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forked from GitHub/gf-core
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gf-core/src/compiler/GF/Compile/GenerateBC.hs
2012-08-30 08:09:30 +00:00

76 lines
2.1 KiB
Haskell

module GF.Compile.GenerateBC(generateByteCode) where
import GF.Grammar
import GF.Compile.Instructions
import PGF.Data
import Data.Maybe
import qualified Data.IntMap as IntMap
import qualified Data.ByteString as BSS
import qualified Data.ByteString.Lazy as BS
import Data.Binary
generateByteCode :: [(QIdent,Info)] -> ([(QIdent,Info,BCAddr)], BSS.ByteString)
generateByteCode = runGenM . mapM genFun
type BCLabel = (Int, BCAddr)
genFun (id,info@(AbsFun (Just (L _ ty)) ma pty _)) = do
l1 <- newLabel
{- emitLabel l1
emit Ins_fail
l2 <- newLabel
l3 <- newLabel
emit (Ins_switch_on_reg (1,addr l2,addr l3))
emitLabel l2
emit (Ins_try (1,addr l3))
emit (Ins_trust_ext (1,1))
emit (Ins_try_me_else (0,addr l1))
emitLabel l3
l4 <- newLabel
l5 <- newLabel
emit (Ins_switch_on_term (addr l4,addr l5,addr l1,addr l4))
emitLabel l4
emitLabel l5-}
return (id,info,addr l1)
genFun (id,info@(AbsCat (Just (L _ cont)))) = do
l1 <- newLabel
return (id,info,addr l1)
newtype GenM a = GenM {unGenM :: IntMap.IntMap BCAddr ->
IntMap.IntMap BCAddr ->
[Instruction] ->
(a,IntMap.IntMap BCAddr,[Instruction])}
instance Monad GenM where
return x = GenM (\fm cm is -> (x,cm,is))
f >>= g = GenM (\fm cm is -> case unGenM f fm cm is of
(x,cm,is) -> unGenM (g x) fm cm is)
runGenM :: GenM a -> (a, BSS.ByteString)
runGenM f =
let (x, cm, is) = unGenM f cm IntMap.empty []
in (x, BSS.concat (BS.toChunks (encode (BC (reverse is)))))
emit :: Instruction -> GenM ()
emit i = GenM (\fm cm is -> ((), cm, i:is))
newLabel :: GenM BCLabel
newLabel = GenM (\fm cm is ->
let lbl = IntMap.size cm
addr = fromMaybe (error "newLabel") (IntMap.lookup lbl fm)
in ((lbl,addr), IntMap.insert lbl 0 cm, is))
emitLabel :: BCLabel -> GenM ()
emitLabel (lbl,addr) = GenM (\fm cm is ->
((), IntMap.insert lbl (length is) cm, is))
addr :: BCLabel -> BCAddr
addr (lbl,addr) = addr
data ByteCode = BC [Instruction]
instance Binary ByteCode where
put (BC is) = mapM_ putInstruction is
get = error "get ByteCode"