NAME Sub::Operable - apply Perl built-in operators to coderefs SYNOPSIS use Sub::Operable 'subop'; # f(x) = x² # my $f = subop { $_ ** 2 }; # f(4) = 4² # = 16 # say $f->(4); # ==> 16 # g(x) = 2x # my $g = subop { 2 * $_ }; # h = f + g + 3 # my $h = $f + $g + 3; # h(10) = f(10) + g(10) + 3 # = 10² + 2(10) + 3 # = 100 + 20 + 3 # = 123 # say $h->(10); # ==> 123 DESCRIPTION Sub::Operator allows you to define functions and apply operations to the functions like you can in algebra class. All the standard built-in binary, string, numeric, and comparison operators should work fine. Operators like `+=` which mutate their operands are not supported. Additionally if you call a Sub::Operator-enabled function passing another Sub::Operator-enabled function as an argument, you get a composed Sub::Operator-enabled function as the result. # Assume $f and $g defined as above. # m(x) = g( f(x) ) # my $m = $g->( $f ); # m(10) = g( f(10) ) # = g( 10² ) # = g( 100 ) # = 2 * 100 # = 200 # say $m->(10); # ==> 200 Object-Oriented Constructor use Sub::Operable; my $coderef = 'Sub::Operable'->new(sub { ... }); When the coderefs are called, $_ will be an alias of $_[0]. Shortcut Constructor use Sub::Operable qw( subop ); my $coderef = subop { ... }; When the coderefs are called, $_ will be an alias of $_[0]. Utility Function use Sub::Operable qw( isa_Sub_Operable ); my $bool = isa_Sub_Operable( $coderef ); Constants You can get lists of supported operators: use Sub::Operable; my @prefix = Sub::Operable::PREFIX_OPS; my @infix = Sub::Operable::INFIX_OPS; Symbol Table Frickery You don't have to just deal with coderefs. You can put these functions into the symbol table. use Sub::Operable 'subop'; # f(x) = x² # *f = subop { $_ ** 2 }; # f(4) = 4² # = 16 # say f(4); # ==> 16 # g(x) = 2x # *g = subop { 2 * $_ }; # h = f + g + 3 # *h = \&f + \&g + 3; # h(10) = f(10) + g(10) + 3 # = 10² + 2(10) + 3 # = 100 + 20 + 3 # = 123 # say h(10); # ==> 123 BUGS Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=Sub-Operable>. SEE ALSO curry, I guess? AUTHOR Toby Inkster <tobyink@cpan.org>. COPYRIGHT AND LICENCE This software is copyright (c) 2020 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. DISCLAIMER OF WARRANTIES 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.