type outType;
+  algorithm
+    outType := match ty
+      case CONDITIONAL_ARRAY()
+        then match ty.matchedBranch
+            case Branch.TRUE then ty.trueType;
+            case Branch.FALSE then ty.falseType;
+            else ty;
+          end match;
+
+      else ty;
+    end match;
+  end simplifyConditionalArray;
+
   function isVector
     "Return whether the type is a vector type or not, i.e. a 1-dimensional array."
     input Type ty;