/ 
Data-Object-0.28
River stage one • 1 direct dependent • 1 total dependent
/ Data::Object::Code

NAME

Data::Object::Code - A Code Object for Perl 5

VERSION

version 0.28

SYNOPSIS

use Data::Object::Code;

my $code = Data::Object::Code->new(sub { shift + 1 });

DESCRIPTION

Data::Object::Code provides common methods for operating on Perl 5 code references. Code methods work on code references.

COMPOSITION

This class inherits all functionality from the Data::Object::Role::Code role and implements proxy methods as documented herewith.

CODIFICATION

Certain methods provided by the this module support codification, a process which converts a string argument into a code reference which can be used to supply a callback to the method called. A codified string can access its arguments by using variable names which correspond to letters in the alphabet which represent the position in the argument list. For example:

$array->example('$a + $b * $c', 100);

# if the example method does not supply any arguments automatically then
# the variable $a would be assigned the user-supplied value of 100,
# however, if the example method supplies two arguments automatically then
# those arugments would be assigned to the variables $a and $b whereas $c
# would be assigned the user-supplied value of 100

Any place a codified string is accepted, a coderef or Data::Object::Code object is also valid. Arguments are passed through the usual @_ list.

METHODS

call

# given sub { (shift // 0) + 1 }

$code->call; # 1
$code->call(0); # 1
$code->call(1); # 2
$code->call(2); # 3

The call method executes and returns the result of the code. This method returns a data type object to be determined after execution.

compose

# given sub { [@_] }

$code = $code->compose($code, 1,2,3);
$code->(4,5,6); # [[1,2,3,4,5,6]]

# this can be confusing, here's what's really happening:
my $listing = sub {[@_]}; # produces an arrayref of args
$listing->($listing->(@args)); # produces a listing within a listing
[[@args]] # the result

The compose method creates a code reference which executes the first argument (another code reference) using the result from executing the code as it's argument, and returns a code reference which executes the created code reference passing it the remaining arguments when executed. This method returns a Data::Object::Code object.

conjoin

# given sub { $_[0] % 2 }

$code = $code->conjoin(sub { 1 });
$code->(0); # 0
$code->(1); # 1
$code->(2); # 0
$code->(3); # 1
$code->(4); # 0

The conjoin method creates a code reference which execute the code and the argument in a logical AND operation having the code as the lvalue and the argument as the rvalue. This method returns a Data::Object::Code object.

curry

# given sub { [@_] }

$code = $code->curry(1,2,3);
$code->(4,5,6); # [1,2,3,4,5,6]

The curry method returns a code reference which executes the code passing it the arguments and any additional parameters when executed. This method returns a Data::Object::Code object.

disjoin

# given sub { $_[0] % 2 }

$code = $code->disjoin(sub { -1 });
$code->(0); # -1
$code->(1); #  1
$code->(2); # -1
$code->(3); #  1
$code->(4); # -1

The disjoin method creates a code reference which execute the code and the argument in a logical OR operation having the code as the lvalue and the argument as the rvalue. This method returns a Data::Object::Code object.

next

$code->next;

The next method is an alias to the call method. The naming is especially useful (i.e. helps with readability) when used with closure-based iterators. This method returns a Data::Object::Code object. This method is an alias to the call method.

rcurry

# given sub { [@_] }

$code = $code->rcurry(1,2,3);
$code->(4,5,6); # [4,5,6,1,2,3]

The rcurry method returns a code reference which executes the code passing it the any additional parameters and any arguments when executed. This method returns a Data::Object::Code object.

SEE ALSO

AUTHOR

Al Newkirk <anewkirk@ana.io>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Al Newkirk.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.