use Perl

• Text::Pipe? (Score:1)

  by hanekomu (8123) on 2007.10.04 3:48 (#58203) Homepage Journal

  I like the "more ideal" solution of having separate text filters. Since Text::Filter is taken, how about Text::Pipe? After all, the factory method shouldn't be able to just give you one filter, but several filters, piped together.
  
  And I wouldn't put the factory in a ::Common module; just call it Text::Pipe::Factory. It generates "pipe segments" that are Text::Pipe::* objects, all of which are derived from Text::Pipe::Base.
  
  Several pipe segments, piped together, could themselves be pipe segments.
  
  Text::Pipe::* objects could have '|' overloaded so you can combine them in a TT-like syntax.
  
  Then again, maybe you don't want to limit yourself to piping text; how about arbitrary data structures? E.g., one pipe segment could take an array and reduce(). But maybe that's going too far. (I've had such an idea many years ago but didn't follow up on it.) Piping text is fine.
  
  Your example regex that deals with erroneous spaces would itself by a pipe segment, something like Text::Pipe::Trim.
  

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  • Re: (Score:2)

    by miyagawa (1653)

    I don't care much about names, but I disagree letting Text::Pipe itself have the stackable several filters becasue all filters have the same single filter interface, you don't need to.
    
    Creating a stacked pipe is easy by creating a new Pipe stacker object, like:

    use Text::Pipe::Stackable;
    use Text::Pipe;
     
    my $pipe1 = Text::Pipe->new('foo');
    my $pipe2 = Text::Pipe->new('bar');
    my $pipe3 = Text::Pipe->new('baz');
     
    my $stacked_pipe = Text::Pipe::Stackable->new($pipe1, $pipe2, $pipe3);
     
    • Re: (Score:1)

      by hanekomu (8123)

      Agreed re bike-shed discussion; one more point though:
      
              my $stacked_pipe = Text::Pipe::Stackable->new($pipe1, $pipe2, $pipe3);
      
      Yes, that's a better design pattern. In that case, Text::Pipe::Stackable->new() should be able to take both individual segments as well as Text::Pipe::Stackable objects as well (for a kind of recursive construction).
      
      That is, stacked pipes should - to the user - be indistinguishable from individual pipe segments. It's just some black hole that has an i
      • Re: (Score:2)

        by miyagawa (1653)

        Yeah, it's caled Composite design pattern and also a Decorator.