Re: When scoping
On 5/4/05, Larry Wall [EMAIL PROTECTED] wrote:
To get the other behavior, you have to say one of:
given hello {
when /hello/ {
say One;
when /hello/ { say Two; continue; }
when /hello/ { say Three; continue; }
continue;
}
say Four;
}
given hello {
when /hello/ {
say One;
say Two when /hello/;
say Three when /hello/;
continue;
}
say Four;
}
given hello {
when /hello/ {
say One;
if /hello/ { say Two; }
if /hello/ { say Three; }
continue;
}
say Four;
}
That seems like enough WTDI.
Not quite. There's also the way that I have it in the pugs IRC bot:
given hello {
when /hello/ {
given $_ {
say One;
when /hello/ { say Two }
when /hello/ { say Three }
}
}
say Four;
}
Which I actually like the best. If only it weren't so heavily indented.
Hmmm, maybe I should go implement Acme::Whiven:
given hello {
whiven /hello/ {
when /hello/ {...}
...
}
}
Luke
Re: When scoping
On Wed, May 04, 2005 at 11:00:46PM -0700, David Wheeler wrote:
: On May 4, 2005, at 22:31 , Larry Wall wrote:
:
: given hello {
: when /hello/ {
: say One;
: if /hello/ { say Two; }
: if /hello/ { say Three; }
: continue;
: }
: say Four;
: }
:
: Is there no more
:
: say Two if /hello/;
:
: ?
You must have missed the implied ... at the end of my list of other WTDI.
You can also do any of:
say Two if /hello/;
/hello/ say Two;
/hello/ and say Two;
/hello/ ?? say Two :: leave;
infix:and(/hello/, { say Two })
continue unless /hello/; say Two;
/hello { say Two }/;
s/hello/{ say Two }$0/;
({}, { say Two })[?/hello/]();
and probably a few more I can't think of off the top of my head.
Larry
Re: When scoping
On May 4, 2005, at 23:19 , Larry Wall wrote:
You must have missed the implied ... at the end of my list of
other WTDI.
You can also do any of:
say Two if /hello/;
/hello/ say Two;
/hello/ and say Two;
/hello/ ?? say Two :: leave;
infix:and(/hello/, { say Two })
continue unless /hello/; say Two;
/hello { say Two }/;
s/hello/{ say Two }$0/;
({}, { say Two })[?/hello/]();
and probably a few more I can't think of off the top of my head.
Okay then, pay no attention to my piddling contribution of a single
example. :-)
Best,
David
smime.p7s
Description: S/MIME cryptographic signature
When scoping
What should the output of this be:
given hello {
when /hello/ {
say One;
when /hello/ { say Two; }
when /hello/ { say Three; }
continue;
}
say Four;
}
I think:
One
Two
Three
Four
But pugs thinks:
One
Two
The trouble is that I can't seem to come up with an example to test
whether the nested whens are breaking out of the outer when or the
given. Anyway, I'm more curious what Perl 6 thinks it should do.
Luke
Re: When scoping
On Wed, May 04, 2005 at 11:00:31PM -0600, Luke Palmer wrote:
: What should the output of this be:
:
: given hello {
: when /hello/ {
: say One;
: when /hello/ { say Two; }
: when /hello/ { say Three; }
: continue;
: }
: say Four;
: }
:
: I think:
:
: One
: Two
: Three
: Four
:
: But pugs thinks:
:
: One
: Two
I'm inclined to think Pugs has it right here.
: The trouble is that I can't seem to come up with an example to test
: whether the nested whens are breaking out of the outer when or the
: given. Anyway, I'm more curious what Perl 6 thinks it should do.
Perl 6 thinks :-) that break (either implicit or explicit) should
break out of the topicalizer block and ignore non-topicalizer
intermediate blocks, just as next and last ignore any non-loop
blocks to find the innermost enclosing loop, and return ignores
inner blocks to find the true sub block. (And the inner when
isn't considered a retopicalization.)
To get the other behavior, you have to say one of:
given hello {
when /hello/ {
say One;
when /hello/ { say Two; continue; }
when /hello/ { say Three; continue; }
continue;
}
say Four;
}
given hello {
when /hello/ {
say One;
say Two when /hello/;
say Three when /hello/;
continue;
}
say Four;
}
given hello {
when /hello/ {
say One;
if /hello/ { say Two; }
if /hello/ { say Three; }
continue;
}
say Four;
}
That seems like enough WTDI. (Though arguably, the continue version
could be defined to skip Three. But it seems more straightfoward
to define it as leaving the current when block.)
Larry
