Data-Miscellany
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to know is whether the value encapsulated by the value object is
defined. Additionally, each value class can have its own ideas of when
its encapsulated value is defined. Therefore, Class::Value has an
"is_defined()" method.
This subroutine checks whether its argument is a value object and if so,
calls the value object's "is_defined()" method. Otherwise, the normal
"defined()" is used.
value_of(SCALAR)
Stringifies its argument, but returns undefined values (per
"is_defined()") as "undef".
str_value_of(SCALAR)
Stringifies its argument, but returns undefined values (per
"is_defined()") as the empty string.
class_map(SCALAR, HASH)
Takes an object or class name as the first argument (if it's an object,
the class name used will be the package name the object is blessed
into). Takes a hash whose keys are class names as the second argument.
The hash values are completely arbitrary.
Looks up the given class name in the hash and returns the corresponding
value. If no such hash key is found, the class hierarchy for the given
class name is traversed depth-first and checked against the hash keys in
turn. The first value found is returned.
If no key is found, a special key, "UNIVERSAL" is used.
As an example of how this might be used, consider a hierarchy of
exception classes. When evaluating each exception, we want to know how
severe this exception is, so we define constants for "RC_OK" (meaning
it's informational only), "RC_ERROR" (meaning some sort of action should
be taken) and "RC_INTERNAL_ERROR" (meaning something has gone badly
wrong and we might halt processing). In the following table assume that
if you have names like "Foo::Bar" and "Foo::Bar::Baz", then the latter
subclasses the former.
%map = (
'UNIVERSAL' => RC_INTERNAL_ERROR,
'My::Exception::Business' => RC_ERROR,
'My::Exception::Internal' => RC_INTERNAL_ERROR,
'My::Exception::Business::ValueNormalized' => RC_OK,
);
Assuming that "My::Exception::Business::IllegalValue" exists and that it
subclasses "My::Exception::Business", here are some outcomes:
class_map('My::Exception::Business::IllegalValue', \%map) # RC_ERROR
class_map('My::Exception::Business::ValueNormalzed', \%map) # RC_OK
trim(STRING)
Trims off whitespace at the beginning and end of the string and returns
the trimmed string.
INSTALLATION
See perlmodinstall for information and options on installing Perl
modules.
BUGS AND LIMITATIONS
No bugs have been reported.
Please report any bugs or feature requests through the web interface at
<http://rt.cpan.org/Public/Dist/Display.html?Name=Data-Miscellany>.
AVAILABILITY
The latest version of this module is available from the Comprehensive
Perl Archive Network (CPAN). Visit <http://www.perl.com/CPAN/> to find a
CPAN site near you, or see
<http://search.cpan.org/dist/Data-Miscellany/>.
The development version lives at
<http://github.com/hanekomu/Data-Miscellany/>. Instead of sending
patches, please fork this project using the standard git and github
infrastructure.
AUTHOR
Marcel Gruenauer <marcel@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2004 by Marcel Gruenauer.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
( run in 1.584 second using v1.01-cache-2.11-cpan-39bf76dae61 )