Re: A common base exception object for Perl - RFC

[Pete Jordan <pjordan1@email.mot.com>]

Larry Wall wrote:

> The trouble is that the - is really redundant with the =>.  I've been
> thinking for a long time that there ought to be a way to determine
> whether a given argument in a list was followed by a => rather than a
> comma.  Then you could write a subroutine that processes an arbitrary
> list of single arguments followed by an arbitrary list of paired
> arguments.  Or a prototype of % could guarantee that you don't get out
> of sync.  (At the moment, a prototype of % is treated just like @.)

This would be a good usage for the % template. How would the separation
between initial-list and trailing-key-value-pair-list be implemented in
the called subroutine? The latter could end up in C<%_>, I suppose, if I
actually /want/ a hash in my subroutine, but what if I wish to avoid
that overhead? How could a key-value pair be identified in C<@_>?
Especially as whatever is done must be backwards compatible.

I suppose a single-initial-optional-scalar could be an indirect object:

	sub foo ($?%) {
	  my ($text, @options)=@_; # or ($text, %options)
	}

	foo bar=>'baz'; # $text undefined in foo
	foo 'plinth' architrave=>1, elf=>'split';

Pete
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References to:

Larry Wall <larry@wall.org>

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