IMP_Ubiq()
-import HsSyn ( DefaultDecl(..), MonoType,
+import HsSyn ( HsDecl(..), TyDecl, ClassDecl, InstDecl, HsBinds,
+ DefaultDecl(..), HsType, IfaceSig,
HsExpr, HsLit, ArithSeqInfo, Fake, InPat)
-import RnHsSyn ( RenamedDefaultDecl(..) )
+import RnHsSyn ( RenamedHsDecl(..), RenamedDefaultDecl(..) )
import TcHsSyn ( TcIdOcc )
-import TcMonad hiding ( rnMtoTcM )
+import TcMonad
import Inst ( InstOrigin(..) )
import TcEnv ( tcLookupClassByKey )
-import TcMonoType ( tcMonoType )
+import SpecEnv ( SpecEnv )
+import TcMonoType ( tcHsType )
import TcSimplify ( tcSimplifyCheckThetas )
import TysWiredIn ( intTy, doubleTy, unitTy )
import Unique ( numClassKey )
+import Pretty ( ppStr, ppAboves )
+import ErrUtils ( addShortErrLocLine )
import Util
\end{code}
\begin{code}
-tcDefaults :: [RenamedDefaultDecl]
+default_default = [intTy, doubleTy] -- language-specified default `default'
+
+tcDefaults :: [RenamedHsDecl]
-> TcM s [Type] -- defaulting types to heave
-- into Tc monad for later use
-- in Disambig.
+tcDefaults decls = tc_defaults [default_decl | DefD default_decl <- decls]
-tcDefaults []
- = returnTc [intTy, doubleTy] -- language-specified default `default'
+tc_defaults [] = returnTc default_default
-tcDefaults [DefaultDecl mono_tys locn]
+tc_defaults [DefaultDecl mono_tys locn]
= tcAddSrcLoc locn $
- mapTc tcMonoType mono_tys `thenTc` \ tau_tys ->
+ mapTc tcHsType mono_tys `thenTc` \ tau_tys ->
case tau_tys of
[] -> returnTc [] -- no defaults
returnTc tau_tys
+tc_defaults decls
+ = failTc (dupDefaultDeclErr decls)
+
+
+dupDefaultDeclErr (DefaultDecl _ locn1 : dup_things) sty
+ = ppAboves (item1 : map dup_item dup_things)
+ where
+ item1
+ = addShortErrLocLine locn1 (\ sty ->
+ ppStr "multiple default declarations") sty
+
+ dup_item (DefaultDecl _ locn)
+ = addShortErrLocLine locn (\ sty ->
+ ppStr "here was another default declaration") sty
+
\end{code}