Fix Trac #2529: derived read for prefix constructor operators

diff --git a/compiler/typecheck/TcGenDeriv.lhs b/compiler/typecheck/TcGenDeriv.lhs
index 817e813..0eabe32 100644 (file)
--- a/compiler/typecheck/TcGenDeriv.lhs
+++ b/compiler/typecheck/TcGenDeriv.lhs
@@ -843,22 +843,26 @@ gen_Read_binds get_fixity loc tycon
        con_str = data_con_str data_con
        
        prefix_parser = mk_parser prefix_prec prefix_stmts body
-               prefix_stmts            -- T a b c
-                 = (if not (isSym con_str) then
-                 [bindLex (ident_pat con_str)]
-            else [read_punc "(", bindLex (symbol_pat con_str), read_punc ")"])
-                   ++ read_args
+
+       read_prefix_con
+           | isSym con_str = [read_punc "(", bindLex (symbol_pat con_str), read_punc ")"]
+           | otherwise     = [bindLex (ident_pat con_str)]
         
+       read_infix_con
+           | isSym con_str = [bindLex (symbol_pat con_str)]
+           | otherwise     = [read_punc "`", bindLex (ident_pat con_str), read_punc "`"]
+
+               prefix_stmts            -- T a b c
+                 = read_prefix_con ++ read_args
+
                infix_stmts             -- a %% b, or  a `T` b 
                  = [read_a1]
-           ++  (if isSym con_str
-                then [bindLex (symbol_pat con_str)]
-                else [read_punc "`", bindLex (ident_pat con_str), read_punc "`"])
+           ++ read_infix_con
            ++ [read_a2]
      
                record_stmts            -- T { f1 = a, f2 = b }
-                 = [bindLex (ident_pat (wrapOpParens con_str)),
-                    read_punc "{"]
+                 = read_prefix_con 
+           ++ [read_punc "{"]
                    ++ concat (intersperse [read_punc ","] field_stmts)
                    ++ [read_punc "}"]