add advice on avoiding import ambiguities

[ghc-base.git] / Data / Foldable.hs

diff --git a/Data/Foldable.hs b/Data/Foldable.hs
index 01eff04..e624c1e 100644 (file)
--- a/Data/Foldable.hs
+++ b/Data/Foldable.hs
@@ -9,6 +9,12 @@
 -- Portability :  portable
 --
 -- Class of data structures that can be folded to a summary value.
+--
+-- Many of these functions generalize "Prelude" and "Data.List"
+-- functions of the same names from lists to any 'Foldable' functor.
+-- To avoid ambiguity, either import the "Prelude" and "Data.List"
+-- hiding these names or qualify uses of these function names with an
+-- alias for this module.
 
 module Data.Foldable (
        -- * Folds