Add note explaining why we use a different <>

haskell · Jan 4, 2012 · f615a6a · f615a6a
1 parent f642dc4
commit f615a6a
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/Text/PrettyPrint/HughesPJ.hs b/Text/PrettyPrint/HughesPJ.hs
@@ -543,6 +543,10 @@ nilAboveNest g k q           | not g && k > 0      -- No newline if no overlap
 -- ---------------------------------------------------------------------------
 -- Horizontal composition @<>@
 
+-- We intentionally avoid Data.Monoid.(<>) here due to interactions of
+-- Data.Monoid.(<>) and (<+>).  See
+-- http://www.haskell.org/pipermail/libraries/2011-November/017066.html
+
 -- | Beside.
 -- '<>' is associative, with identity 'empty'.
 (<>) :: Doc -> Doc -> Doc