Rewriting it to: concatMap ($ p)[downPar , downNew , downTrans ] gives: ($ p) =<< [downPar, downNew, downTrans] didn't check though! =@@i Edsko de Vries schreef:
Hi,
Is there a nice way to write
down :: Focus -> [Focus] down p = concat [downPar p, downNew p, downTrans p]
in point-free style? (In doesn't make much difference what these functions do; if it helps, their types are downPar, downNew, downTrans :: Focus -> [Focus]).
Ideally, I would like to write something like
down = downPar ... downNew ... downTrans
but I'm not sure what should be on the dots. This works:
down = concat . flip map [downPar, downNew, downTrans] . flip ($)
but is extremely ugly and doesn't really explain what's going on :) (It seems to me I should be able to take advantage of the list monad, somehow).
Pointers appreciated!
Edsko
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