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|
module Standard ( generate )
where
import Atom
import Haskell
import Grammar hiding ( prec )
import qualified Grammar as G
import Convert
import LR0 hiding ( fromList )
import Lookahead
import Case
import qualified OrdUniqListSet as Set
import qualified SearchTree as ST
import Options
import Base
import Generate
import Char
import IO
import Maybe
import Prelude hiding ( lookup )
{-
ntArgsOf v ctx = args (pattern v)
where
args (Case e [(p, e')]) = Case e [(p, args e')]
args e = ctx (map fst (quotesOf e))
-}
generate :: [Flag] -> [(Symbol, State)] -> GotoTable -> BranchTable -> IO [Decl]
generate opts entries edges table
= do verb "* Generating Haskell code ... (--code=standard)"
return decls
where
verb = verbose opts
decls = [ DataDecl stack_tcon (
(unCon empty_con, [])
: [ (unCon (con_s_s e), stack_tcon : typesOf v)
| e@(s, v, s') <- edges ]) ]
++ [ Empty
, DataDecl nonterminal_tcon
[ (unCon (ntName n), typesOf n) | (n, _) <- entries ] ]
++ concat [ Empty
: [ Sig [unVar (globalNTName n)]
([ x_tcon | not lexFlag ] <->> result_tcon <$> [Tuple (typesOf n)])
| sigFlag ]
++ [funbind (globalNTName n <$> [tr_var | not lexFlag])
(next_n s (empty_con) False <>>=>
Fun [ntName n <$> genVars n]
(hsReturn <$> [Tuple (genVars n)]))]
| (n, s) <- entries ]
++ concat [ [ Empty ]
-- , AComment ["state " ++ show (snumber s) ++ reportConflicts cases ++ " "] ]
++ [ Sig [unVar (parse_var s)]
([x_tcon, stack_tcon] <->> result_tcon <$> [nonterminal_tcon])
| sigFlag ]
--OLD Sig [unVar (parse_var s)] (Con "Monad" <$> [Var "m"] <=>>
--OLD ([x_tcon, stack_tcon] <->> Var "m" <$> [nonterminal_tcon]))
++ genParse_n s cases
| (s, cases) <- ST.toList table ]
++ (if backtrFlag then
[ Empty ]
++ [ Sig [unVar impossible_var]
([x_tcon] <->> result_tcon <$> [nonterminal_tcon])
| sigFlag ]
++ [ funbind (notpossible x_var) (
hsFail <$> [stringLiteral "\"The `impossible' happened.\""])]
else
[])
trFlag = Trace `elem` opts
lexFlag = Lexer `elem` opts
expFlag = Expected `elem` opts
backtrFlag = Backtrack `elem` opts
sigFlag = Signature False `elem` opts || Signature True `elem` opts
x_var = if lexFlag then t_var else ts_var
x_tcon = if lexFlag then terminal_tcon else List [terminal_tcon]
genParse_n s (ReduceN as)
= reduces as Nothing ++ [ impossibleCase s | backtrFlag ]
genParse_n s (TokenCase es bs la)
= concat [ topLevel s e (Just t) | (t, e) <- es ]
++ catchall s bs la
genParse_n _ _ = impossible "Standard.genParse_n"
topLevel _s (Shift1 e) _ = [shift e False]
topLevel _s (ReduceN rs) t= reduces rs t
topLevel _s (ShiftReduce e b) _
= [shift e backtrFlag <||> caseexpr b]
topLevel s b t = [funbind (parse_n s st_var (genAnoPat t)) (caseexpr b)]
caseexpr (Shift1 e) = shiftRHS e -- this must be an error-correcting transition
caseexpr (ReduceN rs) = switch st_var ([ (genStack (stack r), reduceRHS r) | r <- rs ]
++ [ (anon, notpossible x_var) | backtrFlag ])
caseexpr (ReduceReduce rs)= foldr1 (<|>) [ switch st_var ([ (genStack (stack r), reduceRHS r)]
++ [(anon, frown (Set.empty))]) | r <- rs ] -- TODO: pass set of expected tokens
caseexpr (TokenCase es bs la) -- does not work with a monadic lexer
= switch tr_var ([ ( genNewPat x False, caseexpr t)
| (x, t) <- es ]
++ [(anon, catchallRHS bs la)])
caseexpr _ = impossible "Standard.caseexpr"
shift e@(s, t, _) flag = funbind (parse_n s st_var (genNewPat t flag)) (shiftRHS e)
shiftRHS e@(s, t, s') = trace
(hsPutStrLn <$>
[stringLiteral ("\"shift " ++ smangle s ++ " (\"")
<++> hsShow <$> [fresh t]
<++> stringLiteral ("\") " ++ smangle s' ++ "\"")])
(next_n s' (con_s_s e <$> (st_var : genVars t)) (modifier t == Insert))
next_n s st errCorr
| errCorr = parse_n s st x_var
| lexFlag = hsGet <>>=> Fun [t'_var] (parse_n s st t'_var)
| otherwise = parse_n s st tr_var
genNewPat v flag
| lexFlag = asPat' t_var (fresh v)
| isNewEOF (pattern v)= asPat' ts_var (asPat tr_var hsNil)
| otherwise = asPat' ts_var (fresh v <:> tr_var)
where asPat' x p
| flag = asPat x p
| otherwise = p
reduces rs x = [ reduce r x | r <- rs ]
reduce r x = funbind (parse_n (current r) (genStack (stack r)) (genAnoPat x))
(reduceRHS r)
reduceRHS (Reduce _st e@(_s, v, s') _ _ i)
| isStart v = trace
(hsPutStrLn <$> [stringLiteral "\"accept\""])
(evaluate (argsOf v) (\ args -> hsReturn <$> [ntName v <$> args]))
| otherwise = trace traceReduce
(evaluate (argsOf v) (\ args ->
proceed_n s' (con_s_s e <$> (st_var : args))))
where
traceReduce = hsPutStrLn <$> [stringLiteral ("\"reduce by " ++ show i ++ "\"")]
proceed_n s st' = parse_n s st' x_var
reduceRHS _ = impossible "Standard.reduceRHS"
genAnoPat Nothing = x_var
genAnoPat (Just v)
| lexFlag = asPat t_var (anonymous v)
| isNewEOF (pattern v)= asPat ts_var (asPat tr_var hsNil)
| otherwise = asPat ts_var (anonymous v <:> tr_var)
genStack Nil = st_var
genStack (st :> e@(_, v, _))
= con_s_s e <$> (genStack st : argsOf v)
trace tr e
| trFlag = tr <>>> e
| otherwise = e
catchall s bs la = [ funbind (parse_n s st_var x_var) (catchallRHS bs la) ]
catchallRHS bs la = if null bs then frown la else foldr1 (<|>) (map caseexpr bs)
impossibleCase s = funbind (parse_n s st_var x_var) (notpossible x_var)
frown la
| expFlag = hsFrown <$> [expected la, x_var]
| otherwise = hsFrown <$> [x_var]
FunBind lhs rhs <||> alt = FunBind lhs (rhs <|> alt)
_ <||> _ = impossible "Standard.<||>"
e1 <|> e2
| backtrFlag = Infix e1 (ident "`mplus`") e2
| otherwise = e1
parse_n i st ts = parse_var i <$> [ts, st]
notpossible ts = impossible_var <$> [ts]
parse_var i = wrap_var ("parse_" ++ smangle i)
impossible_var = wrap_var "impossible"
stack_tcon = wrap_con "Stack"
empty_con = wrap_con "Empty"
nonterminal_tcon = wrap_con "Nonterminal"
st_var = wrap_var "st"
ts_var = wrap_var "ts"
tr_var = wrap_var "tr"
t_var = wrap_var "t"
t'_var = wrap_var "t'"
con_s_s (s, _v, s') = wrap_con ("T_" ++ smangle s ++ "_" ++ smangle s')
globalNTName v = var (string (name v))
ntName v = wrap_con (string (name v))
wrap s = prefix opts ++ s ++ suffix opts
wrap_var s = var (wrap s)
wrap_con s = con (wrap s)
|
