Re: Unexpected expansion of string with xx
On 12/20/2013 04:52 AM, Richard Hainsworth wrote: OK x not xx. The doubling of operators is confusing. OTOH having a single operator which two different meanings is also confusing (and very un-perlish). Cheers, Moritz
Re: Unexpected expansion of string with xx
On Dec 21, 2013, at 12:00 AM, Moritz Lenz mor...@faui2k3.org wrote: On 12/20/2013 04:52 AM, Richard Hainsworth wrote: OK x not xx. The doubling of operators is confusing. OTOH having a single operator which two different meanings is also confusing (and very un-perlish). Sometimes, yeah. On a related note, I sometimes wish that qw«= » and the like were general-purpose comparison operators rather than explicitly numeric comparators. I understand why Perl uses them in the way that it does (mainly, it’s a legacy thing from Perl 5, when there weren’t any data types and the distinction between “number” and “string” had to be built into the operator); but it takes a lot of getting used to, and there are times that I wish that the language would use some argument-based magic to let me sort arbitrary objects using “” instead of “before”. If it wasn’t for the need for backward compatibility, I’d want something like the following: $a $b :as(Num) #[coerce $a and $b to Num. Same as “$a $b” now.] $a $b :as(Str) #[coerce $a and $b to Str. Same as “$a lt $b” now.] $a $b :as(*) #[don’t coerce anything. Same as “$a before $b” now.] $a $b #[coerce $b to whatever type $a is for the comparison. No simple equivalent now.] That strikes me as better “principle of least surprise” than the current approach. Alas, I suspect that the ship has long since sailed on this idea.
Re: Unexpected expansion of string with xx
My mnemonic is x (one thing) is for scalars, xx (many things) is for
lists. Using that, there's seldom any confusion.
The reason Perl 6 makes the distinction is that (unlike Perl 5) it
*has to*. Perl 5 does context-based dispatch, whereas Perl 6 does
argument-based dispatch. We greatly prefer the latter, and it's an
either-or situation, so two operators it is.
// Carl
On Fri, Dec 20, 2013 at 4:52 AM, Richard Hainsworth
rich...@rusrating.ru wrote:
OK x not xx.
The doubling of operators is confusing.
Richard
On 12/19/2013 10:01 PM, Jonathan Worthington wrote:
On 12/19/2013 3:47, Richard Hainsworth wrote:
Initially I though the following was a bug, but now I'm not sure.
I got these results
perl6 -v
This is perl6 version 2013.09 built on parrot 5.5.0 revision 0
$ perl6
say '0' xx 4
0 0 0 0
Are you sure you didn't want the x (string repetition) operator, instead
of xx (list repetition)?
print '0' xx 4
print 's' ~ ('0' xx 4)
s0 0 0 0
I'm not sure why the elements of the expansion are padded with a trailing
space in one context but not in another.
print calls .Str, say calls .gist.
I wasn't sure whether this is the specified behaviour.
It is.
If it is how can it be turned off?
Call .Str or .gist on the argument to print/say as needed.
I suspect that the problem will be resolved by using the x operator
instead of xx, however. :-)
/jnthn
Re: Unexpected expansion of string with xx
On 12/19/2013 3:47, Richard Hainsworth wrote:
Initially I though the following was a bug, but now I'm not sure.
I got these results
perl6 -v
This is perl6 version 2013.09 built on parrot 5.5.0 revision 0
$ perl6
say '0' xx 4
0 0 0 0
Are you sure you didn't want the x (string repetition) operator, instead
of xx (list repetition)?
print '0' xx 4
print 's' ~ ('0' xx 4)
s0 0 0 0
I'm not sure why the elements of the expansion are padded with a
trailing space in one context but not in another.
print calls .Str, say calls .gist.
I wasn't sure whether this is the specified behaviour.
It is.
If it is how can it be turned off?
Call .Str or .gist on the argument to print/say as needed.
I suspect that the problem will be resolved by using the x operator
instead of xx, however. :-)
/jnthn
Re: Unexpected expansion of string with xx
OK x not xx.
The doubling of operators is confusing.
Richard
On 12/19/2013 10:01 PM, Jonathan Worthington wrote:
On 12/19/2013 3:47, Richard Hainsworth wrote:
Initially I though the following was a bug, but now I'm not sure.
I got these results
perl6 -v
This is perl6 version 2013.09 built on parrot 5.5.0 revision 0
$ perl6
say '0' xx 4
0 0 0 0
Are you sure you didn't want the x (string repetition) operator,
instead of xx (list repetition)?
print '0' xx 4
print 's' ~ ('0' xx 4)
s0 0 0 0
I'm not sure why the elements of the expansion are padded with a
trailing space in one context but not in another.
print calls .Str, say calls .gist.
I wasn't sure whether this is the specified behaviour.
It is.
If it is how can it be turned off?
Call .Str or .gist on the argument to print/say as needed.
I suspect that the problem will be resolved by using the x operator
instead of xx, however. :-)
/jnthn
