Pattern-matching constructors
\begin{code}
+{-# OPTIONS -fno-warn-incomplete-patterns #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module MatchCon ( matchConFamily ) where
#include "HsVersions.h"
import DsUtils
import Util ( takeList )
import Id
+import Var (TyVar)
import SrcLoc
import Outputable
\end{code}
= do { alts <- mapM (matchOneCon vars ty) groups
; return (mkCoAlgCaseMatchResult var ty alts) }
+matchOneCon :: [Id]
+ -> Type
+ -> [EquationInfo]
+ -> DsM (DataCon, [TyVar], MatchResult)
matchOneCon vars ty (eqn1 : eqns) -- All eqns for a single constructor
= do { (wraps, eqns') <- mapAndUnzipM shift (eqn1:eqns)
; arg_vars <- selectMatchVars (take (dataConSourceArity con1)
-- are probably never looked at anyway
-> HsConDetails (LPat Id) (HsRecFields Id (LPat Id))
-> [Pat Id]
-conArgPats data_con arg_tys (PrefixCon ps) = map unLoc ps
-conArgPats data_con arg_tys (InfixCon p1 p2) = [unLoc p1, unLoc p2]
-conArgPats data_con arg_tys (RecCon (HsRecFields rpats _))
+conArgPats _data_con _arg_tys (PrefixCon ps) = map unLoc ps
+conArgPats _data_con _arg_tys (InfixCon p1 p2) = [unLoc p1, unLoc p2]
+conArgPats data_con arg_tys (RecCon (HsRecFields rpats _))
| null rpats
= -- Special case for C {}, which can be used for
-- a constructor that isn't declared to have