Some changed/new utility functions

GF.Data.Utilities:  Rename mapFst to apFst, mapSnd to apSnd.
		    Add apBoth, mapFst, mapSnd, mapBoth.
GF.Data.Operations: Remove onSnd (same as apSnd)

src/compiler/GF/Data/Operations.hs

@@ -15,7 +15,7 @@
 -----------------------------------------------------------------------------
 
 module GF.Data.Operations (-- * misc functions
-		   ifNull, onSnd,
+		   ifNull,
 
 		   -- * the Error monad
 		   Err(..), err, maybeErr, testErr, errVal, errIn, 
@@ -76,9 +76,6 @@ infixr 5 +++++
 ifNull :: b -> ([a] -> b) -> [a] -> b
 ifNull b f xs = if null xs then b else f xs
 
-onSnd :: (a -> b) -> (c,a) -> (c,b)
-onSnd f (x, y) = (x, f y)
-
 -- the Error monad
 
 -- | analogue of @maybe@

src/compiler/GF/Data/Utilities.hs

@@ -130,11 +130,20 @@ both f g x y = g (f x) (f y)
 
 -- * functions on pairs
 
-mapFst :: (a -> a') -> (a, b) -> (a', b)
-mapFst f (a, b) = (f a, b)
+apFst :: (a -> a') -> (a, b) -> (a', b)
+apFst f (a, b) = (f a, b)
 
-mapSnd :: (b -> b') -> (a, b) -> (a, b')
-mapSnd f (a, b) = (a, f b)
+apSnd :: (b -> b') -> (a, b) -> (a, b')
+apSnd f (a, b) = (a, f b)
+
+apBoth :: (a -> b) -> (a, a) -> (b, b)
+apBoth f (x, y) = (f x, f y)
+
+-- * functions on lists of pairs
+
+mapFst = map . apFst
+mapSnd = map . apSnd
+mapBoth = map . apBoth
 
 -- * functions on monads