split on empty string

"".split(':') =>

() # Perl 5
("",) # pugs

Which is correct? It doesn's seem to be specced yet.

--
Gaal Yahas <ga...@forum2.org>
http://gaal.livejournal.com/

I would prefer the current pugs behavior; it's consistent with the general
case, in which a string which does not match the splitting regex results in
a single-item list containing the original string. This is the Python
behavior.

I find the Perl5 (and, surprisingly, Ruby) behavior rather counterintuitive.

FWIW, I agree with Mark.

-Scott
--
Jonathan Scott Duff
du...@pobox.com

>>> [split on empty string] doesn's seem to be specced yet.

Just to show opposite, I've always found that behavior (i.e.
returning the original string unchanged) confusing. C<split> works
based on sequential examination of the target string to locate
matching substrings on which to split. There is a matching "empty
string" substring between every character. Naturally, what you get
back is an array of characters.

Plus, it's a useful idiom.

--Dks

You misunderstand. We're not talking about splitting a string with the
empty string as the delimiter. We're talking about splitting the empty
string (as the target), with any delimiter whatsoever. If you do that, what
you get back is an empty array.

Perl6 "".split(/whatever/) is equivalent to split(/whatever/,"") in Perl5.
It's not like the silly Python idiom where the invocant is the delimiter
string. :)

So this is the Perl5 to which I was referring:

my @result = split(/whatever/, "");
print ~~@result,"\n"; # --> 0

The general case I was comparing it to is when the target string is *not*
empty but doesn't match, in which case you get the original string back:

my @result = split(/foo/, "bar");
print ~~@result,"\n"; # --> 1
print $result[0],"\n"; # --> "bar"

I'm hoping that the perl 5 syntax will still be valid in perl 6.

--
Jonathan "Dataweaver" Lang

This has nothing to do with splitting on the empty string, per se, but
with Perl 5 stripping trailing null fields by default:

@results = split(/:/,'::::');
print @results + 0; # prints '0'

I think we could make that behavior optional now with :trim or some
such. The original motivation has largely gone away with the advent
of autochomping filehandles, so split /\s+/ won't produce a spurious
null field after the \n.

Larry

Don't worry, it is.

Juerd
--
http://convolution.nl/maak_juerd_blij.html
http://convolution.nl/make_juerd_happy.html
http://convolution.nl/gajigu_juerd_n.html

Yep, it's mostly just the semantics we're screwing around with. :-)

Larry