2 % (c) The GRASP/AQUA Project, Glasgow University, 1995-97
4 \section[Time]{Haskell 1.4 Time of Day Library}
6 The {\em Time} library provides standard functionality for
7 clock times, including timezone information (i.e, the functionality of
8 "time.h", adapted to the Haskell environment), It follows RFC 1129 in
9 its use of Coordinated Universal Time (UTC).
12 {-# OPTIONS -#include "cbits/timezone.h" -#include "cbits/stgio.h" #-}
18 CalendarTime(CalendarTime),
20 ClockTime(..), -- non-standard, lib. report gives this as abstract
37 import PrelUnsafe ( unsafePerformIO )
39 import PrelPack ( unpackCString )
42 import Char ( intToDigit )
47 One way to partition and give name to chunks of a year and a week:
51 = January | February | March | April
52 | May | June | July | August
53 | September | October | November | December
54 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
57 = Sunday | Monday | Tuesday | Wednesday
58 | Thursday | Friday | Saturday
59 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
63 @ClockTime@ is an abstract type, used for the internal clock time.
64 Clock times may be compared, converted to strings, or converted to an
65 external calendar time @CalendarTime@.
68 data ClockTime = TOD Integer Integer deriving (Eq, Ord)
71 When a @ClockTime@ is shown, it is converted to a string of the form
72 @"Mon Nov 28 21:45:41 GMT 1994"@.
74 For now, we are restricted to roughly:
75 Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
76 we use the C library routines based on 32 bit integers.
79 instance Show ClockTime where
80 showsPrec p (TOD sec@(J# a# s# d#) nsec) = showString $ unsafePerformIO $
81 allocChars 32 >>= \ buf ->
82 _ccall_ showTime (I# s#) (ByteArray bottom d#) buf
84 return (unpackCString str)
86 showList = showList__ (showsPrec 0)
90 @CalendarTime@ is a user-readable and manipulable
91 representation of the internal $ClockTime$ type. The
92 numeric fields have the following ranges.
98 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
99 mon 0 .. 11 [Jan = 0, Dec = 11]
103 sec 0 .. 61 [Allows for two leap seconds]
104 picosec 0 .. (10^12)-1 [This could be over-precise?]
105 wday 0 .. 6 [Sunday = 0, Saturday = 6]
106 yday 0 .. 365 [364 in non-Leap years]
107 tz -43200 .. 43200 [Variation from UTC in seconds]
110 The {\em tzname} field is the name of the time zone. The {\em isdst}
111 field indicates whether Daylight Savings Time would be in effect.
122 ctPicosec :: Integer,
129 deriving (Eq,Ord,Read,Show)
133 The @TimeDiff@ type records the difference between two clock times in
145 tdPicosec :: Integer -- not standard
147 deriving (Eq,Ord,Read,Show)
150 @getClockTime@ returns the current time in its internal representation.
153 getClockTime :: IO ClockTime
157 _ccall_ getClockTime i1 i2 >>= \ rc ->
160 cvtUnsigned i1 >>= \ sec ->
161 cvtUnsigned i2 >>= \ nsec ->
162 return (TOD sec (nsec * 1000))
164 constructErrorAndFail "getClockTime"
166 malloc1 = IO $ \ s# ->
167 case newIntArray# 1# s# of
168 StateAndMutableByteArray# s2# barr# ->
169 IOok s2# (MutableByteArray bottom barr#)
171 -- The C routine fills in an unsigned word. We don't have
172 -- `unsigned2Integer#,' so we freeze the data bits and use them
173 -- for an MP_INT structure. Note that zero is still handled specially,
174 -- although (J# 1# 1# (ptr to 0#)) is probably acceptable to gmp.
176 cvtUnsigned (MutableByteArray _ arr#) = IO $ \ s# ->
177 case readIntArray# arr# 0# s# of
178 StateAndInt# s2# r# ->
181 else case unsafeFreezeByteArray# arr# s2# of
182 StateAndByteArray# s3# frozen# ->
183 IOok s3# (J# 1# 1# frozen#)
187 @addToClockTime@ {\em d} {\em t} adds a time difference {\em d} and a
188 clock time {\em t} to yield a new clock time. The difference {\em d}
189 may be either positive or negative. @[diffClockTimes@ {\em t1} {\em
190 t2} returns the difference between two clock times {\em t1} and {\em
195 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
196 addToClockTime (TimeDiff year mon day hour min sec psec)
197 (TOD c_sec c_psec) = unsafePerformIO $
198 allocWords (``sizeof(time_t)'') >>= \ res ->
199 _ccall_ toClockSec year mon day hour min sec 0 res
200 >>= \ ptr@(A# ptr#) ->
203 diff_sec = (int2Integer# (indexIntOffAddr# ptr# 0#))
206 return (TOD (c_sec + diff_sec) (c_psec + diff_psec))
208 error "Time.addToClockTime: can't perform conversion of TimeDiff"
211 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
212 diffClockTimes tod_a tod_b =
214 CalendarTime year_a mon_a day_a hour_a min_a sec_a psec_a _ _ _ _ _ = toCalendarTime tod_a
215 CalendarTime year_b mon_b day_b hour_b min_b sec_b psec_b _ _ _ _ _ = toCalendarTime tod_b
217 TimeDiff (year_a - year_b)
226 @toCalendarTime@ {\em t} converts {\em t} to a local time, modified by
227 the current timezone and daylight savings time settings. @toUTCTime@
228 {\em t} converts {\em t} into UTC time. @toClockTime@ {\em l}
229 converts {\em l} into the corresponding internal @ClockTime@. The
230 {\em wday}, {\em yday}, {\em tzname}, and {\em isdst} fields are
234 toCalendarTime :: ClockTime -> CalendarTime
235 toCalendarTime (TOD sec@(J# a# s# d#) psec) = unsafePerformIO $
236 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
237 allocChars 32 >>= \ zoneNm ->
238 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
239 _ccall_ toLocalTime (I# s#) (ByteArray bottom d#) res
241 if tm == (``NULL''::Addr)
242 then error "Time.toCalendarTime: out of range"
244 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
245 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
246 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
247 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
248 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
249 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
250 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
251 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
252 _casm_ ``%r = ((struct tm *)%0)->tm_isdst;'' tm >>= \ isdst ->
253 _ccall_ ZONE tm >>= \ zone ->
254 _ccall_ GMTOFF tm >>= \ tz ->
256 tzname = unpackCString zone
258 return (CalendarTime (1900+year) mon mday hour min sec psec
259 (toEnum wday) yday tzname tz (isdst /= 0))
261 toUTCTime :: ClockTime -> CalendarTime
262 toUTCTime (TOD sec@(J# a# s# d#) psec) = unsafePerformIO (
263 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
264 allocChars 32 >>= \ zoneNm ->
265 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
266 _ccall_ toUTCTime (I# s#) (ByteArray bottom d#) res
268 if tm == (``NULL''::Addr)
269 then error "Time.toUTCTime: out of range"
271 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
272 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
273 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
274 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
275 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
276 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
277 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
278 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
279 return (CalendarTime (1900+year) mon mday hour min sec psec
280 (toEnum wday) yday "UTC" 0 False)
283 toClockTime :: CalendarTime -> ClockTime
284 toClockTime (CalendarTime year mon mday hour min sec psec wday yday tzname tz isdst) =
285 if psec < 0 || psec > 999999999999 then
286 error "Time.toClockTime: picoseconds out of range"
287 else if tz < -43200 || tz > 43200 then
288 error "Time.toClockTime: timezone offset out of range"
291 allocWords (``sizeof(time_t)'') >>= \ res ->
292 _ccall_ toClockSec year mon mday hour min sec isDst res
293 >>= \ ptr@(A# ptr#) ->
294 if ptr /= ``NULL'' then
295 return (TOD (int2Integer# (indexIntOffAddr# ptr# 0#)) psec)
297 error "Time.toClockTime: can't perform conversion"
300 isDst = if isdst then (1::Int) else 0
303 bottom = error "Time.bottom"
306 -- (copied from PosixUtil, for now)
307 -- Allocate a mutable array of characters with no indices.
309 allocChars :: Int -> IO (MutableByteArray RealWorld ())
310 allocChars (I# size#) = IO $ \ s# ->
311 case newCharArray# size# s# of
312 StateAndMutableByteArray# s2# barr# ->
313 IOok s2# (MutableByteArray bot barr#)
315 bot = error "Time.allocChars"
317 -- Allocate a mutable array of words with no indices
319 allocWords :: Int -> IO (MutableByteArray RealWorld ())
320 allocWords (I# size#) = IO $ \ s# ->
321 case newIntArray# size# s# of
322 StateAndMutableByteArray# s2# barr# ->
323 IOok s2# (MutableByteArray bot barr#)
325 bot = error "Time.allocWords"
330 calendarTimeToString :: CalendarTime -> String
331 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
333 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
334 formatCalendarTime l fmt ct@(CalendarTime year mon day hour min sec sdec
335 wday yday tzname _ _) =
337 where doFmt ('%':c:cs) = decode c ++ doFmt cs
338 doFmt (c:cs) = c : doFmt cs
340 to12 h = let h' = h `mod` 12 in if h == 0 then 12 else h
341 decode 'A' = fst (wDays l !! fromEnum wday)
342 decode 'a' = snd (wDays l !! fromEnum wday)
343 decode 'B' = fst (months l !! fromEnum mon)
344 decode 'b' = snd (months l !! fromEnum mon)
345 decode 'h' = snd (months l !! fromEnum mon)
346 decode 'C' = show2 (year `quot` 100)
347 decode 'c' = doFmt (dateTimeFmt l)
348 decode 'D' = doFmt "%m/%d/%y"
349 decode 'd' = show2 day
350 decode 'e' = show2' day
351 decode 'H' = show2 hour
352 decode 'I' = show2 (to12 hour)
353 decode 'j' = show3 yday
354 decode 'k' = show2' hour
355 decode 'l' = show2' (to12 hour)
356 decode 'M' = show2 min
357 decode 'm' = show2 (fromEnum mon+1)
359 decode 'p' = (if hour < 12 then fst else snd) (amPm l)
360 decode 'R' = doFmt "%H:%M"
361 decode 'r' = doFmt (time12Fmt l)
362 decode 'T' = doFmt "%H:%M:%S"
364 decode 'S' = show2 sec
365 decode 's' = show2 sec -- Implementation-dependent, sez the lib doc..
366 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7)
367 decode 'u' = show (let n = fromEnum wday in
368 if n == 0 then 7 else n)
371 (yday + 7 - if fromEnum wday > 0 then
372 fromEnum wday - 1 else 6) `divMod` 7
373 in show2 (if days >= 4 then
375 else if week == 0 then 53 else week)
378 show2 ((yday + 7 - if fromEnum wday > 0 then
379 fromEnum wday - 1 else 6) `div` 7)
380 decode 'w' = show (fromEnum wday)
381 decode 'X' = doFmt (timeFmt l)
382 decode 'x' = doFmt (dateFmt l)
383 decode 'Y' = show year
384 decode 'y' = show2 (year `rem` 100)
389 show2, show2', show3 :: Int -> String
390 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
392 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
394 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)