| match::simple::sugar(3pm) | User Contributed Perl Documentation | match::simple::sugar(3pm) |
match::simple::sugar - a few extras for match::simple
This module provides a "given"/"when" substitute for match::simple.
use match::simple::sugar;
for ( $var ) {
when 'foo', then { ... };
when 'bar', 'baz', then { ... };
...; # otherwise
}
It also provides a function for numeric matching (because match::simple always assumes you want stringy matching if the right-hand-side is a defined non-reference value).
use match::simple::sugar;
for ( $var ) {
when numeric 0, then { ... };
when numeric 1, then { ... };
...; # otherwise
}
This module exports three functions "when", "then", and "numeric", and also re-exports "match" from match::simple.
The "when" and "then" functions are intended to be used together, inside a "for ( SCALAR ) { ... }" block. The block acts as a topicalizer (it sets $_) and also a control-flow mechanism ("when" can use "next" to jump out of it). Any other use of "when" and "then" is unsupported.
"when( @values, $then )"
The "when" function accepts a list of values, followed by a special $then argument.
If $_ matches (according to the definition in match::simple) any of the values, then the $then argument will be executed, and "when" will use the Perl built-in "next" keyword to jump out of the surrounding "for" block.
"then { ... }"
The "then" function takes a block of code and returns an object suitable for use as "when"'s $then argument.
In the current implementation, the block of code should not inspect @_ or "wantarray", and should not use the "return", "next", "last", or "redo" keywords. (If you set any of the "PERL_STRICT", "EXTENDED_TESTING", "AUTHOR_TESTING", or "RELEASE_TESTING" environment variables to true, then match::simple::sugar will try to enforce this! This is intended to catch faulty "then" blocks when running your test suite.)
The "numeric" function accepts a number and returns a blessed object which has a "MATCH" method. The "MATCH" method returns true if it is called with a single defined non-referece scalar that is numerically equal to the original number passed to "numeric". Example:
numeric( '5.0' )->MATCH( '5.000' ); # true
This is intended for use in cases like:
if ( match $var, numeric 1 ) {
...;
}
Please report any bugs to <https://github.com/tobyink/p5-match-simple/issues>.
match::simple.
This module uses Exporter::Tiny.
Toby Inkster <tobyink@cpan.org>.
This module is inspired by a talk I gave to Boston.PM <https://boston-pm.github.io/>.
This software is copyright (c) 2023 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
| 2024-07-24 | perl v5.38.2 |