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# 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.
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