+
+-- Multiple case alt are be conditional assignments and have only wild
+-- binders in the alts and only variables in the case values and a variable
+-- for a scrutinee. We check the constructor of the second alt, since the
+-- first is the default case, if there is any.
+mkConcSm (bndr, (Case (Var scrut) b ty [(_, _, Var false), (con, _, Var true)])) =
+ let
+ cond_expr = (varToVHDLExpr scrut) AST.:=: (conToVHDLExpr con)
+ true_expr = (varToVHDLExpr true)
+ false_expr = (varToVHDLExpr false)
+ in
+ return $ mkCondAssign bndr cond_expr true_expr false_expr
+mkConcSm (_, (Case (Var _) _ _ alts)) = error "VHDL.mkConcSm Not in normal form: Case statement with more than two alternatives"
+mkConcSm (_, Case _ _ _ _) = error "VHDL.mkConcSm Not in normal form: Case statement has does not have a simple variable as scrutinee"
+
+-- Create an unconditional assignment statement
+mkUncondAssign ::
+ CoreBndr -- ^ The signal to assign to
+ -> AST.Expr -- ^ The expression to assign
+ -> AST.ConcSm -- ^ The resulting concurrent statement
+mkUncondAssign bndr expr = mkAssign bndr Nothing expr
+
+-- Create a conditional assignment statement
+mkCondAssign ::
+ CoreBndr -- ^ The signal to assign to
+ -> AST.Expr -- ^ The condition
+ -> AST.Expr -- ^ The value when true
+ -> AST.Expr -- ^ The value when false
+ -> AST.ConcSm -- ^ The resulting concurrent statement
+mkCondAssign bndr cond true false = mkAssign bndr (Just (cond, true)) false
+
+-- Create a conditional or unconditional assignment statement
+mkAssign ::
+ CoreBndr -> -- ^ The signal to assign to
+ Maybe (AST.Expr , AST.Expr) -> -- ^ Optionally, the condition to test for
+ -- and the value to assign when true.
+ AST.Expr -> -- ^ The value to assign when false or no condition
+ AST.ConcSm -- ^ The resulting concurrent statement
+
+mkAssign bndr cond false_expr =
+ let
+ -- I'm not 100% how this assignment AST works, but this gets us what we
+ -- want...
+ whenelse = case cond of
+ Just (cond_expr, true_expr) ->
+ let
+ true_wform = AST.Wform [AST.WformElem true_expr Nothing]
+ in
+ [AST.WhenElse true_wform cond_expr]
+ Nothing -> []
+ false_wform = AST.Wform [AST.WformElem false_expr Nothing]
+ dst_name = AST.NSimple (bndrToVHDLId bndr)
+ assign = dst_name AST.:<==: (AST.ConWforms whenelse false_wform Nothing)
+ in
+ AST.CSSASm assign
+
+-- Finds the field labels for VHDL type generated for the given Core type,
+-- which must result in a record type.
+getFieldLabels :: Type.Type -> VHDLState [AST.VHDLId]
+getFieldLabels ty = do
+ -- Ensure that the type is generated (but throw away it's VHDLId)
+ vhdl_ty ty
+ -- Get the types map, lookup and unpack the VHDL TypeDef
+ types <- getA vsTypes
+ case Map.lookup (OrdType ty) types of
+ Just (_, AST.TDR (AST.RecordTypeDef elems)) -> return $ map (\(AST.ElementDec id _) -> id) elems
+ _ -> error $ "VHDL.getFieldLabels Type not found or not a record type? This should not happen! Type: " ++ (show ty)
+
+-- Turn a variable reference into a AST expression
+varToVHDLExpr :: Var.Var -> AST.Expr
+varToVHDLExpr var = AST.PrimName $ AST.NSimple $ bndrToVHDLId var
+
+-- Turn a constructor into an AST expression. For dataconstructors, this is
+-- only the constructor itself, not any arguments it has. Should not be called
+-- with a DEFAULT constructor.
+conToVHDLExpr :: CoreSyn.AltCon -> AST.Expr
+conToVHDLExpr (DataAlt dc) = AST.PrimLit lit
+ where
+ tycon = DataCon.dataConTyCon dc
+ tyname = TyCon.tyConName tycon
+ dcname = DataCon.dataConName dc
+ lit = case Name.getOccString tyname of
+ -- TODO: Do something more robust than string matching
+ "Bit" -> case Name.getOccString dcname of "High" -> "'1'"; "Low" -> "'0'"
+ "Bool" -> case Name.getOccString dcname of "True" -> "true"; "False" -> "false"
+conToVHDLExpr (LitAlt _) = error "VHDL.conToVHDLExpr Literals not support in case alternatives yet"
+conToVHDLExpr DEFAULT = error "VHDL.conToVHDLExpr DEFAULT alternative should not occur here!"
+
+
+
+{-