New syntax for stand-alone deriving. Implemented fully.

[ghc-hetmet.git] / compiler / typecheck / TcInstDcls.lhs

diff --git a/compiler/typecheck/TcInstDcls.lhs b/compiler/typecheck/TcInstDcls.lhs
index 880a0ee..3236b67 100644 (file)
--- a/compiler/typecheck/TcInstDcls.lhs
+++ b/compiler/typecheck/TcInstDcls.lhs
@@ -146,12 +146,13 @@ Gather up the instance declarations from their various sources
 tcInstDecls1   -- Deal with both source-code and imported instance decls
    :: [LTyClDecl Name]         -- For deriving stuff
    -> [LInstDecl Name]         -- Source code instance decls
+   -> [LDerivDecl Name]                -- Source code stand-alone deriving decls
    -> TcM (TcGblEnv,           -- The full inst env
           [InstInfo],          -- Source-code instance decls to process; 
                                -- contains all dfuns for this module
           HsValBinds Name)     -- Supporting bindings for derived instances
 
-tcInstDecls1 tycl_decls inst_decls
+tcInstDecls1 tycl_decls inst_decls deriv_decls
   = checkNoErrs $
     do {        -- Stop if addInstInfos etc discovers any errors
                -- (they recover, so that we get more than one error each
@@ -178,14 +179,11 @@ tcInstDecls1 tycl_decls inst_decls
                -- (3) Instances from generic class declarations
        ; generic_inst_info <- getGenericInstances clas_decls
 
-               -- Next, construct the instance environment so far, consisting
-               -- of 
-               --   a) local instance decls
-               --   b) generic instances
-               --   c) local family instance decls
-       ; addInsts local_info         $ do {
-       ; addInsts generic_inst_info  $ do {
-       ; addFamInsts at_idx_tycon    $ do {
+       -- (3) Compute instances from "deriving" clauses; 
+       -- This stuff computes a context for the derived instance decl, so it
+       -- needs to know about all the instances possible; hence inst_env4
+    tcDeriving tycl_decls      `thenM` \ (deriv_inst_info, deriv_binds) ->
+    addInsts deriv_inst_info   $
 
                -- (4) Compute instances from "deriving" clauses; 
                -- This stuff computes a context for the derived instance