use Perl

• You saw rubyisms? (Score:2)

  by Simon (89)

  rubyisms.pm has an idiomatic translation of "yield" (As well as "self" and "super"). As for perldoc -f, ri should do everything you want.
  • Re:You saw rubyisms? (Score:2)

    by Ovid (2709) on 2008.05.21 5:22 (#62965) Homepage Journal

    Actually, I can't seem to use your 'yield' as a direct translation. I'm missing something fundamental. I put together this in Ruby (very similar to my actual problem):

    class Foo
        attr_reader :val
        def initialize(val)
            @val = val
        end
        def inc(some_val)
            @val = @val + some_val
        end
    end
    
    def testy(args)
        foo = Foo.new(1)
        _testy(args, foo) {
            yield foo
        }
    end
    
    def _testy(args,somefoo)
        for item in args
            somefoo.inc(item)
            yield
        end
    end
    
    testy([1,2,3]) {|x| puts x.val}

    That, as expected, prints 2, 4 and 7. However, attempting to translate that to Perl is not only exceedingly clumsy, it also doesn't seem to work and I can't figure out why.

    #!/usr/bin/env perl
    
    use strict;
    use warnings;
    
    use rubyisms;
    
    package Foo;
    sub new { bless { val => $_[1] } => $_[0] }
    sub inc { $_[0]->{val} += $_[1] }
    sub val { shift->{val} }
    package main;
    
    sub _testy(&@);
    
    sub testy (&@) {
        my ( undef, $args ) = @_;
        my $foo  = Foo->new(1);
        _testy { yield $foo } ($args, $foo);   # line 19
    }
    
    sub _testy (&@) {
        my ( undef, $args, $somefoo ) = @_;
        for (@$args) {
            $somefoo->inc($_);
            yield;
        }
    }
    
    testy { print shift->val, $/ } ([1,2,3]);
    __END__
    no block given (LocalJumpError) at yield.pl line 19

    Reply to This

    Parent