Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

I used the recommended goto SUB way. Here’s what happens.

There are two programs, in both debug is a fancy little debug message printer. In one of them, _debug is an actual sub that does a little more than this, it also sends the debug message to a server for central logging. In the other app, _debug is just an alias, so any case of _debug will still work: *_debug = \&debug;

Now, in the app that has the actual sub _debug { ... } declared, Perl will tell me ‘Ambiguous use of &{_debug} resolved to &_debug’, for a line which contains the following: goto &{_debug};

What exactly might be so ambiguous about this?


Relevant code pieces for easier understanding:

package OO::SubModule; sub new { my ($class, $args) = @_; my $self = { ( defined $args ? %$args : () ) }; bless($self, $class); ## Some boilerplate debug callback that we can override during const +ruction $self->{debug_cb} //= sub { my $self = shift; carp("DEBUG ".join(", +", map { defined $_ ? $_ : "undef" } @_)); }; return $self; } sub _debug { my $self = $_[0]; goto &{$self->{debug_cb}}; } ## You can say $self->_debug("booya") to do $self->{debug_cb}->("booya +") without it ending up in the call stack
## both apps $oosub = OO::SubModule->new({ debug_cb => sub { my $self = shift; my ($str) = @_; goto &{_debug}; }, }); ## Any occurrence of $self->_debug("booya") within OO::SubModule reall +y does _debug("booya") of the main app, this way ## Without getting in the call stack, right?

In reply to Re: Can caller() or the call stack be tricked? by Ralesk
in thread Can caller() or the call stack be tricked? by Ralesk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others rifling through the Monastery: (4)
As of 2024-03-19 05:13 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found