More compact error messages for record selectors

Make recSelError generate the standard part of the record selector
error message (i.e. "No match in record selector") rather than have
that string duplicated for every record selector.

diff --git a/Control/Exception/Base.hs b/Control/Exception/Base.hs
index b6893fb..f9f20f8 100644 (file)
--- a/Control/Exception/Base.hs
+++ b/Control/Exception/Base.hs
@@ -669,8 +669,9 @@ recSelError, recConError, irrefutPatError, runtimeError,
              nonExhaustiveGuardsError, patError, noMethodBindingError
         :: Addr# -> a   -- All take a UTF8-encoded C string
 
-recSelError              s = throw (RecSelError (unpackCStringUtf8# s)) -- No location info unfortunately
-runtimeError             s = error (unpackCStringUtf8# s)               -- No location info unfortunately
+recSelError              s = throw (RecSelError ("No match in record selector "
+                                                ++ unpackCStringUtf8# s))  -- No location info unfortunately
+runtimeError             s = error (unpackCStringUtf8# s)                   -- No location info unfortunately
 
 nonExhaustiveGuardsError s = throw (PatternMatchFail (untangle s "Non-exhaustive guards in"))
 irrefutPatError          s = throw (PatternMatchFail (untangle s "Irrefutable pattern failed for pattern"))