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implementation module SimpleParse
import StdList, StdTuple
from StdFunc import o
import Yard
import WhileCommon
import WhileLexer
import Simple
instance parse Stm
where
parse cs = fst (runParser parser cs)
where
parser :: Parser Token Stm
parser = liftM2 Compose parser` (item CompToken *> parser) <|> parser`
parser` :: Parser Token Stm
parser` = item ParenOpen *> parser <* item ParenClose
<|> item SkipToken *> pure Skip
<|> item IfToken *> liftM3 If
pbexpr
(item ThenToken *> parser)
(item ElseToken *> parser`)
<|> item WhileToken *> liftM2 While
pbexpr
(item DoToken *> parser`)
<|> liftM2 Ass
(toVar <$> satisfy isVarToken)
(item AssToken *> paexpr)
toVar (VarToken v) = v
isVarToken (VarToken _) = True; isVarToken _ = False
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