Why is an enumerated type requiring the type name before the constants?

[PiedSoftware 2]

Hi, I was surprised when a simple bit of code did not compile for me. I am using Delphi 10.1, and TEditCharCase is defined in System.UITypes thus:
 

  TEditCharCase = (ecNormal, ecUpperCase, ecLowerCase);

I have a property of that type in a class TMapItem declared thus:
 

property CharCase: TEditCharCase read fCharCase write fCharCase;

Control clicking on TEditCharCase takes me straight to that line in UITypes.
But when I wrote this innocent looking code:          

 case mapItem.CharCase of
    ecNormal:    expr := value;
    ecUpperCase: expr := value.ToUpper;
    ecLowerCase: expr := value.ToLower;
end;

it refused to compile, saying "E2003 Undeclared identifier: 'ecLowerCase'", etc for the 3 enumerated constants.

But I got it to compile by prefixing the constants with the type name, thus:

 case mapItem.CharCase of
   TEditCharCase.ecNormal:    expr := value;
   TEditCharCase.ecUpperCase: expr := value.ToUpper;
   TEditCharCase.ecLowerCase: expr := value.ToLower;
 end;

This is strange. There are lots of places of enumerated types that don't need to have the type prefixed. 

Can anyone explain this?

TIA
Mark Patterson

[David Heffernan 2293]

These doc links explain it

 

Simple Types (Delphi) - RAD Studio (embarcadero.com)

 

Scoped Enums (Delphi) - RAD Studio (embarcadero.com)

Edited December 8, 2020 by David Heffernan

[Guest]

when occurr the "conflict" between names (any object/vars etc...) it's necessary identify "where it from came"  (what unit, what record, etc...) the value, then, you need use a "NameSpace" for any divergence!

For that, it's necessary always pay attention when "give a name" for a object/var etc...

You can find some examples in source code from RAD!

 

for example:

Quote

if unitMyRecords.mapItem.CharChase = expr  then...

 

other thing: here you're already using a "namespace" way:  using "case" 

 case mapItem.CharCase of
   TEditCharCase.ecNormal
...

hug

Edited December 8, 2020 by Guest

[PiedSoftware 2]

17 hours ago, David Heffernan said:

These doc links explain it

 

Simple Types (Delphi) - RAD Studio (embarcadero.com)

 

Scoped Enums (Delphi) - RAD Studio (embarcadero.com)

Thanks, David. I had a look at the code of UITypes.pas, and there at the top, as brazen as anything, is
 

{$SCOPEDENUMS ON}

I learned something new. And only been doing Delphi since 1995.

[PiedSoftware 2]

I noticed in the library source code that some of the uses of TEditCharChase constants were not prefixed with the type. For example, in DbCtrls there is this:
 

        case CharCase of
          ecUpperCase: S := AnsiUpperCase(S);
          ecLowerCase: S := AnsiLowerCase(S);
        end;

When you ctrl-click the constants there you are sent to a line in StdCtrls that is part of this sequence of declarations:

const
{ Editors common support }
  ecNormal	= System.UITypes.TEditCharCase.ecNormal;
  ecUpperCase	= System.UITypes.TEditCharCase.ecUpperCase;
  ecLowerCase	= System.UITypes.TEditCharCase.ecLowerCase;

type
  TEditCharCase = System.UITypes.TEditCharCase;

So, some people seem to want to work around the SCOPEDENUMS.