Checkfunctions
Check functions are introduced by the ":check" import tag, which check the argument type and return a
bool.
These functions also check for overloading magic, e.g. "${}" corresponds to a SCALAR reference.
is_scalar_ref(value)
Checks for a SCALAR reference.
is_array_ref(value)
Checks for an ARRAY reference.
is_hash_ref(value)
Checks for a HASH reference.
is_code_ref(value)
Checks for a CODE reference.
is_glob_ref(value)
Checks for a GLOB reference.
is_rx(value)
Checks for a regular expression reference generated by the "qr//" operator.
is_instance(value, class)
Checks for an instance of class.
It is equivalent to the following statement: "Scalar::Util::blessed($value) && $value->isa($class)".
is_invocant(value)
Checks for an invocant, i.e. a blessed reference or existent package name.
If value is a valid class name but does not exist, it will return false.
is_value(value)
Checks whether value is a primitive value, i.e. a defined, non-ref, and non-type-glob value.
This function has no counterpart for validation.
is_string(value)
Checks whether value is a string with non-zero-length contents, equivalent to "is_value($value) &&
length($value) > 0".
This function has no counterpart for validation.
is_number(value)
Checks whether value is a number. Here, a number means that the perl parser can understand it and
that the perl numeric converter (e.g. invoked by "sprintf '%g', $value") doesn't complain about it.
It is similar to Scalar::Util::looks_like_number() but refuses "infinity", "not a number" and "0 but
true". Note that "9**9**9" makes "infinity" and "9**9**9 - 9**9**9" makes "not a number".
This function has no counterpart for validation.
is_integer(value)
Checks whether value is an integer. An integer is also a number, so this function refuses "infinity"
and "not a number". See also is_number().
This function has no counterpart for validation.
Validatingfunctions
Validating functions are introduced by the ":validate" tag which checks for the argument and returns the
first argument. These are like the ":check" functions but dies if the argument type is invalid.
These functions also checks overloading magic, e.g. "${}" for a SCALAR reference.
scalar_ref(value)
Validates a SCALAR reference.
array_ref(value)
Validates an ARRAY reference.
hash_ref(value)
Validates a HASH reference.
code_ref(value)
Validates a CODE reference.
glob_ref(value)
Validates a GLOB reference.
rx(value)
Validates a regular expression reference.
instance(value, class)
Validates an instance of class.
invocant(value)
Validates an invocant, i.e. a blessed reference or existent package name.
If value is a valid class name and the class exists, then it returns the canonical class name, which
is logically cleaned up. That is, it runs "$value =~ s/^::(?:main::)*//;" before returning it.
NOTE: Canonization is done so due to an inconsistency between Perl versions. For instance:
package ::Foo; # OK
my $x = bless {}, '::Foo'; # OK
ref($x)->isa('Foo'); # Fatal
The last code snippet causes a fatal error: "Can't call method "isa" without package or object
reference". However, "invocant(ref $x)->isa('Foo')" is always OK.
Miscellaneousutilities
There are some other utility functions you can import from this module.
anon_scalar()
Generates an anonymous scalar reference to "undef".
anon_scalar(value)
Generates an anonymous scalar reference to the copy of value.
It is equivalent to "do{ my $tmp = $value; \$tmp; }".
neat(value)
Returns a neat string that is suitable to display.
This is a smart version of "<do{ defined($value) ? qq{"$value"} : 'undef' }">.
get_stash(invocant)
Returns the symbol table hash (also known as stash) of invocant if the stash exists.
install_subroutine(package, name => subr [, ...])
Installs subr into package as name.
It is similar to "do{ no strict 'refs'; *{$package.'::'.$name} = \&subr; }". In addition, if subr is
an anonymous subroutine, it is located into package as a named subroutine &package::name.
For example:
install_subroutine($pkg, say => sub{ print @_, "\n" });
install_subroutine($pkg,
one => \&_one,
two => \&_two,
);
# accepts a HASH reference
install_subroutine($pkg, { say => sub{ print @_, "\n" }); #
To re-install subr, use "no warnings 'redefine'" directive:
no warnings 'redefine';
install_subroutine($package, $name => $subr);
uninstall_subroutine(package, names...)
Uninstalls names from package.
It is similar to Sub::Delete::delete_sub(), but uninstall multiple subroutines at a time.
If you want to specify deleted subroutines, you can supply "name => \&subr" pairs.
For example:
uninstall_subroutine('Foo', 'hello');
uninstall_subroutine('Foo', hello => \&Bar::hello);
uninstall_subroutine($pkg,
one => \&_one,
two => \&_two,
);
# accepts a HASH reference
uninstall_subroutine(\$pkg, { hello => \&Bar::hello });
get_code_info(subr)
Returns a pair of elements, the package name and the subroutine name of subr.
It is similar to Sub::Identify::get_code_info(), but it returns the fully qualified name in scalar
context.
get_code_ref(package, name, flag?)
Returns &package::name if it exists, not touching the symbol in the stash.
if flag is a string "-create", it returns &package::name regardless of its existence. That is, it is
equivalent to "do{ no strict 'refs'; \&{package . '::' . $name} }".
For example:
$code = get_code_ref($pkg, $name); # like *{$pkg.'::'.$name}{CODE}
$code = get_code_ref($pkg, $name, -create); # like \&{$pkg.'::'.$name}
curry(subr, args and/or placeholders)
Makes subr curried and returns the curried subroutine.
This is also considered as lightweight closures.
See also Data::Util::Curry.
modify_subroutine(subr, ...)
Modifies subr with subroutine modifiers and returns the modified subroutine. This is also considered
as lightweight closures.
subr must be a code reference or callable object.
Optional arguments: "before => [subroutine(s)]" called before subr. "around => [subroutine(s)]"
called around subr. "after => [subroutine(s)]" called after subr.
This seems a constructor of modified subroutines and subroutine_modifier() is property accessors, but
it does not bless the modified subroutines.
subroutine_modifier(subr)
Returns whether subr is a modified subroutine.
subroutine_modifier(modified_subr, property)
Gets property from modified.
Valid properties are: "before", "around", "after".
subroutine_modifier(modified_subr, modifier => [subroutine(s)])
Adds subroutine modifier to modified_subr.
Valid modifiers are: "before", "around", "after".
mkopt(input, moniker, require_unique, must_be)
Produces an array of an array reference from input.
It is compatible with Data::OptList::mkopt(). In addition to it, must_be can be a HASH reference with
"name => type" pairs.
For example:
my $optlist = mkopt(['foo', bar => [42]], $moniker, $uniq, { bar => 'ARRAY' });
# $optlist == [[foo => undef], [bar => [42]]
mkopt_hash(input, moniker, must_be)
Produces a hash reference from input.
It is compatible with Data::OptList::mkopt_hash(). In addition to it, must_be can be a HASH reference
with "name => type" pairs.
For example:
my $optlist = mkopt(['foo', bar => [42]], $moniker, { bar => 'ARRAY' });
# $optlist == {foo => undef, bar => [42]}
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