[fpc-pascal] Case based on type

[Marco van de Voort]

In our previous episode, Sven Barth said:
> === example end ===
> 
> Alternatively if you don't need to check the hierarchy, but can live 
> with an exact match you can do this:
> 
> === example begin ===
> 
> procedure checkLibrariesAndConnect(db: TSQLConnection);
> begin
>    case LowerCase(db.ClassName) of
>      // Note: .ClassName won't work here
>      'TPQConnection': ...;
>      'TIBConnection': ...;
>    end;
> end;

var typ : TCLass;

begin
  typ:=db.classtype;  found:=false;
  while not found and assigned(typ) do
    begin
       case lowercase(typ.classname)
         ..  // must set found=true on match or break.
       end;
      typ:=typ.classparent;
    end;