make it possible to override opers defined in an interface by syntax 'instance Foo of Bar - [f,g,h]'

src/compiler/GF/Compile/ReadFiles.hs

@@ -178,7 +178,7 @@ importsOfModule (m,mi) = (modName m,depModInfo mi [])
     depModType (MTResource)       xs = xs
     depModType (MTInterface)      xs = xs
     depModType (MTConcrete m2)    xs = modName m2:xs
-    depModType (MTInstance m2)    xs = modName m2:xs
+    depModType (MTInstance (m2,_))    xs = modName m2:xs
 
     depExtends es xs = foldr depInclude xs es
 

src/compiler/GF/Compile/Update.hs

@@ -89,10 +89,10 @@ rebuildModule gr mo@(i,mi@(ModInfo mt stat fs_ me mw ops_ med_ js_)) = do
               ("module" +++ showIdent i +++ 
                "has open interfaces and must therefore be declared incomplete") 
       case mt of
-        MTInstance i0 -> do
+        MTInstance (i0,mincl) -> do
           m1 <- lookupModule gr i0
           testErr (isModRes m1) ("interface expected instead of" +++ showIdent i0)
-          js' <- extendMod gr False (i0,const True) i (jments m1) (jments mi)
+          js' <- extendMod gr False (i0, isInherited mincl) i (jments m1) (jments mi)
           --- to avoid double inclusions, in instance I of I0 = J0 ** ...
           case extends mi of
             []  -> return $ replaceJudgements mi js'

src/compiler/GF/Grammar/Parser.y

@@ -132,11 +132,11 @@ ComplMod
 
 ModType :: { (ModuleType,Ident) }
 ModType
-  : 'abstract'  Ident                    { (MTAbstract,      $2) } 
+  : 'abstract'  Ident                     { (MTAbstract,      $2) } 
-  | 'resource'  Ident                    { (MTResource,      $2) }
+  | 'resource'  Ident                     { (MTResource,      $2) }
-  | 'interface' Ident                    { (MTInterface,     $2) }
+  | 'interface' Ident                     { (MTInterface,     $2) }
-  | 'concrete'  Ident 'of' Ident         { (MTConcrete $4,   $2) }
+  | 'concrete'  Ident 'of' Ident          { (MTConcrete $4,   $2) }
-  | 'instance'  Ident 'of' Ident         { (MTInstance $4,   $2) }
+  | 'instance'  Ident 'of' Included       { (MTInstance $4,   $2) }
 
 ModHeaderBody :: { ( [(Ident,MInclude)]
                    , Maybe (Ident,MInclude,[(Ident,Ident)])

src/compiler/GF/Grammar/Printer.hs

@@ -61,7 +61,7 @@ ppModule q (mn, ModInfo mtype mstat opts exts with opens _ jments) =
           MTResource         -> text "resource"  <+> ppIdent mn
           MTConcrete abs     -> text "concrete"  <+> ppIdent mn <+> text "of" <+> ppIdent abs
           MTInterface        -> text "interface" <+> ppIdent mn
-          MTInstance int     -> text "instance"  <+> ppIdent mn <+> text "of" <+> ppIdent int
+          MTInstance ie      -> text "instance"  <+> ppIdent mn <+> text "of" <+> ppExtends ie
 
       ppExtends (id,MIAll        ) = ppIdent id
       ppExtends (id,MIOnly   incs) = ppIdent id              <+> brackets (commaPunct ppIdent incs)

src/compiler/GF/Infra/Dependencies.hs

@@ -58,7 +58,7 @@ grammar2moddeps monly gr = [(i,depMod i m) | (i,m) <- modules gr, yes i]
           modtype = mtype m,
           ofs     = case mtype m of 
                      MTConcrete i -> [i | yes i]
-                     MTInstance i -> [i | yes i]
+                     MTInstance (i,_) -> [i | yes i]
                      _ -> [],
           extendeds = nub $ filter yes $ map fst (extend m),
           openeds = nub $ filter yes $ map openedModule (opens m),

src/compiler/GF/Infra/Modules.hs

@@ -74,7 +74,7 @@ data ModuleType =
   | MTConcrete Ident
     -- ^ up to this, also used in GFO. Below, source only.
   | MTInterface
-  | MTInstance Ident
+  | MTInstance (Ident,MInclude)
   deriving (Eq,Show)
 
 data MInclude = MIAll | MIOnly [Ident] | MIExcept [Ident]
@@ -145,7 +145,7 @@ depPathModule m = fors m ++ exts m ++ opens m
     fors m = 
       case mtype m of
         MTConcrete i   -> [OSimple i]
-        MTInstance i   -> [OSimple i]
+        MTInstance (i,_)   -> [OSimple i]
         _              -> []
     exts m = map OSimple (extends m)
 
@@ -189,7 +189,7 @@ allExtendsPlus gr i =
     Ok m -> i : concatMap (allExtendsPlus gr) (exts m)
     _    -> []
   where
-    exts m = extends m ++ [j | MTInstance j <- [mtype m]]
+    exts m = extends m ++ [j | MTInstance (j,_) <- [mtype m]]
 
 -- | conversely: all modules that extend a given module, incl. instances of interface
 allExtensions :: MGrammar a -> Ident -> [Ident]
@@ -198,9 +198,11 @@ allExtensions gr i =
     Ok m -> let es = exts i in es ++ concatMap (allExtensions gr) es
     _    -> []
  where
-   exts i = [j | (j,m) <- mods, elem i (extends m) 
+   exts i = [j | (j,m) <- mods, elem i (extends m) || isInstanceOf i m]
-                             || elem (MTInstance i) [mtype m]]
    mods = modules gr
+   isInstanceOf i m = case mtype m of
+     MTInstance (j,_) -> j == i
+     _ -> False
 
 -- | initial search path: the nonqualified dependencies
 searchPathModule :: ModInfo a -> [Ident]