[project @ 2003-02-14 13:01:32 by simonpj]

Fix for deriving of records with leading underscore, and corresponding lex

diff --git a/ghc/compiler/typecheck/TcGenDeriv.lhs b/ghc/compiler/typecheck/TcGenDeriv.lhs
index ac6abdf..bafa008 100644 (file)
--- a/ghc/compiler/typecheck/TcGenDeriv.lhs
+++ b/ghc/compiler/typecheck/TcGenDeriv.lhs
@@ -854,10 +854,11 @@ gen_Read_binds get_fixity tycon
                        BindStmt (VarPat a) (mkHsVarApps reset_RDR [readPrec_RDR]) loc]
 
        -- When reading field labels we might encounter
-       --      a = 3
+       --      a  = 3
+       --      _a = 3
        -- or   (#) = 4
        -- Note the parens!
-    read_lbl lbl | isAlpha (head lbl_str) 
+    read_lbl lbl | is_id_start (head lbl_str) 
                 = [bindLex (ident_pat lbl_lit)]
                 | otherwise
                 = [read_punc "(", 
@@ -866,6 +867,7 @@ gen_Read_binds get_fixity tycon
                 where  
                   lbl_str = occNameUserString (getOccName (fieldLabelName lbl)) 
                   lbl_lit = mkHsString lbl_str
+                  is_id_start c = isAlpha c || c == '_'
 \end{code}