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Re: [PATCH] Class as a Feature (take four)

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Rafael Garcia-Suarez
December 15, 2008 14:44
Re: [PATCH] Class as a Feature (take four)
Message ID:
2008/12/15 chromatic <>:
> On Monday 15 December 2008 14:24:17 Rafael Garcia-Suarez wrote:
>> Sorry if I come late to this discussion, but what is the grand plan ?
>> Surely a lone class keyword is not that useful ? The following has to
>> be considered :
>> * syntax extensions in the class{} block (for example default
>> strictures, method keyword...)
>> * class attributes (like inheritance, or final-ness à la final classes
>> of Java, just to name some examples)
>> * a 3rd idea that I haven't seen yet here... define defaults for
>> method attributes ? (at BEGIN or CHECK time) Or interact with the
>> compilation in one way or another
> I think class BLOCK by itself is useful (descriptive and simpler syntax for
> compile-time package scoping and @ISA setting), but it's definitely a
> required feature before even considering at least the first element of your
> list.  Certainly it has more value than the similarly small syntax change of
> allowing 'method where 'sub' is today.

The work on the method keyword was not only a way to introduce named
parameters, but also aliasing and compile-time checking. (in a better
way than prototypes)

> Adding syntax extensions will be a much larger job, as it involves creating a
> new type of block and defining certain syntactic constructs which are only
> valid in the block.  (I couldn't see any easy way to use a literal token in
> the parser where currently you might use the WORD token, for example.)

You do that in the tokeniser, not in the parser. Perl's tokeniser is
scarily context-sensitive.

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