use Perl

• refining the "show" function (Score:1)

  by dpuu (6090)

  Nice work, but still something lacking in the "show" function: both your version and SF's have too much repetition. What we really want to to say that there's a list of three actions to perform in one of three orders, with only one of the blocks moving. something like:
  
  sub show(%tree, Traversal $method) {
      return unless %tree;
      my @actions = (
          { show %tree<RIGHT>, $method },
          { show %tree<LEFT>, $method },
   
  • Re: (Score:1)

    by masak (6289)

    It's clearly a matter of taste of where you want to end up on the readability/non-repetitiousness scale. :) I simply chose to err on the side of readability this time around.
    • Re: (Score:1)

      by dpuu (6090)

      And actually I made a horrible error in my code: the way I wrote it the traversal order is actually undefined, because the order of iteration of hyper operators is undefined. So, although I'd say that having a concurrent traversal ordering would be a nice addition, the last line of my sub should probably be something like: ".() for @actions;"
  • Re: (Score:1)

    by geoffrey (5895)

    Am I the only one whose OCD goes on overdrive everytime he sees a fixed-function tree traversal sub?

    I immediately want to refactor &show into a general traversal sub:

    sub traverse(%tree, Traversal $order, &function) { ... &function(%tree<VALUE>); ... }

    and a trivial driver:

    sub show(%tree, Traversal $order) { traverse(%tree, $order, &take) }

    I guess that gets away from keeping the same overall form as the E02 code. Of course, I had the same reaction the first time I
    • Re: (Score:1)

      by masak (6289)

      Heh. The reaction I got on #perl6 was that I had changed the function too much by replacing print by take, essentially turning the &show function into an iterator generator.