Pattern matching on booleans

[darthdeus]

I'm not really sure if I'm missing something, but why are you using case to pattern match on a boolean in the Haskell source, when all of those

case isVisited of
  True -> ...
  False -> ...

could be replaced by simple if isVisited then ... else ...?

[logicchains]

I just personally find pattern matching like that more aesthetically pleasing than the if then else construct. I assumed there wouldn't be any performance difference.