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📝 the Fresh constructors.

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Rob Rix 2017-12-21 10:54:40 -05:00
parent 32215499f0
commit 434dd829b3
1 changed files with 2 additions and 2 deletions
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src/Control/Monad/Effect/Fresh.hs
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@ -8,8 +8,8 @@ type TName = Int
-- | An effect offering a (resettable) sequence of always-incrementing, and therefore “fresh,” type variables.
data Fresh a where
Reset :: TName -> Fresh ()
Fresh :: Fresh TName
Reset :: TName -> Fresh () -- ^ Reset the sequence of variable names. Useful to avoid complicated alpha-equivalence comparisons when iteratively recomputing the results of an analysis til convergence.
Fresh :: Fresh TName -- ^ Get a fresh variable name, guaranteed unused since the last reset.
class Monad m => MonadFresh m where
fresh :: m TName