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Postings from September 2000
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=head1 TITLE
Allow keywords in sub prototypes
=head1 VERSION
Maintainer: Simon Cozens <simon@brecon.co.uk>
Date: 25 Sep 2000
Mailing List: perl6-language-subs@perl.org
Number: 309
Version: 1
Status: Developing
=head1 ABSTRACT
This is a general way of helping people create their own syntax.
=head1 DESCRIPTION
The perlsub documentation talks about the use of C<&> in a prototype:
The interesting thing about C<&> is that you can generate new syntax
with it, provided it's in the initial position
Well, you can, within limits. But it would fix a lot of things that
people believe they want if you could B<really> define your own syntax.
sub apply (& to @) {
...
}
apply { this } to @that;
=head1 IMPLEMENTATION
This becomes a B<little> bit of a nightmare for the parser; but TeX
manages it.
In fact, it's not as hard as it looks, because you still know what
you're expecting: after a block, we want some whitespace and the
keyword "to", then some more whitespace and an array. Since we may well
be having the parser dynamically modifiable, this should be easy. Yeah,
right.
=head1 REFERENCES
RFC 57: Subroutine prototypes and parameters
L<perlsub|perlsub>
RFC ??: Byte-compiled Parser
RFC ??:C<use syntax>