Day 19: Aplenty

Megathread guidelines

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FAQ

  • @sjmulder
    2•11 months ago

    That’s a nice parser and I like the use of pattern matching here.

    What I wonder is if you couldn’t make a cool monadic representation of the ranges, where you could do the equivalent of

    if (foo.x > 12)
    return bar(x);
else
    return baz(x);

    but ‘x’ wouldn’t be an integer, it’d be a collection of integer ranges. The > operator would return a collection of pairs of (newly split) integer ranges and booleans. The if would yield map the pairs to a new bunch of pairs and so on.

    • Leo Uino
      2•11 months ago

      Mmm, I was thinking something similar. I’ve been meaning to go back and have another go, but the last few problems have eaten up all my time (and energy!)

      I realized with the parser you can write eg

          rule = (,) <$> optionMaybe (try condition) <*> many1 letter

      which avoids even more of those pesky variable names! (I still haven’t quite internalized how to use Applicative)