fork(2) download 
  1. import Data.Char
  2. import Control.Applicative
  3. import Control.Arrow
  4.  
  5. muntil p _ x | p x = return x
  6. muntil p f x = f x >>= muntil p f
  7.  
  8. back = first . (++)
  9.  
  10. split (p:ps) = back [p] $ case p of
  11. 	']' -> ([], ps)
  12. 	'[' -> uncurry back $ second split $ split ps
  13. 	_   -> split ps
  14.  
  15. eval'    []  st = return ([], st)
  16. eval' (p:ps) st = back [p] <$> case (p, st) of
  17. 	('>', (xs, y:ys)) -> eval' ps (y:xs, ys) 
  18. 	('<', (x:xs, ys)) -> eval' ps (xs, x:ys) 
  19. 	('+', (xs, y:ys)) -> eval' ps (xs, (y + 1):ys)
  20. 	('-', (xs, y:ys)) -> eval' ps (xs, (y - 1):ys)
  21. 	('.', (xs, y:ys)) -> putChar (chr y) >> eval' ps (xs, y:ys)
  22. 	(',', (xs, _:ys)) -> getChar >>= \y -> eval' ps (xs, ord y:ys)
  23. 	(']', st)         -> return (ps, st)
  24. 	('[', st)         -> do
  25. 		(ps', st') <- muntil (\(_, (_, y:_)) -> y == 0) (uncurry eval') (ps, st)
  26. 		let (pxs, pys) = split ps'
  27. 		back pxs <$> eval' pys st'
  28.  
  29. eval ps = eval' ps ([], repeat 0)
  30.  
  31. main = eval ">>+++++++[>++++++[>+<-]<-]+++++[>++[>>+<<-]<-]<<+++++[[>+>[-]>[-]<<[->+>+<<]>>[-<<+>>]<<>[>>.<<-]>>>.<<<<<-]]"
Success #stdin #stdout 0s 6212KB
comments (?)
stdin 
Standard input is empty
stdout 
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https://ideone.com/U3IGeh
language:
Haskell (ghc 8.4.4)
created:
11 years ago
visibility:
secret

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