NAME¶
Data::Miscellany - Collection of miscellaneous subroutines
VERSION¶
version 1.100850
SYNOPSIS¶
use Data::Miscellany qw/set_push flex_grep/;
my @foo = (1, 2, 3, 4);
set_push @foo, 3, 1, 5, 1, 6;
# @foo is now (1, 2, 3, 4, 5, 6);
flex_grep('foo', [ qw/foo bar baz/ ]); # true
flex_grep('foo', [ qw/bar baz flurble/ ]); # false
flex_grep('foo', 1..4, 'flurble', [ qw/foo bar baz/ ]); # true
flex_grep('foo', 1..4, [ [ 'foo' ] ], [ qw/bar baz/ ]); # false
DESCRIPTION¶
This is a collection of miscellaneous subroutines useful in wide but varying
scenarios; a catch-all module for things that don't obviously belong anywhere
else. Obviously what's useful differs from person to person, but this
particular collection should be useful in object-oriented frameworks, such as
Class::Scaffold and Data::Conveyor.
FUNCTIONS¶
set_push(ARRAY, LIST)¶
Like "push()", but only pushes the item(s) onto the list indicated by
the list or list ref (the first argument) if the list doesn't already contain
it.
Example:
@foo = (1, 2, 3, 4);
set_push @foo, 3, 1, 5, 1, 6;
# @foo is now (1, 2, 3, 4, 5, 6)
flatten()¶
If the first argument is an array reference, it returns the dereferenced array.
If the first argument is undefined (or there are no arguments), it returns the
empty list. Otherwise the argument list is returned as is.
flex_grep(SCALAR, LIST)¶
Like "grep()", but compares the first argument to each flattened (see
"flatten()") version of each element of the list.
Examples:
flex_grep('foo', [ qw/foo bar baz/ ]) # true
flex_grep('foo', [ qw/bar baz flurble/ ]) # false
flex_grep('foo', 1..4, 'flurble', [ qw/foo bar baz/ ]) # true
flex_grep('foo', 1..4, [ [ 'foo' ] ], [ qw/bar baz/ ]) # false
is_deeply()¶
Like Test::More's "is_deeply()" except that this version respects
stringification overloads. If a package overloads stringification, it means
that it specifies how it wants to be compared. Recent versions of Test::More
break this behaviour, so here is a working version of "is_deeply()".
This subroutine only does the comparison; there are no test diagnostics or
results recorded or printed anywhere.
eq_array()¶
Like Test::More's "eq_array()" except that this version respects
stringification overloads. If a package overloads stringification, it means
that it specifies how it wants to be compared. Recent versions of Test::More
break this behaviour, so here is a working version of "eq_array()".
This subroutine only does the comparison; there are no test diagnostics or
results recorded or printed anywhere.
eq_hash()¶
Like Test::More's "eq_hash()" except that this version respects
stringification overloads. If a package overloads stringification, it means
that it specifies how it wants to be compared. Recent versions of Test::More
break this behaviour, so here is a working version of "eq_hash()".
This subroutine only does the comparison; there are no test diagnostics or
results recorded or printed anywhere.
is_defined(SCALAR)¶
A kind of "defined()" that is aware of Class::Value, which has its own
views of what is a defined value and what isn't. The issue arose since
Class::Value objects are supposed to be used transparently, mixed with normal
scalar values. However, it is not possible to overload
"definedness", and "defined()" used on a value object
always returns true since the object reference certainly exists. However, what
we want 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.