[commit: Cabal] master: Added a Functor instance for search trees. (42d5932)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/Cabal

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/42d5932fdf7f883139add3a9a6c8c1588aa0ab06

>---------------------------------------------------------------

commit 42d5932fdf7f883139add3a9a6c8c1588aa0ab06
Author: Andres Loeh <andres at well-typed.com>
Date:   Mon Jul 4 18:45:33 2011 +0000

    Added a Functor instance for search trees.

>---------------------------------------------------------------

 .../Distribution/Client/Dependency/Modular/Tree.hs |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/cabal-install/Distribution/Client/Dependency/Modular/Tree.hs b/cabal-install/Distribution/Client/Dependency/Modular/Tree.hs
index 954bef4..50b522d 100644
--- a/cabal-install/Distribution/Client/Dependency/Modular/Tree.hs
+++ b/cabal-install/Distribution/Client/Dependency/Modular/Tree.hs
@@ -21,6 +21,13 @@ data Tree a =
   | Fail        (ConflictSet QPN) FailReason
   deriving (Eq, Show)
 
+instance Functor Tree where
+  fmap f (PChoice qpn i   xs) = PChoice qpn (f i)   (fmap (fmap f) xs)
+  fmap f (FChoice qpn i b xs) = FChoice qpn (f i) b (fmap (fmap f) xs)
+  fmap f (GoalChoice      xs) = GoalChoice          (fmap (fmap f) xs)
+  fmap f (Done    rdm       ) = Done    rdm
+  fmap f (Fail    cs fr     ) = Fail    cs fr
+
 data FailReason = InconsistentInitialConstraints
                 | Conflicting [Dep QPN]
                 | ConflictingFlag