[Lazarus] Easiest way to "case" strings

[Marco van de Voort]

On Thu, Mar 26, 2009 at 11:06:03AM +0000, Martin Friebe wrote:
> Marco van de Voort wrote:
> >> Since string was introduced as built-in "scalar" type with defined
> >> equality, lack of 'case' support can be viewed as a design bug.
> >
> > I don't see string as a scalar type. It is an array or complex type IMHO.
> anyway, best argument(s) I think I saw for string case so far:
> 
> 1) Readability.
> I think it is true, 10 or more lines of  IF...ELSE IF ... can obscure 
> readability.
> 
> I wonder how many of the cases where this happens, actually are truly 
> needed?
> How many of them could have used a simpler data-type, and how many of 
> them would have wanted are more specialized approach such as LEX?

Exactly. Also the alternative presented wasn't if then nesting, but rather a
library routine that is like a POS for array of string.
 
> 2) Optimizations:
> If string-case existed, the compiler could optimize the code, by using 
> hashes or tree like lookup.

This can be done better by the library procedure, since that is more easily
changable than language. Including hash algorithm etc.
 
> While that's true, I wonder if that is really a good  idea. It would be 
> the first step of embedding LEX/YACC into the language.
> One may say this is of benefits for beginners, because the need to learn 
> less about other tools; the truth is, discouraging a beginner from 
> learning has no long time benefit.

I doubt this is so good for the beginner. Nearly no tokenizer works this
way.
 
> I think if you have large enough string casings and need the speed, you 
> sghould use the tools specially made for this.

If the need was really this high, probably lazarus already would have a
lexer/yacc like app internal, and you could edit grammars in a comfortable
editor, with diagramming and consistency checking support.

It is so horrible little subset of a parser, it is next to useless, except
for the last poor guy coming from basic that wants to "streamline/modernize" his
nested if..then's without really thinking about the problem.