NAME¶
Sub::Defer - defer generation of subroutines until they are first called
SYNOPSIS¶
use Sub::Defer;
my $deferred = defer_sub 'Logger::time_since_first_log' => sub {
my $t = time;
sub { time - $t };
};
Logger->time_since_first_log; # returns 0 and replaces itself
Logger->time_since_first_log; # returns time - $t
DESCRIPTION¶
These subroutines provide the user with a convenient way to defer creation of
subroutines and methods until they are first called.
SUBROUTINES¶
defer_sub¶
my $coderef = defer_sub $name => sub { ... };
This subroutine returns a coderef that encapsulates the provided sub - when it
is first called, the provided sub is called and is -itself- expected to return
a subroutine which will be goto'ed to on subsequent calls.
If a name is provided, this also installs the sub as that name - and when the
subroutine is undeferred will re-install the final version for speed.
undefer_sub¶
my $coderef = undefer_sub \&Foo::name;
If the passed coderef has been deferred this will "undefer" it. If the
passed coderef has not been deferred, this will just return it.
If this is confusing, take a look at the example in the "SYNOPSIS".
undefer_all¶
undefer_all();
This will undefer all defered subs in one go. This can be very useful in a
forking environment where child processes would each have to undefer the same
subs. By calling this just before you start forking children you can undefer
all currently deferred subs in the parent so that the children do not have to
do it.
SUPPORT¶
See Moo for support and contact information.
AUTHORS¶
See Moo for authors.
COPYRIGHT AND LICENSE¶
See Moo for the copyright and license.