Commit 276f03b2 authored by sof's avatar sof
Browse files

[project @ 1999-07-05 17:06:21 by sof]

Tidied up the handling of the code that emits the precedence level
predicates that gets used in applications of showParen and readParen.
parent ee731a02
......@@ -34,7 +34,9 @@ import HsSyn ( InPat(..), HsExpr(..), MonoBinds(..),
import RdrHsSyn ( mkOpApp, RdrNameMonoBinds, RdrNameHsExpr, RdrNamePat )
import RdrName ( RdrName, mkSrcUnqual )
import RnMonad ( Fixities )
import BasicTypes ( RecFlag(..), Fixity(..), FixityDirection(..) )
import BasicTypes ( RecFlag(..), Fixity(..), FixityDirection(..)
, maxPrecedence, defaultFixity
)
import FieldLabel ( fieldLabelName )
import DataCon ( isNullaryDataCon, dataConTag,
dataConRawArgTys, fIRST_TAG,
......@@ -57,7 +59,7 @@ import TysPrim ( charPrimTy, intPrimTy, wordPrimTy, addrPrimTy,
floatPrimTy, doublePrimTy
)
import Util ( mapAccumL, zipEqual, zipWithEqual,
zipWith3Equal, nOfThem )
zipWith3Equal, nOfThem, assocDefault )
import Panic ( panic, assertPanic )
import Maybes ( maybeToBool, assocMaybe )
import Constants
......@@ -897,7 +899,7 @@ gen_Read_binds fixities tycon
then d_Expr
else HsVar (last bs_needed)] True
[lp,rp] = getLRPrecs fixities dc_nm
[lp,rp] = getLRPrecs is_infix fixities dc_nm
quals
| is_infix = let (h:t) = field_quals in (h:con_qual:t)
......@@ -905,8 +907,11 @@ gen_Read_binds fixities tycon
stmts = quals ++ [ReturnStmt result_expr]
{-
c.f. Figure 18 in Haskell 1.1 report.
-}
paren_prec_limit
| not is_infix = 9
| not is_infix = fromInt maxPrecedence
| otherwise = getFixity fixities dc_nm
read_paren_arg -- parens depend on precedence...
......@@ -939,7 +944,7 @@ gen_Show_binds fixs_assoc tycon
([wildPat, con_pat], show_con)
| otherwise =
([a_Pat, con_pat],
showParen_Expr (HsPar (genOpApp a_Expr gt_RDR (HsLit (HsInt paren_prec_limit))))
showParen_Expr (HsPar (genOpApp a_Expr ge_RDR (HsLit (HsInt paren_prec_limit))))
(HsPar (nested_compose_Expr show_thingies)))
where
data_con_RDR = qual_orig_name data_con
......@@ -994,7 +999,7 @@ gen_Show_binds fixs_assoc tycon
mk_showString_app str = HsApp (HsVar showString_RDR)
(HsLit (mkHsString str))
prec_cons = getLRPrecs fixs_assoc dc_nm
prec_cons = getLRPrecs is_infix fixs_assoc dc_nm
real_show_thingies
| is_infix =
......@@ -1017,41 +1022,51 @@ gen_Show_binds fixs_assoc tycon
(con_left_assoc, con_right_assoc) = isLRAssoc fixs_assoc dc_nm
{-
c.f. Figure 16 and 17 in Haskell 1.1 report
-}
paren_prec_limit
| not is_infix = 9
| otherwise = getFixity fixs_assoc dc_nm
| not is_infix = fromInt maxPrecedence + 1
| otherwise = getFixity fixs_assoc dc_nm + 1
\end{code}
\begin{code}
getLRPrecs :: Fixities -> Name -> [Integer]
getLRPrecs fixs_assoc nm = [lp, rp]
getLRPrecs :: Bool -> Fixities -> Name -> [Integer]
getLRPrecs is_infix fixs_assoc nm = [lp, rp]
where
( con_left_assoc, con_right_assoc) = isLRAssoc fixs_assoc nm
paren_prec_limit = 9
{-
Figuring out the fixities of the arguments to a constructor,
cf. Figures 16-18 in Haskell 1.1 report.
-}
(con_left_assoc, con_right_assoc) = isLRAssoc fixs_assoc nm
paren_con_prec = getFixity fixs_assoc nm
maxPrec = fromInt maxPrecedence
lp
| con_left_assoc = paren_prec_limit
| otherwise = paren_prec_limit + 1
| not is_infix = maxPrec + 1
| con_left_assoc = paren_con_prec
| otherwise = paren_con_prec + 1
rp
| con_right_assoc = paren_prec_limit
| otherwise = paren_prec_limit + 1
| not is_infix = maxPrec + 1
| con_right_assoc = paren_con_prec
| otherwise = paren_con_prec + 1
getFixity :: Fixities -> Name -> Integer
getFixity fixs_assoc nm =
case assocMaybe fixs_assoc nm of
Nothing -> 9
Just (Fixity x _) -> fromInt x + 1
case lookupFixity fixs_assoc nm of
Fixity x _ -> fromInt x
isLRAssoc :: Fixities -> Name -> (Bool, Bool)
isLRAssoc fixs_assoc nm =
case assocMaybe fixs_assoc nm of
Just (Fixity _ InfixL) -> (True, False)
Just (Fixity _ InfixR) -> (False, True)
Just (Fixity _ _) -> (False, False)
_ -> (True, False)
case lookupFixity fixs_assoc nm of
Fixity _ InfixN -> (False, False)
Fixity _ InfixR -> (False, True)
Fixity _ InfixL -> (True, False)
lookupFixity :: Fixities -> Name -> Fixity
lookupFixity fixs_assoc nm = assocDefault defaultFixity fixs_assoc nm
\end{code}
......
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