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"Committed_by_peb"

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peb
2005-02-24 10:46:37 +00:00
parent 0137dd5511
commit bf436aebaa
43 changed files with 786 additions and 493 deletions
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8
src/GF/Data/Zipper.hs
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@@ -5,9 +5,9 @@
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/02/18 19:21:16 $
-- > CVS $Date: 2005/02/24 11:46:36 $
-- > CVS $Author: peb $
-- > CVS $Revision: 1.6 $
-- > CVS $Revision: 1.7 $
--
-- Gérard Huet's zipper (JFP 7 (1997)). AR 10\/8\/2001
-----------------------------------------------------------------------------
@@ -62,6 +62,7 @@ data Path a =
| Node ([Tr a], (Path a, a), [Tr a])
deriving Show
leaf :: a -> Tr a
leaf a = Tr (a,[])
newtype Loc a = Loc (Tr a, Path a) deriving Show
@@ -132,6 +133,7 @@ goBackN i st
-- added mappings between locations and trees
loc2tree :: Loc a -> Tr a
loc2tree (Loc (t,p)) = case p of
Top -> t
Node (left,(p',v),right) ->
@@ -143,8 +145,10 @@ loc2treeMarked (Loc (Tr (a,ts),p)) =
where
(mark, nomark) = (\a -> (a,True), \a -> (a, False))
tree2loc :: Tr a -> Loc a
tree2loc t = Loc (t,Top)
goRoot :: Loc a -> Loc a
goRoot = tree2loc . loc2tree
goLast :: Loc a -> Err (Loc a)