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Postings from November 2004
Matthew Walton wrote:
> James Mastros wrote:
>> Larry Wall wrote:
>>
>>> On Fri, Nov 26, 2004 at 07:32:58AM +0300, Alexey Trofimenko wrote:
>>> : ah, I forget, how could I do qx'echo $VAR' in Perl6? something like
>>> : qx:noparse 'echo $VAR' ?
>>>
>>> I think we need two more adverbs that add the special features of qx
>>> and qw,
>>> so that you could write that:
>>>
>>> q:x/echo $VAR/
>>>
>>> where ordinary qx/$cmd/ is short for
>>>
>>> qq:x/$cmd/
>> I think I'd like that much better if we consider execution and
>> word-splitting to be the primary operations, and interpolation and
>> noninterpolation the adverbial modifiers then the other way around,
>> making that qx:q/echo $VAR/ or qx:qq/$cmd/.
especially because adverbs are meant to say "how to do" rather than "what
to do", aren't they?
>> OTOH, I expect backticks to be rare enough that I wouldn't mind writing
>> use Spawn 'spawn';
>> spawn :capture :wait ($cmd);
>> spawn :capture :wait ('echo $VAR');
> Although I'm masochistic enough that I don't mind the idea of always
> having to do execution with qx//, qx:q// or qx:qq// (running with other
> suggestions, I'd guess that would be non-interpolating execution, then
> the same again more explicitly, then interpolating execution) but I do
> like the idea of spawn.
hm.. qx:q// qx:qq//
...compare with:
qx q// qx qq//
so there's no need in adverbs. But we have no need in qx either. Why to
introduce (or REintroduce) something if we have something similar already?
$captured = system :capture q/cmd../;
or maybe even:
(code=>$code, out=>$captured, err=>$err) = system qq/cmd/;
or maybe even(!)
$captured = slurp qq/$cmd |/;
> Kind of removes the idea of pulling in the output of other programs as a
> fundamental part of the language though, for that it's nice to have an
> executing, capturing quote. Perhaps an adverb to qx that makes it behave
> like system() - I don't think it'd be a good idea to provide one that
> makes it behave like exec(), although perhaps other people do.
I haven't that long unix background, and spawning processes is a very
*fat* operation for me.. maybe after year or two I'll change my point of
view, but for now I would be pretty happy with a 'slurp' variant. IMHO,
spawning processes has nothing to do with other quoters, and perl already
went far away from shells.
but talking about oneliners and short shell-like scripts, where `` is
pretty useful.. hm.. things good for oneliners are rarely as good for
larger programs, and vice versa. Of course, Perl5 proves opposite, but
Perl6 tends to be a little more verbose, and even in Perl5 we use quite
different "toolbox" and style for mentioned above. Why not to make an
average sized module of various "shortcut" grammars, with a very short
name ("x", f.e.), with defaults to export :all, so we could just do
perl -Mx -e 'print `echo this is a perl5qx`'
even if `` would be taken for something more useful in Perl6,
and still be able to import only something useful for our larger program
with
use x qw/:perl5qx/;