Re: Calling a hash member

If you really don't want to use a temporary variable (though I don't see why not), it may be possible to store a hard reference instead of a soft reference:

  use ProjectA;
  my $project = 'ProjectA';
  my %ThingsToDo = (firstTask => \{$project->prepare});
  $ThingsToDo{firstTask};
[download]

Alternatively, you could make a dispatcher method in the ProjectA class that executes a given method:

  use ProjectA;
  my $project = 'ProjectA';
  my %ThingsToDo = (firstTask => 'prepare');
  $project->doMethod($ThingsToDo{firstTask});
[download]

Comment on Re: Calling a hash member Select or Download Code

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Re^2: Calling a hash member by ikegami (Patriarch) on Dec 13, 2006 at 21:27 UTC
Your first snippet doesn't work. For example, the following doesn't print `1` and `2`. `{ package ProjectA; { my $i; sub prepare { print ++$i, "\n"; } } } my $project = 'ProjectA'; my %ThingsToDo = (firstTask => \{$project->prepare}); $ThingsToDo{firstTask}; $ThingsToDo{firstTask};` [download]	[reply] [d/l] [select]
Re^3: Calling a hash member by geekphilosopher (Friar) on Dec 14, 2006 at 01:46 UTC
Hrm, good catch. Do you happen to know why this doesn't work? Does the coderef not maintain the closure or something?	[reply]
Re^4: Calling a hash member by ikegami (Patriarch) on Dec 14, 2006 at 02:06 UTC
`my $r = \{expr};` [download] is the same thing as `my @rv = expr; my %h = @rv; my $hr = \%h; my $r = \$hr;` [download] There's no coderef anywhere in there. That sets the value at key `firstTask` to a reference to a reference to a hash which was initialized with the result of `prepare`. Furthermore, `$ThingsToDo{firstTask};` [download] is a no-op. Even if `$ThingsToDo{firstTask}` returned a code reference, there's nothing to cause the referenced code to get executed. To execute the code referenced by `$ThingsToDo{firstTask}`, use `&{$ThingsToDo{firstTask}}();` [download] or better yet, `$ThingsToDo{firstTask}->();` [download] Finally, `$project` needs to be variable. It needs to be an argument. I think you meant `my %ThingsToDo = ( firstTask => sub { my $pkg = shift; $pkg->prepare(@_) }, ); ... $ThingsToDo{firstTask}->($project);` [download] But that's much more complex than required, and would involve lots of redundancy (`sub { my $pkg = shift; $pkg->XXX(@_) }`.	[reply] [d/l] [select]
Re^5: Calling a hash member by geekphilosopher (Friar) on Dec 14, 2006 at 02:42 UTC
Re^6: Calling a hash member by ikegami (Patriarch) on Dec 14, 2006 at 03:58 UTC
Re^2: Calling a hash member by revdiablo (Prior) on Dec 13, 2006 at 22:01 UTC
That should probably have been: `use ProjectA; my $project = 'ProjectA'; my %ThingsToDo = (firstTask => sub { $project->prepare }); $ThingsToDo{firstTask}->();` [download]	[reply] [d/l]