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|
module Compact ( 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 OrdUniqListSet ( Set )
import qualified SearchTree as ST
import Options
import Base
import Generate
import MergeSort
import Char
import IO
import Maybe
import Prelude hiding ( lookup )
back :: RevList Edge -> State
back Nil = impossible "Compact.back"
back (Nil :> (s, _ ,_)) = s
back (st :> _) = back st
{-
ntArgsOf v ctx = args (pattern v)
where
args (Case e [(p, e')]) = Case e [(p, args e')]
args e = ctx (map fst (quotesOf e))
-}
extract :: Branch -> [Action]
extract (Shift1 _e) = []
extract (ReduceN rs) = rs
extract (ShiftReduce _e b) = extract b
extract (ReduceReduce rs) = rs
extract (TokenCase es bs _la) = concat [ extract b | b <- map snd es ++ bs ]
reductions :: [Branch] -> [[(Int, Action)]]
reductions bs = groupBy equ1 (mergeSortBy leq1 rs)
where rs = [ (pnumber r, r) | b <- bs, r <- extract b ]
safeLookup :: (Show a, Ord a) => ST.FM a v -> a -> v
safeLookup fm a = fromMaybe (error ("not found: " ++ show a)) (ST.lookup fm a)
data Tree a = Node a [Tree a]
deriving (Eq, Ord, Show)
key :: Symbol -> Tree Int
key (Terminal { number = n}) = Node n []
key (Nonterminal { number = n, arguments = vs})
= Node n (map key vs)
generate :: [Flag] -> Grammar -> [(Symbol, State)]
-> Set Symbol -> GotoTable -> BranchTable -> IO [Decl]
generate opts grammar entries reachable edges table
= do verb "* Generating Haskell code ... (--code=compact)"
-- print (symbols grammar)
-- print reachable
let sgs = length [ n | (n, b) <- ST.toList singleGotoFM, b ]
verb (" " ++ show sgs ++ " singleton gotos (of "
++ show (ST.length singleGotoFM) ++ ")")
let sss = length [ s | (s, b) <- ST.toList shiftOnlyFM, b ]
verb (" " ++ show sss ++ " `stateless' states (of "
++ show (ST.length shiftOnlyFM) ++ ")")
return decls
where
verb = verbose opts
decls = [ DataDecl stack_tcon (
(unCon empty_con, [])
: [ (unCon (wrap_con ("T_" ++ s)), state_tcon : stack_tcon : ts)
| (ts, s) <- stTypes ]
++ if optimize then
[ (unCon (wrap_con ("T'_" ++ s)), stack_tcon : ts)
| (ts, s) <- stTypes ]
else
[]) ]
++ (if ghcFlag then
[]
else
let constrs = [ (unCon (s_con s), [])
| (s, _) <- ST.toList table
, not (stateless s) ]
in [ Empty
, DataDecl state_tcon (if null constrs then
[(unCon (wrap_con "Void"), [])]
else constrs) ])
++ [ Empty
, DataDecl nonterminal_tcon
[ (unCon (ntName n), typesOf n) | (n, _) <- entries ] ]
++ [ Empty ]
++ 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" ++ (if stateless s then "*" else "") ++ " " ++ show (snumber s) ++ reportConflicts cases ++ " "]
: genParse_n s cases
| (s, cases) <- ST.toList table ]
++ concat [ Empty
: [ funbind (reduce_var p <$>
([x_var] ++ [ s_var | epsilon && not (stateless (let (s, _, _) = goto r' in s)) ] ++ [genStack2 (stack r')]))
(reduceRHS' r')
| r' <- collapse (map snd prs) ]
++ if epsilon || not backtrFlag then
[]
else
funbind (reduce_var p <$>
([x_var, st_var]))
(notpossible st_var x_var) : []
| prs <- reductions (map snd (ST.toList table))
, let (p, r) = head prs, let epsilon = stack r == Nil ]
++ concat [ Empty
: [ funbind (goto_var v <$> [s_con s])
(parse_var s')
| e@(s, v', s') <- edges, v' == v ]
| v <- Set.toList reachable, not (singleGoto v) ]
++ [ Empty
, funbind (notpossible st_var x_var) (
hsFail <$> [stringLiteral "\"The `impossible' happened.\""])]
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
optimize = Optimize `elem` opts
symbolsByType = groupBy equ2 (mergeSortBy leq2 [ (v, typesOf v) | v <- symbols grammar ])
stTypes = zip (map (snd . head) symbolsByType) (map show [(1 :: Int) ..])
stFM = ST.fromList [ (key v, show i)
| (i, sx) <- zip [(1 :: Int) ..] symbolsByType, (v, _) <- sx ]
lookupStFM v = safeLookup stFM (key v)
shiftOnlyFM = ST.fromList [ (snumber s, and [ singleGoto v
| (s1, v, s2) <- edges
, s1 == s, nonterminal v ])
| (s, _) <- ST.toList table ]
stateless s = optimize && safeLookup shiftOnlyFM (snumber s)
singleGotoFM = ST.fromList [ (n, length [ e | e@(s, v, s') <- edges, v == n ] <= 1)
| n <- Set.toList reachable ]
singleGoto v = optimize && safeLookup singleGotoFM v
genParse_n _s (ReduceN as)
= reduces as Nothing
genParse_n s (TokenCase es bs la)
= concat [ topLevel s e (Just t) | (t, e) <- es ]
++ catchall s bs la
genParse_n _ _ = impossible "Compact.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)
| equal (map pnumber rs)= reduceRHS (head rs) True
| otherwise = switch st_var ([ (genStack1 (stack r), reduceRHS r False) | r <- rs ]
++ [ (anon, notpossible st_var x_var) | backtrFlag ])
caseexpr (ReduceReduce rs)= foldr1 (<|>) [ switch st_var ([ (genStack1 (stack r), reduceRHS r False)]
++ [(anon, frown (Set.empty))]) | r <- rs ] -- TODO: pass set of expected tokens
caseexpr (TokenCase es bs la)
= switch tr_var ([ ( genNewPat x False, caseexpr t)
| (x, t) <- es ]
++ [(anon, catchallRHS bs la)])
caseexpr _ = impossible "Compact.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
| equal (map pnumber rs)= [ reduce (head rs) x True ]
| otherwise = [ reduce r x False | r <- rs ]
reduce r x True = funbind (parse_n (current r) st_var (genAnoPat x))
(reduceRHS r True)
reduce r x False = funbind (parse_n (current r) (genStack1 (stack r)) (genAnoPat x))
(reduceRHS r False)
reduceRHS (Reduce st (s, _, _) _ _ i) True
= reduce_var i <$>
([x_var] ++ [ s_con s | st == Nil && not (stateless s) ] ++ [st_var])
reduceRHS (Reduce _ e@(_, v, s') _ _ i) False
| isStart v = trace
(hsPutStrLn <$> [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 <$> [stringLiteral ("\"reduce by " ++ show i ++ "\"")]
proceed_n s st' = parse_n s st' x_var
reduceRHS _ _ = impossible "Compact.reduceRHS"
reduceRHS' (Reduce _ (s, v, s') _ _ i)
| isStart v = trace
(hsPutStrLn <$> [stringLiteral "\"accept\""])
(evaluate (argsOf v) (\ args -> hsReturn <$> [ntName v <$> args]))
| otherwise = trace traceReduce
(evaluate (argsOf v) (\ args ->
proceed_n (x st_var args)))
where
traceReduce = hsPutStrLn <$> [stringLiteral ("\"reduce by " ++ show i ++ "\"")]
x st vs
| stateless s = if null vs then st else st_con v <$> (st : vs)
| otherwise = sts_con v <$> (s_var : st : vs)
proceed_n st'
| singleGoto v = parse_n s' st' x_var
| otherwise = goto_var v <$> [s_var, x_var, st']
reduceRHS' _ = impossible "Compact.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)
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)
frown la
| expFlag = hsFrown <$> [expected la, x_var]
| otherwise = hsFrown <$> [x_var]
x_var = if lexFlag then t_var else ts_var
x_tcon = if lexFlag then terminal_tcon else List [terminal_tcon]
genStack1 Nil = st_var
genStack1 (st :> e@(_, v, _))
= con_s_s e (genStack1 st) (argsOf v)
genStack2 Nil = st_var
genStack2 (st :> e@(s, v, _))
| stateless s = con_s_s e (genStack2 st) (argsOf v)
| otherwise = sts_con v <$> ((if st == Nil then s_var else anon): genStack2 st : argsOf v)
con_s_s (s, v, _s') st vs
| stateless s = if null vs then st else st_con v <$> (st : vs)
| otherwise = sts_con v <$> (s_con s : st : vs)
collapse rs = map (fst . head) gs
where char r = (r, [ stateless s | (s, _, _) <- list (stack r) ])
gs = groupBy equ2 (mergeSortBy leq2 (map char rs))
ghcFlag = GHC `elem` opts
state_tcon | ghcFlag = con "Int#"
| otherwise = wrap_con "State"
s_con s | ghcFlag = stringLiteral (smangle s ++ "#")
| otherwise = wrap_con ("S_" ++ smangle s)
FunBind lhs rhs <||> alt = FunBind lhs (rhs <|> alt)
_ <||> _ = impossible "Compact.<||>"
e1 <|> e2
| backtrFlag = Infix e1 (ident "`mplus`") e2
| otherwise = e1
sts_con v = wrap_con ("T_" ++ lookupStFM v)
st_con v = wrap_con ("T'_" ++ lookupStFM v)
parse_n i st ts = parse_var i <$> [ts, st]
notpossible st ts = impossible_var <$> [ts, st]
parse_var i = wrap_var ("parse_" ++ smangle i)
goto_var v = wrap_var ("goto_" ++ vmangle 1 v)
reduce_var i = wrap_var ("reduce_" ++ show 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'"
s_var = wrap_var "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)
|
