Re: for $arrayref {...}

2005-09-02 Thread Juerd 
Luke Palmer skribis 2005-09-01 23:43 (+):
 I would probably say that scalars never automatically dereference. 
 It's lists and hashes that automatically dereference/enreference. 

arrays

 That is, everything is a scalar, really, but if you have an @ or a %
 on the front of your variable, that means that you flatten yourself
 into specific kinds of contexts.

sub foo (@bar) { ... }

foo $aref;

Here $aref is dereferenced because of the Array context. The scalar
can't do this by itself, of course.


Juerd
-- 
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Re: for $arrayref {...}

2005-09-02 Thread Luke Palmer 
On 9/2/05, Juerd [EMAIL PROTECTED] wrote:
 Luke Palmer skribis 2005-09-01 23:43 (+):
  I would probably say that scalars never automatically dereference.
  It's lists and hashes that automatically dereference/enreference.
 
 arrays

Yes, arrays, right.

  That is, everything is a scalar, really, but if you have an @ or a %
  on the front of your variable, that means that you flatten yourself
  into specific kinds of contexts.
 
 sub foo (@bar) { ... }
 
 foo $aref;
 
 Here $aref is dereferenced because of the Array context. The scalar
 can't do this by itself, of course.

No, my view is that $foo and @foo are really the same kind of thing. 
They're both references to lists (yes, lists).  So binding @bar :=
$aref is not doing anything special, it's just like binding two
scalars.  The only thing that makes @bar different from $aref is that
in list context, @bar flattens out the list it's holding whereas $aref
doesn't.

Luke

multisub.arity?

2005-09-02 Thread Ingo Blechschmidt 
Hi,

multi foo ($a) {...}
multi foo ($a, $b) {...}

say foo.arity;
# die? warn and return 0? warn and return undef? return 1|2?


--Ingo

-- 
Linux, the choice of a GNU | There are no answers, only
generation on a dual AMD   | cross-references.  
Athlon!|

Re: multisub.arity?

2005-09-02 Thread Larry Wall 
On Fri, Sep 02, 2005 at 05:56:39PM +0200, Ingo Blechschmidt wrote:
: Hi,
: 
: multi foo ($a) {...}
: multi foo ($a, $b) {...}
: 
: say foo.arity;
: # die? warn and return 0? warn and return undef? return 1|2?

How 'bout undef but 1..2?  :-)

Larry

undef but 1..2?

2005-09-02 Thread Ingo Blechschmidt 
Hi,

Larry Wall wrote:
 On Fri, Sep 02, 2005 at 05:56:39PM +0200, Ingo Blechschmidt wrote:
 : multi foo ($a) {...}
 : multi foo ($a, $b) {...}
 : 
 : say foo.arity;
 : # die? warn and return 0? warn and return undef? return 1|2?
 
 How 'bout undef but 1..2?  :-)

Interesting, but now you have to elaborate a bit. :)

I've thought there're two forms of the but operator:

my $foo = Foo.new but {
.bar($baz);
.grtz = baka;
};

$obj but SomeRole;
# leaves $obj untouched and returns $obj with the SomeRole role
# incorporated, i.e. .does(SomeRole) is true then
0 but true;   # is really
0 but bool::true  # works, as bool::true is a role
0 but 42; # error: Can't use 42 as a role

Ok. But what about undef but 1..2? 1..2 isn't a role, right? So how can
infix:but work with it?


--Ingo, who has probably misunderstood your :-) :)

-- 
Linux, the choice of a GNU | The future is here. It's just not widely
generation on a dual AMD   | distributed yet.  -- William Gibson  
Athlon!|

Re: for $arrayref {...}

2005-09-02 Thread Yuval Kogman 
On Fri, Sep 02, 2005 at 09:24:52 +0200, Juerd wrote:

 sub foo (@bar) { ... }
 
 foo $aref;
 
 Here $aref is dereferenced because of the Array context. The scalar
 can't do this by itself, of course.

my @bar := $aref;

-- 
 ()  Yuval Kogman [EMAIL PROTECTED] 0xEBD27418  perl hacker 
 /\  kung foo master: /me kicks %s on the nose: neeyah!



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