Re: Pondering what rationale behind record type

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Tue, 10 May 2011 19:28:16 -0700 (PDT), Shark8 wrote:

> On May 10, 7:50�am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:
>>
>> What is the reason to name statements?
> 
> Simple: to aid in readability.
> I have a few rather deeply nested items where I'm tokenizing
> PostScript
> (due the rules of the language) and it is handy to have things like
> -- Case C, When C '<' =>
> Read_Character( C, Input );
> HANDLE_LT: -- less than
> if C = '<' then
>  Return Dictionary_Type;
> elsif C = '~' then
>  Return String_Type;
> else
>  Unread_Character( C, Input );
>  Return -- I forgot what the last case, just '<', was...
> end if HANDLE_LT;

The above should have been a "case", or better matching the input against a
token table with semantic callbacks doing things.

> There's even a few in blocks where I handle things like
> names ['identifiers'] vs. numbers; the PLRM defines a name
> as a string of "regular characters which cannot be interpreted
> as a string." This means that 23E4 is a number while 24F4 is
> a name as are $4, 2i3, @, 2^4 and so forth.

That is semantic analysis to me. No need to burden parser with that. You
parse 23E4 as a token and later interpret it as an identifier or number.

> It REALLY does help in sorting where you are in the decoding.

I don't think that large "if"s is a good style. No names may help that.
BTW, in your case "then", "else", "elsif" must carry the name of the "if"
they belong.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de