File Coverage

blib/lib/Venus/Role/Catchable.pm

Criterion	Covered	Total	%
statement	21	22	95.4
branch	10	12	83.3
condition			n/a
subroutine	8	8	100.0
pod	2	4	50.0
total	41	46	89.1

package Venus::Role::Catchable;

use 5.018;

use strict;
use warnings;

use Venus::Role 'fault';

# AUDITS

sub AUDIT {
  my ($self, $from) = @_;

  if (!$from->does('Venus::Role::Tryable')) {
    fault "${self} requires ${from} to consume Venus::Role::Tryable";
  }

  return $self;
}

# METHODS

sub catch {
  my ($self, $method, @args) = @_;

  my @result = $self->try($method, @args)->error(\my $error)->result;

  return wantarray ? ($error ? ($error, undef) : ($error, @result)) : $error;
}

sub maybe {
  my ($self, $method, @args) = @_;

  my @result = $self->try($method, @args)->error(\my $error)->result;

  return wantarray ? ($error ? (undef) : (@result)) : ($error ? undef : $result[0]);
}

# EXPORTS

sub EXPORT {
  ['catch', 'maybe']
}

1;



=head1 NAME

Venus::Role::Catchable - Catchable Role

=cut

=head1 ABSTRACT

Catchable Role for Perl 5

=cut

=head1 SYNOPSIS

  package Example;

  use Venus::Class;

  use Venus 'error';

  with 'Venus::Role::Tryable';
  with 'Venus::Role::Catchable';

  sub pass {
    true;
  }

  sub fail {
    error;
  }

  package main;

  my $example = Example->new;

  # my $error = $example->catch('fail');

=cut

=head1 DESCRIPTION

This package modifies the consuming package and provides methods for trapping
errors thrown from dispatched method calls.

=cut

=head1 METHODS

This package provides the following methods:

=cut

=head2 catch

  catch(Str $method, Any @args) (Any)

The catch method traps any errors raised by executing the dispatched method
call and returns the error string or error object. This method can return a
list of values in list-context. This method supports dispatching, i.e.
providing a method name and arguments whose return value will be acted on by
this method.

I>

=over 4

=item catch example 1

  package main;

  my $example = Example->new;

  my $catch = $example->catch('fail');

  # bless({...}, "Venus::Error")

=back

=over 4

=item catch example 2

  package main;

  my $example = Example->new;

  my $catch = $example->catch('pass');

  # undef

=back

=over 4

=item catch example 3

  package main;

  my $example = Example->new;

  my ($catch, $result) = $example->catch('pass');

  # (undef, 1)

=back

=over 4

=item catch example 4

  package main;

  my $example = Example->new;

  my ($catch, $result) = $example->catch('fail');

  # (bless({...}, "Venus::Error"), undef)

=back

=cut

=head2 maybe

  maybe(Str $method, Any @args) (Any)

The maybe method traps any errors raised by executing the dispatched method
call and returns undefined on error, effectively supressing the error. This
method can return a list of values in list-context. This method supports
dispatching, i.e.  providing a method name and arguments whose return value
will be acted on by this method.

I>

=over 4

=item maybe example 1

  package main;

  my $example = Example->new;

  my $maybe = $example->maybe('fail');

  # undef

=back

=over 4

=item maybe example 2

  package main;

  my $example = Example->new;

  my $maybe = $example->maybe('pass');

  # true

=back

=over 4

=item maybe example 3

  package main;

  my $example = Example->new;

  my (@maybe) = $example->maybe(sub {1..4});

  # (1..4)

=back

=cut

=head1 AUTHORS

Awncorp, C

=cut

=head1 LICENSE

Copyright (C) 2000, Al Newkirk.

This program is free software, you can redistribute it and/or modify it under
the terms of the Apache license version 2.0.

=cut