Free Pascal: detect "is word char" for WideChar

Question

I use code

Result:=
((ch>='0') and (ch<='9')) or
((ch>='a') and (ch<='z')) or
((ch>='A') and (ch<='Z')) or
(ch='_');

it detects ok AnsiChar; how to detect "if char letter or digit" for WideChar?

Answer 1

I guess there's no simple way to solve this. What's your definition of a letter? Ω (omega) is a letter? is it just a symbol? You would have to manually decide what is a letter and what is not. You could make a big case statement that determines whether a char is alpha numeric or not...

function is_alpha_num(ch : widechar) : boolean;
begin
  case ch of
    #$0030..#$0039, // '0'..'9'                                                 
    #$0041..#$005A, // 'A'..'Z'                                                 
    #$0061..#$007A, // 'a'..'z'                                                 
    // need to define the rest here...                                          
    #$FF21..#$FF3A // 'Ａ'..'Ｚ'                                                
    : result := true;
   else result := false;
  end;
end;