I think the issue is that bare vars don't interpolate anymore, but
they still have sigils of their own, so adding to the default interp
syntax is too noisy: ${$var} is not really much improvement over
${\(expr)}.
- Original message -
I am not quite sure of all the implications in t...
On 12/20/07, Adriano Ferreira <[EMAIL PROTECTED]> wrote:
> On Dec 20, 2007 1:48 AM, Michael G Schwern <[EMAIL PROTECTED]> wrote:
> > I was reading an article about Perl 6, I forget which one, and it happened
> to
> > mention that code can be interpolated inside double quoted strings.
> That's
> > one thing, my concern is with the selected syntax.
> >
> > say "foo { 1+1 }"; # "foo 2"
> >
> > The {...} construct seems far too common one in normal text to be given
> > special meaning. One data point is to do a google code search for "{ in
> Perl
> > 5. It comes up with quite a lot.
> >
> http://www.google.com/codesearch?hl=en&lr=&q=%5C%22%5C%7B+lang%3Aperl&btnG=Search
> >
> > Another concern is embedded YAML.
> >
> > $yaml = "{ $key: 42 }"; # syntax error in Perl 6
> >
> > Finally, it chokes on unbalanced braces adding another trap for users.
> >
> > I'm concerned this will lead to a lot of unsightly backwhacking or having
> to
> > be more careful about what type of string you're using.
> >
> > What about ${} and @{} instead? ${} would execute in scalar context and
> @{}
> > in list. They're just cleaned up versions of the successful, but ugly,
> Perl 5
> > idioms ${\(...)} and @{[...]} idioms. They make use of an existing
> > interpolated character so there's no additional load on the programmer.
> >
> > ${} and @{} already have interpolated meanings in Perl 5 but not in Perl
> 6.
>
> I am not quite sure of all the implications in the design of quoting
> constructs (which is detailed in Synopsis 02 -
> http://perlcabal.org/syn/S02.html). But it seems Larry anticipated
> mechanisms to handle all the cases you mentioned.
>
> For instance, while {...} expressions do interpolate by default as in
>
> > say "foo { 1+1 }"; # "foo 2"
>
> but that can be stopped by using a quoting construct plus an adverb. I
> think that should be something like
>
> say Q :!c <foo { 1 + 1}>; # "foo { 1 + 1 }"
>
> Also, the sigils can interpolate just the way you said, but using ()
> rather than braces (which is consistent to how they are used in other
> expressions of the language).
>
> It is all there somewhere in Section "Literals" of Synopsis 02
> (http://perlcabal.org/syn/S02.html#Literals). More specifically, look
> for the item that starts with "In addition to q and qq, there is now
> the base form Q".
>
> Kind regards,
> Adriano Ferreira
>
> > --
> > ...they shared one last kiss that left a bitter yet sweet taste in her
> > mouth--kind of like throwing up after eating a junior mint.
> > -- Dishonorable Mention, 2005 Bulwer-Lytton Fiction Contest
> > by Tami Farmer
> >
> >
>
--
Mark J. Reed <[EMAIL PROTECTED]>
