nehlwyn has asked for the wisdom of the Perl Monks concerning the following question:

Greetings fellow monks ,

i have this simple question :

let's say i have a call to a subroutine , but i don't know how many arguments will be sent . Then inside the subroutine , there is a call to another function that needs a certain syntax , like an object method , so that i need some of the arguments to be wrtitten indivdually .

How do i do this ? 

# bad example 
...

way (@args);
#and let's say that in the course of the programm
#@args is made to equal ($a,$b,$c) 

...

sub way {
my ($aa,@bb)=@_; 
#because i don't know how many scalar are following $a/$aa
print "$aa is the first argument\n";
$aa->MethodCall(@_);
#but here i'd like to have the elements of @bb , but sorted 
#individually to have what would be, in this example, the equivalent
#of :
#$aa->MethodCall($main::a,$main::c);

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Is this clear ;-) ??? It shouldn't be , but as well it shouldn't baffle your wisdom ... so ...

The little one.

Replies are listed 'Best First'.
Re: i don't know rather take a look below
by japhy (Canon) on Aug 10, 2001 at 18:51 UTC
    You don't have the problem you think you do. 
    sub foo {
  my $obj = shift;
  $obj->method(@_);
}

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    works just fine. No problems. Or you're just not being specific enough.

    _____________________________________________________
    Jeff[japhy]Pinyan: Perl, regex, and perl hacker.
    s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

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Re: i don't know rather take a look below
by stefan k (Curate) on Aug 10, 2001 at 18:50 UTC
    Hi,
    maybe I don't get the point, but you say: 
    $aa->MethodCall(@_);
#but here i'd like to have the elements of @bb , but sorted

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    ... well, just do it: $aa->MethodCall(sort(@bb)); or am I missing something?

    BTW: it's easy to get really confused with @'s when you're coding in Ruby just on the other desktop *g*

    Regards... Stefan

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Use a hashref for named parameters...
by dragonchild (Archbishop) on Aug 10, 2001 at 19:01 UTC
    Give us a concrete example. My first reaction is that you're having problems with the naming of parameters. So, what I would do is pass your parameters in as a hashref. Something like: 
    sub first_sub {
    my ($args) = @_;

    # ... Do stuff here with $args->{FOO} ...

    $object->method(@{$args}{qw(ARG1 ARG2 ARG3)});

    # ... Do more stuff here, this time with $args->{ETC} ...
}

first_sub(
   {
    ARG1 => 0,
    ARG2 => 1,
    ARG3 => 2,
    FOO => 'bar',
    ETC => 'etc',
   },
);

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    That way, you're using Perl to name your arguments for you. The @{$args}{qw(ARG1 ARG2 ARG3)} syntax is a hashslice of a hashref. 
    my @temp = @{$args}{qw(ARG1 ARG2 ARG3)};

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    is equivalent to 
    my @temp;
push @temp, $args->{ARG1};
push @temp, $args->{ARG2};
push @temp, $args->{ARG3};

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    ------
    /me wants to be the brightest bulb in the chandelier!

    Vote paco for President!

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Re: i don't know rather take a look below
by Hofmator (Curate) on Aug 10, 2001 at 19:02 UTC

    Not sure if I'm getting you correctly ... I think you should write your subroutine like this 

    sub way {
  my $aa = shift;
  $aa->MethodCall(@_);
}

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    The shift takes the first argument out of @_ and puts it into $aa, the rest of the arguments are passed to MethodCall (and they are still an alias to the original variables, not a copy like in the call $aa->MethodCall(@bb)). I suppose there's a typo in your code 
    #$aa->MethodCall($main::a,$main::c);
# should be
#$aa->MethodCall($main::b,$main::c);
#                      ^^^

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    As a side remark, don't use the variables $a and $b as normal variables in a program, they are special to perl (see sort).

    -- Hofmator

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Re: i don't know rather take a look below
by bikeNomad (Priest) on Aug 10, 2001 at 18:52 UTC
    In your example, $aa would get the value of $a, and @bb would get ($b, $c). I don't know what you mean by "elements of @bb, but sorted individually", because $a isn't a member of @bb.

    Could you describe what you're trying to do a little better?

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      Sure ...

let's take an example where $abutton is a gtk button ,
$a its label , $bbutton if it exists a button from the
same button group .

...

#depending on the circumstances @args is either equal to
#($a) or ($a,$bbutton)
Make_Button($abutton,@args);

...

sub Make_Button {
my ($aa,@bb)=@_;
$aa = new Gtk::RadioButton(here must come either
                            $a
                            or $a,$bbutton);
}

#end of script

The syntax is very rigid , how do i manage to have the 
equivalent of  
$button = new Gtk::RadioButton($a, $bbutton);
within the sub , and starting from @bb

Sorry for the confusion , maybe it's confusing because i see
a problem where there's none ( but a mere
$aa = new Gtk::RadioButton(@bb) within the sub doesn't work 
so ...


P.S.: i pretty new , can you tell me where this message is
visible ? i have to pass through my home node to see it ...

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Re: i don't know rather take a look below
by nehlwyn (Acolyte) on Aug 10, 2001 at 20:12 UTC
    <HTML> <BODY>

    Greetings again and many thanks , fellow monks, i've taken a little of all your answers and along with a little cleaning of my code (;-) , it works fine now ... The Little One.

    </HTML> </BODY>
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