%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcGenDeriv]{Generating derived instance declarations}
This is where we do all the grimy bindings' generation.
\begin{code}
-#include "HsVersions.h"
-
module TcGenDeriv (
gen_Bounded_binds,
gen_Enum_binds,
- gen_Eval_binds,
gen_Eq_binds,
gen_Ix_binds,
gen_Ord_binds,
TagThingWanted(..)
) where
-IMP_Ubiq()
-IMPORT_1_3(List(partition))
+#include "HsVersions.h"
-import HsSyn ( HsBinds(..), MonoBinds(..), Match(..), GRHSsAndBinds(..),
- GRHS(..), HsExpr(..), HsLit(..), InPat(..), Stmt(..), DoOrListComp(..),
- SYN_IE(RecFlag), recursive,
- ArithSeqInfo, Sig, HsType, FixityDecl, Fixity, Fake )
-import RdrHsSyn ( RdrName(..), varQual, varUnqual, mkOpApp,
- SYN_IE(RdrNameMonoBinds), SYN_IE(RdrNameHsExpr), SYN_IE(RdrNamePat)
+import HsSyn ( InPat(..), HsExpr(..), MonoBinds(..),
+ Match(..), GRHSsAndBinds(..), Stmt(..), HsLit(..),
+ HsBinds(..), StmtCtxt(..),
+ unguardedRHS
)
-import BasicTypes ( IfaceFlavour(..) )
-import Id ( GenId, isNullaryDataCon, dataConTag,
+import RdrHsSyn ( RdrName(..), varUnqual, mkOpApp,
+ RdrNameMonoBinds, RdrNameHsExpr, RdrNamePat
+ )
+import BasicTypes ( IfaceFlavour(..), RecFlag(..) )
+import FieldLabel ( fieldLabelName )
+import DataCon ( isNullaryDataCon, dataConTag,
dataConRawArgTys, fIRST_TAG,
- isDataCon, SYN_IE(DataCon), SYN_IE(ConTag),
- SYN_IE(Id) )
-import Maybes ( maybeToBool )
-import Name ( getOccString, getOccName, getSrcLoc, occNameString, modAndOcc, OccName, Name )
+ DataCon, ConTag,
+ dataConFieldLabels )
+import Name ( getOccString, getOccName, getSrcLoc, occNameString,
+ modAndOcc, OccName, Name )
import PrimOp ( PrimOp(..) )
import PrelInfo -- Lots of RdrNames
import SrcLoc ( mkGeneratedSrcLoc, SrcLoc )
-import TyCon ( TyCon, isNewTyCon, tyConDataCons, isEnumerationTyCon, maybeTyConSingleCon )
-import Type ( eqTy, isPrimType, SYN_IE(Type) )
+import TyCon ( TyCon, isNewTyCon, tyConDataCons, isEnumerationTyCon,
+ maybeTyConSingleCon
+ )
+import Type ( isUnLiftedType, isUnboxedType, Type )
import TysPrim ( charPrimTy, intPrimTy, wordPrimTy, addrPrimTy,
floatPrimTy, doublePrimTy
)
-import Util ( mapAccumL, zipEqual, zipWith3Equal, nOfThem, panic, assertPanic )
+import Util ( mapAccumL, zipEqual, zipWithEqual,
+ zipWith3Equal, nOfThem, panic, assertPanic )
+import Maybes ( maybeToBool )
+import List ( partition, intersperse )
\end{code}
%************************************************************************
produced don't get through the typechecker.
\end{itemize}
+
+deriveEq :: RdrName -- Class
+ -> RdrName -- Type constructor
+ -> [ (RdrName, [RdrType]) ] -- Constructors
+ -> (RdrContext, -- Context for the inst decl
+ [RdrBind], -- Binds in the inst decl
+ [RdrBind]) -- Extra value bindings outside
+
+deriveEq clas tycon constrs
+ = (context, [eq_bind, ne_bind], [])
+ where
+ context = [(clas, [ty]) | (_, tys) <- constrs, ty <- tys]
+
+ ne_bind = mkBind
+ (nullary_cons, non_nullary_cons) = partition is_nullary constrs
+ is_nullary (_, args) = null args
+
\begin{code}
gen_Eq_binds :: TyCon -> RdrNameMonoBinds
Again, we must be careful about unboxed comparisons. For example,
if \tr{a1} and \tr{a2} were \tr{Int#}s in the 2nd example above, we'd need to
generate:
+
\begin{verbatim}
cmp_eq lt eq gt (O2 a1) (O2 a2)
= compareInt# a1 a2
\end{verbatim}
\end{itemize}
+If there is only one constructor in the Data Type we don't need the WildCard Pattern.
+JJQC-30-Nov-1997
+
\begin{code}
gen_Ord_binds :: TyCon -> RdrNameMonoBinds
-- So we need to do a less-than comparison on the tags
(cmp_tags_Expr ltH_Int_RDR ah_RDR bh_RDR ltTag_Expr gtTag_Expr)))
+ tycon_data_cons = tyConDataCons tycon
(nullary_cons, nonnullary_cons)
| isNewTyCon tycon = ([], tyConDataCons tycon)
- | otherwise = partition isNullaryDataCon (tyConDataCons tycon)
-
- cmp_eq
- = mk_FunMonoBind tycon_loc cmp_eq_RDR (map pats_etc nonnullary_cons ++
- [([WildPatIn, WildPatIn], default_rhs)])
+ | otherwise = partition isNullaryDataCon tycon_data_cons
+
+ cmp_eq =
+ mk_FunMonoBind tycon_loc
+ cmp_eq_RDR
+ (if null nonnullary_cons && (length nullary_cons == 1) then
+ -- catch this specially to avoid warnings
+ -- about overlapping patterns from the desugarer.
+ let
+ data_con = head nullary_cons
+ data_con_RDR = qual_orig_name data_con
+ pat = ConPatIn data_con_RDR []
+ in
+ [([pat,pat], eqTag_Expr)]
+ else
+ map pats_etc nonnullary_cons ++
+ -- leave out wildcards to silence desugarer.
+ (if length tycon_data_cons == 1 then
+ []
+ else
+ [([WildPatIn, WildPatIn], default_rhs)]))
where
pats_etc data_con
= ([con1_pat, con2_pat],
%************************************************************************
%* *
-\subsubsection{Generating @Eval@ instance declarations}
-%* *
-%************************************************************************
-
-\begin{code}
-gen_Eval_binds tycon = EmptyMonoBinds
-\end{code}
-
-%************************************************************************
-%* *
\subsubsection{Generating @Bounded@ instance declarations}
%* *
%************************************************************************
enum_index `AndMonoBinds` enum_inRange
enum_range
- = mk_easy_FunMonoBind tycon_loc range_RDR [TuplePatIn [a_Pat, b_Pat]] [] $
+ = mk_easy_FunMonoBind tycon_loc range_RDR
+ [TuplePatIn [a_Pat, b_Pat] True{-boxed-}] [] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
untag_Expr tycon [(b_RDR, bh_RDR)] $
HsApp (mk_easy_App map_RDR [tag2con_RDR tycon]) $
(mk_easy_App mkInt_RDR [bh_RDR]))
enum_index
- = mk_easy_FunMonoBind tycon_loc index_RDR [AsPatIn c_RDR (TuplePatIn [a_Pat, b_Pat]), d_Pat] [] (
+ = mk_easy_FunMonoBind tycon_loc index_RDR
+ [AsPatIn c_RDR (TuplePatIn [a_Pat, b_Pat] True{-boxed-}),
+ d_Pat] [] (
HsIf (HsPar (mk_easy_App inRange_RDR [c_RDR, d_RDR])) (
untag_Expr tycon [(a_RDR, ah_RDR)] (
untag_Expr tycon [(d_RDR, dh_RDR)] (
let
- grhs = [OtherwiseGRHS (mk_easy_App mkInt_RDR [c_RDR]) tycon_loc]
+ grhs = unguardedRHS (mk_easy_App mkInt_RDR [c_RDR]) tycon_loc
in
HsCase
(genOpApp (HsVar dh_RDR) minusH_RDR (HsVar ah_RDR))
tycon_loc)
enum_inRange
- = mk_easy_FunMonoBind tycon_loc inRange_RDR [TuplePatIn [a_Pat, b_Pat], c_Pat] [] (
+ = mk_easy_FunMonoBind tycon_loc inRange_RDR
+ [TuplePatIn [a_Pat, b_Pat] True{-boxed-}, c_Pat] [] (
untag_Expr tycon [(a_RDR, ah_RDR)] (
untag_Expr tycon [(b_RDR, bh_RDR)] (
untag_Expr tycon [(c_RDR, ch_RDR)] (
) tycon_loc))))
--------------------------------------------------------------
- single_con_ixes = single_con_range `AndMonoBinds`
- single_con_index `AndMonoBinds` single_con_inRange
+ single_con_ixes
+ = single_con_range `AndMonoBinds`
+ single_con_index `AndMonoBinds`
+ single_con_inRange
data_con
= case maybeTyConSingleCon tycon of -- just checking...
Nothing -> panic "get_Ix_binds"
- Just dc -> if (any isPrimType (dataConRawArgTys dc)) then
+ Just dc -> if (any isUnLiftedType (dataConRawArgTys dc)) then
error ("ERROR: Can't derive Ix for a single-constructor type with primitive argument types: "++tycon_str)
else
dc
- con_arity = argFieldCount data_con
+ con_arity = argFieldCount data_con
data_con_RDR = qual_orig_name data_con
- con_pat xs = ConPatIn data_con_RDR (map VarPatIn xs)
- con_expr xs = mk_easy_App data_con_RDR xs
as_needed = take con_arity as_RDRs
bs_needed = take con_arity bs_RDRs
cs_needed = take con_arity cs_RDRs
+ con_pat xs = ConPatIn data_con_RDR (map VarPatIn xs)
+ con_expr = mk_easy_App data_con_RDR cs_needed
+
--------------------------------------------------------------
single_con_range
- = mk_easy_FunMonoBind tycon_loc range_RDR [TuplePatIn [con_pat as_needed, con_pat bs_needed]] [] $
+ = mk_easy_FunMonoBind tycon_loc range_RDR
+ [TuplePatIn [con_pat as_needed, con_pat bs_needed] True{-boxed-}] [] $
HsDo ListComp stmts tycon_loc
where
stmts = zipWith3Equal "single_con_range" mk_qual as_needed bs_needed cs_needed
++
- [ReturnStmt (con_expr cs_needed)]
+ [ReturnStmt con_expr]
mk_qual a b c = BindStmt (VarPatIn c)
- (HsApp (HsVar range_RDR) (ExplicitTuple [HsVar a, HsVar b]))
+ (HsApp (HsVar range_RDR)
+ (ExplicitTuple [HsVar a, HsVar b] True))
tycon_loc
----------------
single_con_index
- = mk_easy_FunMonoBind tycon_loc index_RDR [TuplePatIn [con_pat as_needed, con_pat bs_needed], con_pat cs_needed] [range_size] (
+ = mk_easy_FunMonoBind tycon_loc index_RDR
+ [TuplePatIn [con_pat as_needed, con_pat bs_needed] True,
+ con_pat cs_needed] [range_size] (
foldl mk_index (HsLit (HsInt 0)) (zip3 as_needed bs_needed cs_needed))
where
mk_index multiply_by (l, u, i)
= genOpApp (
- (HsApp (HsApp (HsVar index_RDR) (ExplicitTuple [HsVar l, HsVar u])) (HsVar i))
+ (HsApp (HsApp (HsVar index_RDR)
+ (ExplicitTuple [HsVar l, HsVar u] True)) (HsVar i))
) plus_RDR (
genOpApp (
- (HsApp (HsVar rangeSize_RDR) (ExplicitTuple [HsVar l, HsVar u]))
+ (HsApp (HsVar rangeSize_RDR)
+ (ExplicitTuple [HsVar l, HsVar u] True))
) times_RDR multiply_by
)
range_size
- = mk_easy_FunMonoBind tycon_loc rangeSize_RDR [TuplePatIn [a_Pat, b_Pat]] [] (
+ = mk_easy_FunMonoBind tycon_loc rangeSize_RDR
+ [TuplePatIn [a_Pat, b_Pat] True] [] (
genOpApp (
- (HsApp (HsApp (HsVar index_RDR) (ExplicitTuple [a_Expr, b_Expr])) b_Expr)
+ (HsApp (HsApp (HsVar index_RDR)
+ (ExplicitTuple [a_Expr, b_Expr] True)) b_Expr)
) plus_RDR (HsLit (HsInt 1)))
------------------
single_con_inRange
= mk_easy_FunMonoBind tycon_loc inRange_RDR
- [TuplePatIn [con_pat as_needed, con_pat bs_needed], con_pat cs_needed]
+ [TuplePatIn [con_pat as_needed, con_pat bs_needed] True,
+ con_pat cs_needed]
[] (
foldl1 and_Expr (zipWith3Equal "single_con_inRange" in_range as_needed bs_needed cs_needed))
where
- in_range a b c = HsApp (HsApp (HsVar inRange_RDR) (ExplicitTuple [HsVar a, HsVar b])) (HsVar c)
+ in_range a b c = HsApp (HsApp (HsVar inRange_RDR)
+ (ExplicitTuple [HsVar a, HsVar b] True))
+ (HsVar c)
\end{code}
%************************************************************************
data_con_RDR = qual_orig_name data_con
data_con_str= occNameString (getOccName data_con)
con_arity = argFieldCount data_con
- as_needed = take con_arity as_RDRs
- bs_needed = take con_arity bs_RDRs
con_expr = mk_easy_App data_con_RDR as_needed
nullary_con = con_arity == 0
+ labels = dataConFieldLabels data_con
+ lab_fields = length labels
+ as_needed = take con_arity as_RDRs
+ bs_needed
+ | lab_fields == 0 = take con_arity bs_RDRs
+ | otherwise = take (4*lab_fields + 1) bs_RDRs
+ -- (label, '=' and field)*n, (n-1)*',' + '{' + '}'
con_qual
- = BindStmt
- (TuplePatIn [LitPatIn (HsString data_con_str), d_Pat])
- (HsApp (HsVar lex_RDR) c_Expr)
- tycon_loc
-
- field_quals = snd (mapAccumL mk_qual d_Expr (zipEqual "as_needed" as_needed bs_needed))
- mk_qual draw_from (con_field, str_left)
+ = BindStmt
+ (TuplePatIn [LitPatIn (HsString data_con_str),
+ d_Pat] True)
+ (HsApp (HsVar lex_RDR) c_Expr)
+ tycon_loc
+
+ str_qual str res draw_from
+ = BindStmt
+ (TuplePatIn [LitPatIn (HsString str), VarPatIn res] True)
+ (HsApp (HsVar lex_RDR) draw_from)
+ tycon_loc
+
+ read_label f
+ = let nm = occNameString (getOccName (fieldLabelName f))
+ in
+ [str_qual nm, str_qual SLIT("=")]
+ -- There might be spaces between the label and '='
+
+ field_quals
+ | lab_fields == 0 =
+ snd (mapAccumL mk_qual
+ d_Expr
+ (zipWithEqual "as_needed"
+ (\ con_field draw_from -> (mk_read_qual con_field,
+ draw_from))
+ as_needed bs_needed))
+ | otherwise =
+ snd $
+ mapAccumL mk_qual d_Expr
+ (zipEqual "bs_needed"
+ ((str_qual (SLIT("{")):
+ concat (
+ intersperse ([str_qual (_CONS_ ',' _NIL_)]) $
+ zipWithEqual
+ "field_quals"
+ (\ as b -> as ++ [b])
+ -- The labels
+ (map read_label labels)
+ -- The fields
+ (map mk_read_qual as_needed))) ++ [str_qual (SLIT("}"))])
+ bs_needed)
+
+ mk_qual draw_from (f, str_left)
= (HsVar str_left, -- what to draw from down the line...
- BindStmt
- (TuplePatIn [VarPatIn con_field, VarPatIn str_left])
- (HsApp (HsApp (HsVar readsPrec_RDR) (HsLit (HsInt 10))) draw_from)
- tycon_loc
- )
+ f str_left draw_from)
+
+ mk_read_qual con_field res draw_from =
+ BindStmt
+ (TuplePatIn [VarPatIn con_field, VarPatIn res] True)
+ (HsApp (HsApp (HsVar readsPrec_RDR) (HsLit (HsInt 10))) draw_from)
+ tycon_loc
result_expr = ExplicitTuple [con_expr, if null bs_needed
then d_Expr
- else HsVar (last bs_needed)]
+ else HsVar (last bs_needed)] True
- stmts = (con_qual : field_quals) ++ [ReturnStmt result_expr]
+ stmts = con_qual:field_quals ++ [ReturnStmt result_expr]
-
read_paren_arg
= if nullary_con then -- must be False (parens are surely optional)
false_Expr
HsLam (mk_easy_Match tycon_loc [c_Pat] [] $
HsDo ListComp stmts tycon_loc)
) (HsVar b_RDR)
+
\end{code}
%************************************************************************
pats_etc data_con
= let
data_con_RDR = qual_orig_name data_con
- con_arity = argFieldCount data_con
- bs_needed = take con_arity bs_RDRs
- con_pat = ConPatIn data_con_RDR (map VarPatIn bs_needed)
- nullary_con = con_arity == 0
+ con_arity = argFieldCount data_con
+ bs_needed = take con_arity bs_RDRs
+ con_pat = ConPatIn data_con_RDR (map VarPatIn bs_needed)
+ nullary_con = con_arity == 0
+ labels = dataConFieldLabels data_con
+ lab_fields = length labels
show_con
= let nm = occNameString (getOccName data_con)
- space_maybe = if nullary_con then _NIL_ else SLIT(" ")
+ space_ocurly_maybe
+ | nullary_con = _NIL_
+ | lab_fields == 0 = SLIT(" ")
+ | otherwise = SLIT("{")
+
+ in
+ mk_showString_app (nm _APPEND_ space_ocurly_maybe)
+
+ show_all con fs
+ = let
+ ccurly_maybe
+ | lab_fields > 0 = [mk_showString_app (SLIT("}"))]
+ | otherwise = []
in
- HsApp (HsVar showString_RDR) (HsLit (HsString (nm _APPEND_ space_maybe)))
+ con:fs ++ ccurly_maybe
- show_thingies = show_con : (spacified real_show_thingies)
+ show_thingies = show_all show_con real_show_thingies_with_labs
+
+ show_label l
+ = let nm = occNameString (getOccName (fieldLabelName l))
+ in
+ mk_showString_app (nm _APPEND_ SLIT("="))
+
+ mk_showString_app str = HsApp (HsVar showString_RDR)
+ (HsLit (HsString str))
+
+ real_show_thingies =
+ [ HsApp (HsApp (HsVar showsPrec_RDR) (HsLit (HsInt 10))) (HsVar b)
+ | b <- bs_needed ]
+
+ real_show_thingies_with_labs
+ | lab_fields == 0 = intersperse (HsVar showSpace_RDR) real_show_thingies
+ | otherwise = --Assumption: no of fields == no of labelled fields
+ -- (and in same order)
+ concat $
+ intersperse ([mk_showString_app (_CONS_ ',' _NIL_)]) $ -- Using SLIT()s containing ,s spells trouble.
+ zipWithEqual "gen_Show_binds"
+ (\ a b -> [a,b])
+ (map show_label labels)
+ real_show_thingies
+
- real_show_thingies
- = [ HsApp (HsApp (HsVar showsPrec_RDR) (HsLit (HsInt 10))) (HsVar b)
- | b <- bs_needed ]
in
if nullary_con then -- skip the showParen junk...
ASSERT(null bs_needed)
([a_Pat, con_pat],
showParen_Expr (HsPar (genOpApp a_Expr ge_RDR (HsLit (HsInt 10))))
(HsPar (nested_compose_Expr show_thingies)))
- where
- spacified [] = []
- spacified [x] = [x]
- spacified (x:xs) = (x : (HsVar showSpace_RDR) : spacified xs)
\end{code}
%************************************************************************
mk_stuff :: DataCon -> ([RdrNamePat], RdrNameHsExpr)
mk_stuff var
- = ASSERT(isDataCon var)
- ([pat], HsLit (HsIntPrim (toInteger ((dataConTag var) - fIRST_TAG))))
+ = ([pat], HsLit (HsIntPrim (toInteger ((dataConTag var) - fIRST_TAG))))
where
pat = ConPatIn var_RDR (nOfThem (argFieldCount var) WildPatIn)
var_RDR = qual_orig_name var
[([WildPatIn], impossible_Expr)])
where
mk_stuff :: DataCon -> ([RdrNamePat], RdrNameHsExpr)
-
- mk_stuff var
- = ASSERT(isDataCon var)
- ([lit_pat], HsVar var_RDR)
+ mk_stuff var = ([lit_pat], HsVar var_RDR)
where
lit_pat = ConPatIn mkInt_RDR [LitPatIn (HsIntPrim (toInteger ((dataConTag var) - fIRST_TAG)))]
var_RDR = qual_orig_name var
= mk_match loc pats expr (mkbind binds)
where
mkbind [] = EmptyBinds
- mkbind bs = MonoBind (foldr1 AndMonoBinds bs) [] recursive
+ mkbind bs = MonoBind (foldr1 AndMonoBinds bs) [] Recursive
-- The renamer expects everything in its input to be a
-- "recursive" MonoBinds, and it is its job to sort things out
-- from there.
mk_match loc pats expr binds
= foldr PatMatch
- (GRHSMatch (GRHSsAndBindsIn [OtherwiseGRHS expr loc] binds))
+ (GRHSMatch (GRHSsAndBindsIn (unguardedRHS expr loc) binds))
(map paren pats)
where
paren p@(VarPatIn _) = p
compare_gen_Case fun lt eq gt a b
= HsCase (HsPar (HsApp (HsApp (HsVar fun) a) b)) {-of-}
[PatMatch (ConPatIn ltTag_RDR [])
- (GRHSMatch (GRHSsAndBindsIn [OtherwiseGRHS lt mkGeneratedSrcLoc] EmptyBinds)),
+ (GRHSMatch (GRHSsAndBindsIn (unguardedRHS lt mkGeneratedSrcLoc) EmptyBinds)),
PatMatch (ConPatIn eqTag_RDR [])
- (GRHSMatch (GRHSsAndBindsIn [OtherwiseGRHS eq mkGeneratedSrcLoc] EmptyBinds)),
+ (GRHSMatch (GRHSsAndBindsIn (unguardedRHS eq mkGeneratedSrcLoc) EmptyBinds)),
PatMatch (ConPatIn gtTag_RDR [])
- (GRHSMatch (GRHSsAndBindsIn [OtherwiseGRHS gt mkGeneratedSrcLoc] EmptyBinds))]
+ (GRHSMatch (GRHSsAndBindsIn (unguardedRHS gt mkGeneratedSrcLoc) EmptyBinds))]
mkGeneratedSrcLoc
careful_compare_Case ty lt eq gt a b
- = if not (isPrimType ty) then
+ = if not (isUnboxedType ty) then
compare_gen_Case compare_RDR lt eq gt a b
else -- we have to do something special for primitive things...
= if null res then panic "assoc_ty"
else head res
where
- res = [id | (ty',id) <- tyids, eqTy ty ty']
+ res = [id | (ty',id) <- tyids, ty == ty']
eq_op_tbl =
[(charPrimTy, eqH_Char_RDR)
eq_Expr :: Type -> RdrNameHsExpr -> RdrNameHsExpr -> RdrNameHsExpr
eq_Expr ty a b
- = if not (isPrimType ty) then
+ = if not (isUnboxedType ty) then
genOpApp a eq_RDR b
else -- we have to do something special for primitive things...
genOpApp a relevant_eq_op b
\end{code}
\begin{code}
-argFieldCount :: Id -> Int -- Works on data and newtype constructors
+argFieldCount :: DataCon -> Int -- Works on data and newtype constructors
argFieldCount con = length (dataConRawArgTys con)
\end{code}
(GRHSMatch (GRHSsAndBindsIn grhs EmptyBinds))]
mkGeneratedSrcLoc
where
- grhs = [OtherwiseGRHS (untag_Expr tycon more expr) mkGeneratedSrcLoc]
+ grhs = unguardedRHS (untag_Expr tycon more expr) mkGeneratedSrcLoc
cmp_tags_Expr :: RdrName -- Comparison op
-> RdrName -> RdrName -- Things to compare