git.iko.soy/project-m36
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project-m36/TutorialD/Interpreter/DataTypes/Interval.hs
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1module TutorialD.Interpreter.DataTypes.Interval where
2import Text.Parsec
3import Text.Parsec.String
4import ProjectM36.Base
5import ProjectM36.DataTypes.Interval ()
6import TutorialD.Interpreter.Base
7import TutorialD.Interpreter.DataTypes.DateTime
8import Data.Interval
9import Data.Time.Clock
11intervalP :: (Ord a) => Parser (Extended a) -> Parser (Interval a)
12intervalP unitP = do
13 lBoundClosed <- string "(" *> return False <|>
14 string "[" *> return True
15 lBound <- unitP
16 reservedOp ","
17 uBound <- unitP
19 uBoundClosed <- string ")" *> return False <|>
20 string "]" *> return True
22 return $ interval (lBound, lBoundClosed) (uBound, uBoundClosed)
24intervalDateTimeUnitP :: Parser (Extended UTCTime)
25intervalDateTimeUnitP = Finite <$> dateTimeStringP <|>
26 (reserved "inf" *> return PosInf) <|>
27 (reserved "-inf" *> return NegInf)
29intervalDateTimeAtomP :: Parser Atom
30intervalDateTimeAtomP = do
31 reserved "interval_datetime("
32 intv <- intervalP intervalDateTimeUnitP
33 reserved ")"
34 return $ Atom intv