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annotate lib/ur/monad.ur @ 905:7a4b026e45dd

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Library improvements; proper list [un]urlification; remove server-side ServerCalls; eta reduction in type inference
author Adam Chlipala <adamc@hcoop.net>
date Sun, 09 Aug 2009 16:13:27 -0400
parents d1d0b18afd3d
children 8e540df3294d
rev   line source
adamc@834 1 fun exec [m ::: Type -> Type] (_ : monad m) [ts ::: {Type}] r (fd : folder ts) =
adamc@834 2 foldR [m] [fn ts => m $ts]
adamc@834 3 (fn [nm :: Name] [v :: Type] [rest :: {Type}] [[nm] ~ rest] action acc =>
adamc@834 4 this <- action;
adamc@834 5 others <- acc;
adamc@834 6 return ({nm = this} ++ others))
adamc@834 7 (return {}) [ts] fd r
adamc@898 8
adamc@898 9 fun ignore [m ::: Type -> Type] (_ : monad m) [t] (v : m t) = x <- v; return ()
adamc@905 10
adamc@905 11 fun foldR [K] [m] (_ : monad m) [tf :: K -> Type] [tr :: {K} -> Type]
adamc@905 12 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@905 13 -> [[nm] ~ rest] =>
adamc@905 14 tf t -> tr rest -> m (tr ([nm = t] ++ rest)))
adamc@905 15 (i : tr []) [r :: {K}] (fl : folder r) =
adamc@905 16 Top.fold [fn r :: {K} => $(map tf r) -> m (tr r)]
adamc@905 17 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@905 18 (acc : _ -> m (tr rest)) r =>
adamc@905 19 acc' <- acc (r -- nm);
adamc@905 20 f [nm] [t] [rest] ! r.nm acc')
adamc@905 21 (fn _ => return i)
adamc@905 22 [_] fl
adamc@905 23
adamc@905 24 fun foldR2 [K] [m] (_ : monad m) [tf1 :: K -> Type] [tf2 :: K -> Type] [tr :: {K} -> Type]
adamc@905 25 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@905 26 -> [[nm] ~ rest] =>
adamc@905 27 tf1 t -> tf2 t -> tr rest -> m (tr ([nm = t] ++ rest)))
adamc@905 28 (i : tr []) [r :: {K}] (fl : folder r) =
adamc@905 29 Top.fold [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> m (tr r)]
adamc@905 30 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@905 31 (acc : _ -> _ -> m (tr rest)) r1 r2 =>
adamc@905 32 acc' <- acc (r1 -- nm) (r2 -- nm);
adamc@905 33 f [nm] [t] [rest] ! r1.nm r2.nm acc')
adamc@905 34 (fn _ _ => return i)
adamc@905 35 [_] fl
adamc@905 36
adamc@905 37 fun mapR [K] [m] (_ : monad m) [tf :: K -> Type] [tr :: K -> Type]
adamc@905 38 (f : nm :: Name -> t :: K -> tf t -> m (tr t)) =
adamc@905 39 @@foldR [m] _ [tf] [fn r => $(map tr r)]
adamc@905 40 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] (v : tf t)
adamc@905 41 (acc : $(map tr rest)) =>
adamc@905 42 v' <- f [nm] [t] v;
adamc@905 43 return (acc ++ {nm = v'}))
adamc@905 44 {}