[project @ 2001-12-10 14:08:58 by simonmar]

[ghc-hetmet.git] / ghc / compiler / rename / ParseIface.y

diff --git a/ghc/compiler/rename/ParseIface.y b/ghc/compiler/rename/ParseIface.y
index ac0a7a3..1967e49 100644 (file)
--- a/ghc/compiler/rename/ParseIface.y
+++ b/ghc/compiler/rename/ParseIface.y
@@ -206,7 +206,8 @@ iface               : '__interface' package mod_name
                  instance_decl_part
                  decls_part
                  rules_and_deprecs_part
-                 { ParsedIface {
+                 { let (rules,deprecs) = $14 () in
+                   ParsedIface {
                        pi_mod  = mkModule $3 $2,       -- Module itself
                        pi_vers = $4,                   -- Module version
                        pi_orphan  = $6,
@@ -215,8 +216,8 @@ iface               : '__interface' package mod_name
                        pi_fixity  = $11,               -- Fixies
                        pi_insts   = $12,               -- Local instances
                        pi_decls   = $13,               -- Decls
-                       pi_rules   = (snd $5,fst $14),  -- Rules 
-                       pi_deprecs = snd $14            -- Deprecations 
+                       pi_rules   = (snd $5,rules),    -- Rules 
+                       pi_deprecs = deprecs            -- Deprecations 
                   } }
 
 -- Versions for exports and rules (optional)
@@ -363,8 +364,8 @@ maybe_idinfo  :: { RdrName -> [HsIdInfo RdrName] }
 maybe_idinfo  : {- empty -}    { \_ -> [] }
              | pragma          { \x -> if opt_IgnoreIfacePragmas then [] 
                                        else case $1 of
-                                               POk _ id_info -> id_info
-                                               PFailed err -> pprPanic "IdInfo parse failed" 
+                                               Just (POk _ id_info) -> id_info
+                                               Just (PFailed err) -> pprPanic "IdInfo parse failed" 
                                                                        (vcat [ppr x, err])
                                }
     {-
@@ -384,33 +385,32 @@ maybe_idinfo  : {- empty -}       { \_ -> [] }
        dates from a time where we picked up a .hi file first if it existed.]
     -}
 
-pragma :: { ParseResult [HsIdInfo RdrName] }
-pragma : src_loc PRAGMA        { parseIdInfo $2 PState{ bol = 0#, atbol = 1#,
+pragma :: { Maybe (ParseResult [HsIdInfo RdrName]) }
+pragma : src_loc PRAGMA        { Just (parseIdInfo $2 PState{ bol = 0#, atbol = 1#,
                                                        context = [],
                                                        glasgow_exts = 1#,
-                                                       loc = $1 }
+                                                       loc = $1 })
                                }
 
 -----------------------------------------------------------------------------
 
-rules_and_deprecs_part :: { ([RdrNameRuleDecl], IfaceDeprecs) }
-rules_and_deprecs_part : {- empty -}   { ([], Nothing) }
-                      | rules_prag     { case $1 of
-                                            POk _ rds -> rds
-                                            PFailed err -> pprPanic "Rules/Deprecations parse failed" err
-                                       }
-
-rules_prag :: { ParseResult ([RdrNameRuleDecl], IfaceDeprecs) }
-rules_prag : src_loc PRAGMA    { parseRules $2 PState{ bol = 0#, atbol = 1#,
-                                                       context = [],
-                                                       glasgow_exts = 1#,
-                                                       loc = $1 }
-                               }
+-- This production is lifted so that it doesn't get eagerly parsed when we
+-- use happy --strict.
+rules_and_deprecs_part :: { () -> ([RdrNameRuleDecl], IfaceDeprecs) }
+rules_and_deprecs_part
+  : {- empty -}                { \_ -> ([], Nothing) }
+  | src_loc PRAGMA     { \_ -> case parseRules $2 PState{ bol = 0#, atbol = 1#,
+                                                          context = [],
+                                                          glasgow_exts = 1#,
+                                                          loc = $1 } of
+                                       POk _ rds   -> rds
+                                       PFailed err -> pprPanic "Rules/Deprecations parse failed" err
+                       }
 
 rules_and_deprecs :: { ([RdrNameRuleDecl], IfaceDeprecs) }
 rules_and_deprecs : rule_prag deprec_prag      { ($1, $2) }
 
- 
+
 -----------------------------------------------------------------------------
 
 rule_prag :: { [RdrNameRuleDecl] }