http://www.perlmonks.org?node_id=996787


in reply to Invoking a method whose name is computed

Is there a more straightforward version?

I don't know if you will consider it more straightforward, but the  can() universal method can be used here (see The UNIVERSAL Class in perlobj). As the original example is a class method call, argument passing is, well, straightforward. Had it been an object method, the object reference would need to be passed explicitly as the first argument. (Update: See the reply of afoken for the correct way to invoke with class name or object reference.) Also be aware that if the method does not exist,  can() returns undef. 

>perl -wMstrict -le
"use 5.014;
 ;;
 package Foo {
   sub bar_baz { print 'i am bar_bazing! ', @_; }
   }
 ;;
 my $x = 'baz';
 Foo->can(qq{bar_$x})->('Hooray!');
"
i am bar_bazing! Hooray!

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Re^2: Invoking a method whose name is computed
by afoken (Chancellor) on Oct 02, 2012 at 05:43 UTC

    You invoke Foo::bar_baz as function, not as method. For a method call, the object / class name implicitly added by perl is missing, so you have to add it manually:

    Class->can("prefix_$name")->(Class,'first argument');
$object->can("prefix_$name")->($object,'first argument');

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    Hardly DRY. I prefer "wasting" a variable for composed method names:

    my $method="prefix_$name";
Class->$method('first argument');
$object->$method('first argument');

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    Alexander

    --
    Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
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      An advantage of the "wasted variable" (I prefer to think it is an "intelligently used variable") is that you can perform a little validation:

      my $object = bless {hi => 'hello'};

for my $suffix ('x', 'y') {
    my $method = $object->can("prefix_$suffix");
    $object->$method() if $method;
}


sub prefix_x {
    my ($self) = @_;
    
    print "$self->{hi} world\n";
}

      [download]

      Update: elaborate code to better show intent.

      True laziness is hard work
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Re^2: Invoking a method whose name is computed
by tobyink (Canon) on Oct 02, 2012 at 16:30 UTC

    A pretty good solution, but doesn't work for autoloaded methods unless the developer has been conscientious and overloaded can correctly.

    perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
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