On 10/3/06, Aaron Sherman [EMAIL PROTECTED] wrote:
Paul Seamons wrote:
It relates to some old problems in the early part of the RFC/Apocalypse
process, and the fact that:
say $_ for 1..10 for 1..10
Was ambiguous. The bottom line was that you needed to define your
parameter name for
Damian Conway skribis 2006-10-03 16:40 (-0700):
Which can also be written as:
do { do { say 1 if 1 } if 1 } if 1;
Sorry, no it can't. From S4
(http://dev.perl.org/perl6/doc/design/syn/S04.html#The_repeat_statement):
Unlike in Perl 5, applying a statement modifier to a do block is
On 10/4/06, Juerd [EMAIL PROTECTED] wrote:
Damian Conway skribis 2006-10-03 16:40 (-0700):
Which can also be written as:
do { do { say 1 if 1 } if 1 } if 1;
Sorry, no it can't. From S4
(http://dev.perl.org/perl6/doc/design/syn/S04.html#The_repeat_statement):
Unlike in Perl 5,
It may be more useful to discuss this issue using less contrived
examples. :)
I would agree. I haven't had any use for a double if or a double for.
The double if case is handled by . The double for case is handled
by for and map.
The interesting cases are combinations of if and for and
:
perhaps a sentence to that effect belongs in S04, which has no mention
of nested statement modifiers, for or against.
Well, that's because Synopses at least in theory only refer to changes
from Perl 5. Perl 5 doesn't allow more than one statement modifier, and
Perl 6 doesn't either.
In Perl 5
Of course, that wasn't exactly what you were asking, but it does present
a practical solution when you want to:
{say $_ for =}.() if $do_read_input;
Which I just verified works fine under current pugs.
Thank you.
Hadn't thought of that. I think that is workable.
But it also brings
Paul Seamons wrote:
Of course, that wasn't exactly what you were asking, but it does present
a practical solution when you want to:
{say $_ for =}.() if $do_read_input;
Which I just verified works fine under current pugs.
Thank you.
Hadn't thought of that. I think that is workable.
- but will it be under Perl6.
Either way the nested statement modifiers would work even if scopes aren't
introduced at each level.
.say for 1..$_ for 2..5;
I think it reads sort of nicely left to right.
Paul
Paul Seamons wrote:
It relates to some old problems in the early part of the RFC/Apocalypse
process, and the fact that:
say $_ for 1..10 for 1..10
Was ambiguous. The bottom line was that you needed to define your
parameter name for that to work, and defining a parameter name on a
Aaron Sherman skribis 2006-10-03 13:46 (-0400):
In Perl 6, that's simplified to:
{{say 1 if 1}.() if 1}.() if 1;
Which can also be written as:
do { do { say 1 if 1 } if 1 } if 1;
Which if crammed together the way you wrote it, turns into:
do {do {say 1 if 1} if 1} if 1;
Or perhaps
[Apologies for the last post. Gmail got a little eager.
Here's what I meant to send...]
Juerd wrote:
Which can also be written as:
do { do { say 1 if 1 } if 1 } if 1;
Sorry, no it can't. From S4
(http://dev.perl.org/perl6/doc/design/syn/S04.html#The_repeat_statement):
Unlike in
在 Oct 4, 2006 7:46 AM 時，Damian Conway 寫到：
[Apologies for the last post. Gmail got a little eager.
Here's what I meant to send...]
Juerd wrote:
Which can also be written as:
do { do { say 1 if 1 } if 1 } if 1;
Sorry, no it can't. From S4
(http://dev.perl.org/perl6/doc/design/syn/
Audrey asked:
However, I wonder if this is too strict. Disallowing while and
until after a do block is fine (and can be coded directly in those
two statement modifier macros), but is there a reason to disallow
other modifiers?
Well, for a start, there's this syntactic problem:
do { say
在 Oct 4, 2006 10:17 AM 時，Damian Conway 寫到：
Audrey asked:
However, I wonder if this is too strict. Disallowing while and
until after a do block is fine (and can be coded directly in those
two statement modifier macros), but is there a reason to disallow
other modifiers?
Well, for a start,
The use case here is
do { .foo for @bar } if $baz;
But I guess you can always protect it with a parens:
(do { .foo for @bar }) if $baz;
Or just:
if $baz { .foo for @bar }
or even:
@bar».foo if $baz;
;-)
Damian
Paul == Paul Seamons [EMAIL PROTECTED] writes:
Paul I don't know what the reasoning was back then and it may be the same
today.
From my early conversations with Larry, I recall that the reason is that
RSTS/E BASIC-PLUS had nested trailing modifiers, and both Larry and I saw many
abuses of
Paul Seamons schreef:
In the samples you gave I had to read the entire line to see
what the outcome of the code is.
I was not addressing reading skills, but just your you'd either have
... or One always needs to read the full line, but one doesn't
have to do that linearly or just from
From my early conversations with Larry, I recall that the reason is that
RSTS/E BASIC-PLUS had nested trailing modifiers, and both Larry and I saw
many abuses of these over the years. Therefore, he decided not to repeat
that abomination, limiting it to precisely one level deep. I'm happy for
I will abuse it.
Paul
PS. And not that it matters, but TT3 is planned to support nested statement
modifiers and my engine which does much of TT3 already supports them - and I
do use them on occasion - but that's a different mailing list.
I'm not sure if I have seen this requested or discussed.
Is there a parsing reason why Perl 6 would allow nested statement modifiers or
is it mainly a sanity-please-don't-hurt-my-eyes reason.
It is silly to do things such as:
say Interesting if $just_because if $because;
But it is sort
In a message dated Fri, 1 Sep 2006, Paul Seamons writes:
I'm not sure if I have seen this requested or discussed.
This was definitively rejected by Larry in 2002:
http://www.nntp.perl.org/group/perl.perl6.language/9343
He has not revisited the issue in the several times it has come up
the issue in the several times it has come up since.
perhaps a sentence to that effect belongs in S04, which has no mention
of nested statement modifiers, for or against.
~jerry
/group/perl.perl6.language/9343
He has not revisited the issue in the several times it has come up since.
perhaps a sentence to that effect belongs in S04, which has no mention
of nested statement modifiers, for or against.
Well, that's because Synopses at least in theory only refer to changes
) of the Perl 6 grammar have changed and reverted and
changed again.
I don't know what the reasoning was back then and it may be the same today.
I'm just wondering what that reason is. Maybe nested statement modifiers
promote bad language skills. Maybe its because statement modifiers have
always
Paul Seamons schreef:
The following is one more interesting case.
say Ok then if $yes and $true unless $no or $false;
Without nested modifiers you'd have either:
say Ok then if $yes and $true and ! $no and ! $false;
or
say OK then unless ! $yes or ! $true or $no $or $false;
And
$no or $false or $yes and $true and say OK then ;
$no or $false or say OK then if $yes and $true ;
Thank you for your reply.
I know there are other ways to do it. I've had no choice but to do it other
ways in Perl5.
I don't think I have ever used that notation (outside of file open and
26 matches
Mail list logo
