oracular (3) Call::Context.3pm.gz

NAME

       Call::Context - Sanity-check calling context

SYNOPSIS

           use Call::Context;

           sub gives_a_list {

               # Will die() if the context is not list.
               Call::Context::must_be_list();

               return (1, 2, 3);
           }

           gives_a_list();             # die()s: incorrect context (void)

           my $v = gives_a_list();     # die()s: incorrect context (scalar)

           my @list = gives_a_list();  # lives

           #----------------------------------------------------------------------

           sub scalar_is_bad {

               # Will die() if the context is scalar.
               Call::Context::must_not_be_scalar();

               return (1, 2, 3);
           }

           scalar_is_bad();            # die()s: incorrect context (void)

           my $v = scalar_is_bad();    # die()s: incorrect context (scalar)

           my @list = scalar_is_bad(); # lives

DESCRIPTION

       If your function only expects to return a list, then a call in some other context is, by definition, an
       error. The problem is that, depending on how the function is written, it may actually do something
       expected in testing, but then in production act differently.

FUNCTIONS

   must_be_list()
       die()s if the calling function is itself called outside list context.  (See the SYNOPSIS for examples.)

   must_not_be_scalar()
       die()s if the calling function is itself called in scalar context.  (See the SYNOPSIS for examples.)

EXCEPTIONS

       This module throws instances of "Call::Context::X". "Call::Context::X" is overloaded to stringify;
       however, to keep memory usage low, "overload" is not loaded until instantiation.

REPOSITORY

       https://github.com/FGasper/p5-Call-Context

LICENSE

       This module is licensed under the MIT License.