Allow a vew pattern or bang pattern in a record pattern.

e.g. data T = MkT { x,y :: Int } f (MkT { x = !v, y = negate -> w }) = v + w
ghc · Aug 16, 2012 · 41c7342 · 41c7342
1 parent de07bf2
commit 41c7342
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp
@@ -1752,7 +1752,11 @@
         | '..'                          { ([],   True) }
 
 fbind   :: { HsRecField RdrName (LHsExpr RdrName) }
-        : qvar '=' exp  { HsRecField $1 $3                False }
+        : qvar '=' texp { HsRecField $1 $3                False }
+                        -- RHS is a 'texp', allowing view patterns (Trac #6038)
+                        -- and, incidentaly, sections.  Eg
+                        -- f (R { x = show -> s }) = ...
+
         | qvar          { HsRecField $1 placeHolderPunRhs True }
                         -- In the punning case, use a place-holder
                         -- The renamer fills in the final value