GF.Infra.Modules: keep the modules of a grammar in a finite map instead of a list

This speeds up the compilation of PhrasebookFin.pgf by 12%, mosly by speeding
up calls to lookupModule in calls from lookupParamValues, in calls
from allParamValues.

The invariant "modules are stored in dependency order" is no longer respected!
But the type MGrammar is now abstract, making it easier to maintain this or
other invariants in the future.

src/compiler/GF/Infra/Modules.hs

@@ -15,12 +15,12 @@
 --
 -- The same structure will be used in both source code and canonical.
 -- The parameters tell what kind of data is involved.
--- Invariant: modules are stored in dependency order
 -----------------------------------------------------------------------------
 
 module GF.Infra.Modules (
-        MGrammar(..), ModInfo(..), ModuleType(..),
+        MGrammar, ModInfo(..), ModuleType(..),
         MInclude (..),
+        mGrammar,modules,
         extends, isInherited,inheritAll, 
         updateMGrammar, updateModule, replaceJudgements, addFlag,
         addOpenQualif, flagsModule, allFlags, mapModules,
@@ -28,7 +28,8 @@ module GF.Infra.Modules (
         ModuleStatus(..),
         openedModule, depPathModule, allDepsModule, partOfGrammar,
         allExtends, allExtendSpecs, allExtendsPlus, allExtensions, 
-        searchPathModule, addModule,
+        searchPathModule,
+     -- addModule,
         emptyMGrammar, emptyModInfo,
         abstractOfConcrete, abstractModOfConcrete,
         lookupModule, lookupModuleType, lookupInfo,
@@ -50,10 +51,16 @@ import Text.PrettyPrint
 
 -- The same structure will be used in both source code and canonical.
 -- The parameters tell what kind of data is involved.
--- Invariant: modules are stored in dependency order
+-- No longer maintained invariant (TH 2011-08-30):
+--      modules are stored in dependency order
 
-newtype MGrammar a = MGrammar {modules :: [(Ident,ModInfo a)]}
+--mGrammar = MGrammar
+--newtype MGrammar a = MGrammar {modules :: [(Ident,ModInfo a)]}
+
+newtype MGrammar a = MGrammar {moduleMap :: Map.Map Ident (ModInfo a)}
   deriving Show
+modules = Map.toList . moduleMap
+mGrammar = MGrammar . Map.fromList
 
 data ModInfo a = ModInfo {
     mtype   :: ModuleType,
@@ -94,9 +101,9 @@ inheritAll i = (i,MIAll)
 
 -- destructive update
 
--- | dep order preserved since old cannot depend on new
+-- | dep order preserved since old cannot depend on new (not anymore TH 2011-08-30)
 updateMGrammar :: MGrammar a -> MGrammar a -> MGrammar a
-updateMGrammar old new = MGrammar $
+updateMGrammar old new = mGrammar $
   [(i,m) | (i,m) <- os, notElem i (map fst ns)] ++ ns
  where
    os = modules old
@@ -121,7 +128,8 @@ allFlags :: MGrammar a -> Options
 allFlags gr = concatOptions [flags m | (_,m) <- modules gr]
 
 mapModules :: (ModInfo a -> ModInfo a) -> MGrammar a -> MGrammar a 
-mapModules f (MGrammar ms) = MGrammar (map (onSnd f) ms)
+--mapModules f (MGrammar ms) = MGrammar (map (onSnd f) ms)
+mapModules f (MGrammar ms) = MGrammar (fmap f ms)
 
 data OpenSpec = 
    OSimple Ident
@@ -159,7 +167,7 @@ allDepsModule gr m = iterFix add os0 where
 
 -- | select just those modules that a given one depends on, including itself
 partOfGrammar :: MGrammar a -> (Ident,ModInfo a) -> MGrammar a
-partOfGrammar gr (i,m) = MGrammar [mo | mo@(j,_) <- mods, elem j modsFor] 
+partOfGrammar gr (i,m) = mGrammar [mo | mo@(j,_) <- mods, elem j modsFor]
   where
     mods = modules gr
     modsFor = (i:) $ map openedModule $ allDepsModule gr m
@@ -208,12 +216,15 @@ allExtensions gr i =
 searchPathModule :: ModInfo a -> [Ident]
 searchPathModule m = [i | OSimple i <- depPathModule m]
 
+{-
 -- | a new module can safely be added to the end, since nothing old can depend on it
 addModule :: MGrammar a -> Ident -> ModInfo a -> MGrammar a
-addModule gr name mi = MGrammar $ (modules gr ++ [(name,mi)])
+--addModule gr name mi = MGrammar $ (modules gr ++ [(name,mi)])
+addModule gr name mi = MGrammar $ Map.insert name mi (moduleMap gr)
+-}
 
 emptyMGrammar :: MGrammar a
-emptyMGrammar = MGrammar []
+emptyMGrammar = mGrammar []
 
 emptyModInfo :: ModInfo a
 emptyModInfo = ModInfo MTResource MSComplete noOptions [] Nothing [] [] emptyBinTree
@@ -238,7 +249,8 @@ abstractModOfConcrete gr c = do
 --- canonFileName s = prt s ++ ".gfc"
 
 lookupModule :: MGrammar a -> Ident -> Err (ModInfo a)
-lookupModule gr m = case lookup m (modules gr) of
+--lookupModule gr m = case lookup m (modules gr) of
+lookupModule gr m = case Map.lookup m (moduleMap gr) of
   Just i  -> return i
   Nothing -> Bad $ render (text "unknown module" <+> ppIdent m <+> text "among" <+> hsep (map (ppIdent . fst) (modules gr)))