hourglass-0.2.3: Data/Hourglass/Format.hs
-- |
-- Module : Data.Hourglass.Format
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : unknown
--
-- Time formatting : printing and parsing
--
-- Built-in format strings
--
{-# LANGUAGE FlexibleInstances #-}
module Data.Hourglass.Format
(
-- * Parsing and Printing
-- ** Format strings
TimeFormatElem(..)
, TimeFormatFct(..)
, TimeFormatString(..)
, TimeFormat(..)
-- ** Common built-in formats
, ISO8601_Date(..)
, ISO8601_DateAndTime(..)
-- ** Format methods
, timePrint
, timeParse
, timeParseE
, localTimePrint
, localTimeParse
, localTimeParseE
) where
import Data.Hourglass.Types
import Data.Hourglass.Time
import Data.Hourglass.Calendar
import Data.Hourglass.Local
import Data.Hourglass.Utils
import Data.Char (isDigit)
-- | All the various formatter that can be part
-- of a time format string
data TimeFormatElem =
Format_Year2 -- ^ 2 digit years (70 is 1970, 69 is 2069)
| Format_Year4 -- ^ 4 digits years
| Format_Year -- ^ any digits years
| Format_Month -- ^ months (1 to 12)
| Format_Month2 -- ^ months padded to 2 chars (01 to 12)
| Format_MonthName_Short -- ^ name of the month short ('Jan', 'Feb' ..)
| Format_DayYear -- ^ day of the year (1 to 365, 366 for leap years)
| Format_Day -- ^ day of the month (1 to 31)
| Format_Day2 -- ^ day of the month (01 to 31)
| Format_Hour -- ^ hours (0 to 23)
| Format_Minute -- ^ minutes (0 to 59)
| Format_Second -- ^ seconds (0 to 59, 60 for leap seconds)
| Format_UnixSecond -- ^ number of seconds since 1 jan 1970. unix epoch.
| Format_MilliSecond -- ^ Milliseconds (000 to 999)
| Format_MicroSecond -- ^ MicroSeconds (000000 to 999999)
| Format_NanoSecond -- ^ NanoSeconds (000000000 to 999999999)
| Format_Precision Int -- ^ sub seconds display with a precision of N digits. with N between 1 and 9
| Format_TimezoneName -- ^ timezone name (e.g. GMT, PST). not implemented yet
-- | Format_TimezoneOffset -- ^ timeoffset offset (+02:00)
| Format_TzHM_Colon -- ^ timeoffset offset with colon (+02:00)
| Format_TzHM -- ^ timeoffset offset (+0200)
| Format_Tz_Offset -- ^ timeoffset in minutes
| Format_Spaces -- ^ one or many space-like chars
| Format_Text Char -- ^ a verbatim char
| Format_Fct TimeFormatFct
deriving (Show,Eq)
-- | A generic format function composed of a parser and a printer.
data TimeFormatFct = TimeFormatFct
{ timeFormatFctName :: String
, timeFormatParse :: DateTime -> String -> Either String (DateTime, String)
, timeFormatPrint :: DateTime -> String
}
instance Show TimeFormatFct where
show f = timeFormatFctName f
instance Eq TimeFormatFct where
t1 == t2 = timeFormatFctName t1 == timeFormatFctName t2
-- | A time format string, composed of list of 'TimeFormatElem'
newtype TimeFormatString = TimeFormatString [TimeFormatElem]
deriving (Show,Eq)
-- | A generic class for anything that can be considered a Time Format string.
class TimeFormat format where
toFormat :: format -> TimeFormatString
-- | ISO8601 Date format string.
--
-- e.g. 2014-04-05
data ISO8601_Date = ISO8601_Date
deriving (Show,Eq)
-- | ISO8601 Date and Time format string.
--
-- e.g. 2014-04-05T17:25:04+00:00
-- 2014-04-05T17:25:04Z
data ISO8601_DateAndTime = ISO8601_DateAndTime
deriving (Show,Eq)
instance TimeFormat [TimeFormatElem] where
toFormat = TimeFormatString
instance TimeFormat TimeFormatString where
toFormat = id
instance TimeFormat String where
toFormat = TimeFormatString . toFormatElem
where toFormatElem [] = []
toFormatElem ('Y':'Y':'Y':'Y':r) = Format_Year4 : toFormatElem r
toFormatElem ('Y':'Y':r) = Format_Year2 : toFormatElem r
toFormatElem ('M':'M':r) = Format_Month2 : toFormatElem r
toFormatElem ('M':'o':'n':r) = Format_MonthName_Short : toFormatElem r
toFormatElem ('M':'I':r) = Format_Minute : toFormatElem r
toFormatElem ('M':r) = Format_Month : toFormatElem r
toFormatElem ('D':'D':r) = Format_Day2 : toFormatElem r
toFormatElem ('H':r) = Format_Hour : toFormatElem r
toFormatElem ('S':r) = Format_Second : toFormatElem r
toFormatElem ('m':'s':r) = Format_MilliSecond : toFormatElem r
toFormatElem ('u':'s':r) = Format_MicroSecond : toFormatElem r
toFormatElem ('μ':r) = Format_MicroSecond : toFormatElem r
toFormatElem ('n':'s':r) = Format_NanoSecond : toFormatElem r
toFormatElem ('p':'1':r) = Format_Precision 1 : toFormatElem r
toFormatElem ('p':'2':r) = Format_Precision 2 : toFormatElem r
toFormatElem ('p':'3':r) = Format_Precision 3 : toFormatElem r
toFormatElem ('p':'4':r) = Format_Precision 4 : toFormatElem r
toFormatElem ('p':'5':r) = Format_Precision 5 : toFormatElem r
toFormatElem ('p':'6':r) = Format_Precision 6 : toFormatElem r
toFormatElem ('p':'7':r) = Format_Precision 7 : toFormatElem r
toFormatElem ('p':'8':r) = Format_Precision 8 : toFormatElem r
toFormatElem ('p':'9':r) = Format_Precision 9 : toFormatElem r
-----------------------------------------------------------
toFormatElem ('E':'P':'O':'C':'H':r) = Format_UnixSecond : toFormatElem r
-----------------------------------------------------------
toFormatElem ('T':'Z':'H':'M':r) = Format_TzHM : toFormatElem r
toFormatElem ('T':'Z':'H':':':'M':r) = Format_TzHM_Colon : toFormatElem r
toFormatElem ('T':'Z':'O':'F':'S':r) = Format_Tz_Offset : toFormatElem r
-----------------------------------------------------------
toFormatElem ('\\':c:r) = Format_Text c : toFormatElem r
toFormatElem (' ':r) = Format_Spaces : toFormatElem r
toFormatElem (c:r) = Format_Text c : toFormatElem r
instance TimeFormat ISO8601_Date where
toFormat _ = TimeFormatString [Format_Year,dash,Format_Month2,dash,Format_Day2]
where dash = Format_Text '-'
instance TimeFormat ISO8601_DateAndTime where
toFormat _ = TimeFormatString
[Format_Year,dash,Format_Month2,dash,Format_Day2 -- date
,Format_Text 'T'
,Format_Hour,colon,Format_Minute,colon,Format_Second -- time
,Format_TzHM_Colon -- timezone offset with colon +HH:MM
]
where dash = Format_Text '-'
colon = Format_Text ':'
printWith :: (TimeFormat format, Timeable t)
=> format
-> TimezoneOffset
-> t
-> String
printWith fmt tzOfs@(TimezoneOffset tz) t = concatMap fmtToString fmtElems
where fmtToString Format_Year = show (dateYear date)
fmtToString Format_Year4 = pad4 (dateYear date)
fmtToString Format_Year2 = pad2 (dateYear date-1900)
fmtToString Format_Month2 = pad2 (fromEnum (dateMonth date)+1)
fmtToString Format_Month = show (fromEnum (dateMonth date)+1)
fmtToString Format_MonthName_Short = take 3 $ show (dateMonth date)
fmtToString Format_Day2 = pad2 (dateDay date)
fmtToString Format_Day = show (dateDay date)
fmtToString Format_Hour = pad2 (fromIntegral (todHour tm) :: Int)
fmtToString Format_Minute = pad2 (fromIntegral (todMin tm) :: Int)
fmtToString Format_Second = pad2 (fromIntegral (todSec tm) :: Int)
fmtToString Format_MilliSecond = padN 3 (ns `div` 1000000)
fmtToString Format_MicroSecond = padN 3 ((ns `div` 1000) `mod` 1000)
fmtToString Format_NanoSecond = padN 3 (ns `mod` 1000)
fmtToString (Format_Precision n)
| n >= 1 && n <= 9 = padN n (ns `div` (10 ^ (9 - n)))
| otherwise = error "invalid precision format"
fmtToString Format_UnixSecond = show unixSecs
fmtToString Format_TimezoneName = "" --
fmtToString Format_Tz_Offset = show tz
fmtToString Format_TzHM = show tzOfs
fmtToString Format_TzHM_Colon =
let (tzH, tzM) = abs tz `divMod` 60
sign = if tz < 0 then "-" else "+"
in sign ++ pad2 tzH ++ ":" ++ pad2 tzM
fmtToString Format_Spaces = " "
fmtToString (Format_Text c) = [c]
fmtToString f = error ("implemented printing format: " ++ show f)
(TimeFormatString fmtElems) = toFormat fmt
(Elapsed (Seconds unixSecs)) = timeGetElapsed t
(DateTime date tm) = timeGetDateTimeOfDay t
(NanoSeconds ns) = timeGetNanoSeconds t
-- | Pretty print local time to a string.
--
-- The actual output is determined by the format used.
localTimePrint :: (TimeFormat format, Timeable t)
=> format -- ^ the format to use for printing
-> LocalTime t -- ^ the local time to print
-> String -- ^ the resulting local time string
localTimePrint fmt lt = localTimeUnwrap $ fmap (printWith fmt (localTimeGetTimezone lt)) lt
-- | Pretty print time to a string
--
-- The actual output is determined by the format used
timePrint :: (TimeFormat format, Timeable t)
=> format -- ^ the format to use for printing
-> t -- ^ the global time to print
-> String -- ^ the resulting string
timePrint fmt t = printWith fmt timezone_UTC t
-- | Try parsing a string as time using the format explicitely specified
--
-- On failure, the parsing function returns the reason of the failure.
-- If parsing is successful, return the date parsed with the remaining unparsed string
localTimeParseE :: TimeFormat format
=> format -- ^ the format to use for parsing
-> String -- ^ the string to parse
-> Either (TimeFormatElem, String) (LocalTime DateTime, String)
localTimeParseE fmt timeString = loop ini fmtElems timeString
where (TimeFormatString fmtElems) = toFormat fmt
toLocal (dt, tz) = localTime tz dt
loop acc [] s = Right (toLocal acc, s)
loop _ (x:_) [] = Left (x, "empty")
loop acc (x:xs) s =
case processOne acc x s of
Left err -> Left (x, err)
Right (nacc, s') -> loop nacc xs s'
processOne _ _ [] = Left "empty"
processOne acc (Format_Text c) (x:xs)
| c == x = Right (acc, xs)
| otherwise = Left ("unexpected char, got: " ++ show c)
processOne acc Format_Year s =
onSuccess (\y -> modDate (setYear y) acc) $ isNumber s
processOne acc Format_Year4 s =
onSuccess (\y -> modDate (setYear y) acc) $ is4Digit s
processOne acc Format_Year2 s = onSuccess
(\y -> let year = if y < 70 then y + 2000 else y + 1900 in modDate (setYear year) acc)
$ is2Digit s
processOne acc Format_Month2 s =
onSuccess (\m -> modDate (setMonth $ toEnum ((m - 1) `mod` 12)) acc) $ is2Digit s
processOne acc Format_Day2 s =
onSuccess (\d -> modDate (setDay d) acc) $ is2Digit s
processOne acc Format_Hour s =
onSuccess (\h -> modTime (setHour h) acc) $ is2Digit s
processOne acc Format_Minute s =
onSuccess (\mi -> modTime (setMin mi) acc) $ is2Digit s
processOne acc Format_Second s =
onSuccess (\sec -> modTime (setSec sec) acc) $ is2Digit s
processOne acc Format_MilliSecond s =
onSuccess (\ms -> modTime (setNsMask (6,3) ms) acc) $ isNDigit 3 s
processOne acc Format_MicroSecond s =
onSuccess (\us -> modTime (setNsMask (3,3) us) acc) $ isNDigit 3 s
processOne acc Format_NanoSecond s =
onSuccess (\ns -> modTime (setNsMask (0,3) ns) acc) $ isNDigit 3 s
processOne acc (Format_Precision p) s =
onSuccess (\num -> modTime (setNS num) acc) $ isNDigit p s
processOne acc Format_UnixSecond s =
onSuccess (\sec ->
let newDate = dateTimeFromUnixEpochP $ flip ElapsedP 0 $ Elapsed $ Seconds sec
in modDT (const newDate) acc) $ isNumber s
processOne acc Format_TzHM_Colon (c:s) =
parseHMSign True acc c s
processOne acc Format_TzHM (c:s) =
parseHMSign False acc c s
-- catch all for unimplemented format.
processOne _ f _ = error ("unimplemened parsing format: " ++ show f)
parseHMSign expectColon acc signChar afterSign =
case signChar of
'+' -> parseHM False expectColon afterSign acc
'-' -> parseHM True expectColon afterSign acc
_ -> parseHM False expectColon (signChar:afterSign) acc
parseHM isNeg True (h1:h2:':':m1:m2:xs) acc
| allDigits [h1,h2,m1,m2] = let tz = toTZ isNeg h1 h2 m1 m2
in Right (modTZ (const tz) acc, xs)
| otherwise = Left ("not digits chars: " ++ show [h1,h2,m1,m2])
parseHM isNeg False (h1:h2:m1:m2:xs) acc
| allDigits [h1,h2,m1,m2] = let tz = toTZ isNeg h1 h2 m1 m2
in Right (modTZ (const tz) acc, xs)
| otherwise = Left ("not digits chars: " ++ show [h1,h2,m1,m2])
parseHM _ _ _ _ = Left ("invalid timezone format")
toTZ isNeg h1 h2 m1 m2 = TimezoneOffset ((if isNeg then negate else id) minutes)
where minutes = (read [h1,h2] * 60) + read [m1,m2]
onSuccess f (Right (v, s')) = Right (f v, s')
onSuccess _ (Left s) = Left s
is4Digit (a:b:c:d:s)
| allDigits [a,b,c,d] = Right (read (a:b:c:d:[]), s)
| otherwise = Left ("not digits chars: " ++ show [a,b,c,d])
is4Digit _ = Left ("not enough chars")
is2Digit (a:b:s)
| isDigit a && isDigit b = Right (read (a:b:[]), s)
| otherwise = Left ("not digits chars: " ++ show [a,b])
is2Digit _ = Left ("not enough chars")
isNDigit n l
| length l1 < n = Left ("not enough chars")
| and $ map isDigit l1 = Right (read l1, l2)
| otherwise = Left ("not digits chars: " ++ show l)
where (l1, l2) = splitAt n l
isNumber :: (Read a, Num a) => String -> Either String (a, String)
isNumber s =
case span isDigit s of
("",s2) -> Left ("no digits chars:" ++ s2)
(s1,s2) -> Right (read s1, s2)
allDigits = and . map isDigit
ini = (DateTime (Date 0 (toEnum 0) 0) (TimeOfDay 0 0 0 0), TimezoneOffset 0)
modDT f (dt, tz) = (f dt, tz)
modDate f (DateTime d tp, tz) = (DateTime (f d) tp, tz)
modTime f (DateTime d tp, tz) = (DateTime d (f tp), tz)
modTZ f (dt, tz) = (dt, f tz)
setYear y (Date _ m d) = Date y m d
setMonth m (Date y _ d) = Date y m d
setDay d (Date y m _) = Date y m d
setHour h (TimeOfDay _ m s ns) = TimeOfDay h m s ns
setMin m (TimeOfDay h _ s ns) = TimeOfDay h m s ns
setSec s (TimeOfDay h m _ ns) = TimeOfDay h m s ns
setNS v (TimeOfDay h m s _ ) = TimeOfDay h m s v
setNsMask :: (Int, Int) -> Int -> TimeOfDay -> TimeOfDay
setNsMask (shift, mask) val (TimeOfDay h mins seconds (NanoSeconds ns)) =
let (nsD,keepL) = ns `divMod` s
(keepH,_) = nsD `divMod` m
v = ((keepH * m + fromIntegral val) * s) + keepL
in TimeOfDay h mins seconds (NanoSeconds v)
where s = 10 ^ shift
m = 10 ^ mask
-- | Try parsing a string as time using the format explicitely specified
--
-- Unparsed characters are ignored and the error handling is simplified
--
-- for more elaborate need use 'localTimeParseE'.
localTimeParse :: TimeFormat format
=> format -- ^ the format to use for parsing
-> String -- ^ the string to parse
-> Maybe (LocalTime DateTime)
localTimeParse fmt s = either (const Nothing) (Just . fst) $ localTimeParseE fmt s
-- | like 'localTimeParseE' but the time value is automatically converted to global time.
timeParseE :: TimeFormat format => format -> String
-> Either (TimeFormatElem, String) (DateTime, String)
timeParseE fmt timeString = either Left (\(d,s) -> Right (localTimeToGlobal d, s))
$ localTimeParseE fmt timeString
-- | Just like 'localTimeParse' but the time is automatically converted to global time.
timeParse :: TimeFormat format => format -> String -> Maybe DateTime
timeParse fmt s = localTimeToGlobal `fmap` localTimeParse fmt s