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
38 import Unsafe ( unsafePerformIO )
42 import Char ( intToDigit )
43 import PackBase ( unpackCString )
48 One way to partition and give name to chunks of a year and a week:
52 = January | February | March | April
53 | May | June | July | August
54 | September | October | November | December
55 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
58 = Sunday | Monday | Tuesday | Wednesday
59 | Thursday | Friday | Saturday
60 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
64 @ClockTime@ is an abstract type, used for the internal clock time.
65 Clock times may be compared, converted to strings, or converted to an
66 external calendar time @CalendarTime@.
69 data ClockTime = TOD Integer Integer deriving (Eq, Ord)
72 When a @ClockTime@ is shown, it is converted to a string of the form
73 @"Mon Nov 28 21:45:41 GMT 1994"@.
75 For now, we are restricted to roughly:
76 Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
77 we use the C library routines based on 32 bit integers.
80 instance Show ClockTime where
81 showsPrec p (TOD sec@(J# a# s# d#) nsec) = showString $ unsafePerformIO $
82 allocChars 32 >>= \ buf ->
83 _ccall_ showTime (I# s#) (ByteArray bottom d#) buf
85 return (unpackCString str)
87 showList = showList__ (showsPrec 0)
91 @CalendarTime@ is a user-readable and manipulable
92 representation of the internal $ClockTime$ type. The
93 numeric fields have the following ranges.
99 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
100 mon 0 .. 11 [Jan = 0, Dec = 11]
104 sec 0 .. 61 [Allows for two leap seconds]
105 picosec 0 .. (10^12)-1 [This could be over-precise?]
106 wday 0 .. 6 [Sunday = 0, Saturday = 6]
107 yday 0 .. 365 [364 in non-Leap years]
108 tz -43200 .. 43200 [Variation from UTC in seconds]
111 The {\em tzname} field is the name of the time zone. The {\em isdst}
112 field indicates whether Daylight Savings Time would be in effect.
123 ctPicosec :: Integer,
130 deriving (Eq,Ord,Read,Show)
134 The @TimeDiff@ type records the difference between two clock times in
146 tdPicosec :: Integer -- not standard
148 deriving (Eq,Ord,Read,Show)
151 @getClockTime@ returns the current time in its internal representation.
154 getClockTime :: IO ClockTime
158 _ccall_ getClockTime i1 i2 >>= \ rc ->
161 cvtUnsigned i1 >>= \ sec ->
162 cvtUnsigned i2 >>= \ nsec ->
163 return (TOD sec (nsec * 1000))
165 constructErrorAndFail "getClockTime"
167 malloc1 = IO $ \ s# ->
168 case newIntArray# 1# s# of
169 StateAndMutableByteArray# s2# barr# ->
170 IOok s2# (MutableByteArray bottom barr#)
172 -- The C routine fills in an unsigned word. We don't have
173 -- `unsigned2Integer#,' so we freeze the data bits and use them
174 -- for an MP_INT structure. Note that zero is still handled specially,
175 -- although (J# 1# 1# (ptr to 0#)) is probably acceptable to gmp.
177 cvtUnsigned (MutableByteArray _ arr#) = IO $ \ s# ->
178 case readIntArray# arr# 0# s# of
179 StateAndInt# s2# r# ->
182 else case unsafeFreezeByteArray# arr# s2# of
183 StateAndByteArray# s3# frozen# ->
184 IOok s3# (J# 1# 1# frozen#)
188 @addToClockTime@ {\em d} {\em t} adds a time difference {\em d} and a
189 clock time {\em t} to yield a new clock time. The difference {\em d}
190 may be either positive or negative. @[diffClockTimes@ {\em t1} {\em
191 t2} returns the difference between two clock times {\em t1} and {\em
196 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
197 addToClockTime (TimeDiff year mon day hour min sec psec)
198 (TOD c_sec c_psec) = unsafePerformIO $
199 allocWords (``sizeof(time_t)'') >>= \ res ->
200 _ccall_ toClockSec year mon day hour min sec 0 res
201 >>= \ ptr@(A# ptr#) ->
204 diff_sec = (int2Integer# (indexIntOffAddr# ptr# 0#))
207 return (TOD (c_sec + diff_sec) (c_psec + diff_psec))
209 error "Time.addToClockTime: can't perform conversion of TimeDiff"
212 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
213 diffClockTimes tod_a tod_b =
215 CalendarTime year_a mon_a day_a hour_a min_a sec_a psec_a _ _ _ _ _ = toCalendarTime tod_a
216 CalendarTime year_b mon_b day_b hour_b min_b sec_b psec_b _ _ _ _ _ = toCalendarTime tod_b
218 TimeDiff (year_a - year_b)
227 @toCalendarTime@ {\em t} converts {\em t} to a local time, modified by
228 the current timezone and daylight savings time settings. @toUTCTime@
229 {\em t} converts {\em t} into UTC time. @toClockTime@ {\em l}
230 converts {\em l} into the corresponding internal @ClockTime@. The
231 {\em wday}, {\em yday}, {\em tzname}, and {\em isdst} fields are
235 toCalendarTime :: ClockTime -> CalendarTime
236 toCalendarTime (TOD sec@(J# a# s# d#) psec) = unsafePerformIO $
237 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
238 allocChars 32 >>= \ zoneNm ->
239 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
240 _ccall_ toLocalTime (I# s#) (ByteArray bottom d#) res
242 if tm == (``NULL''::Addr)
243 then error "Time.toCalendarTime: out of range"
245 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
246 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
247 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
248 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
249 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
250 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
251 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
252 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
253 _casm_ ``%r = ((struct tm *)%0)->tm_isdst;'' tm >>= \ isdst ->
254 _ccall_ ZONE tm >>= \ zone ->
255 _ccall_ GMTOFF tm >>= \ tz ->
257 tzname = unpackCString zone
259 return (CalendarTime (1900+year) mon mday hour min sec psec
260 (toEnum wday) yday tzname tz (isdst /= 0))
262 toUTCTime :: ClockTime -> CalendarTime
263 toUTCTime (TOD sec@(J# a# s# d#) psec) = unsafePerformIO (
264 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
265 allocChars 32 >>= \ zoneNm ->
266 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
267 _ccall_ toUTCTime (I# s#) (ByteArray bottom d#) res
269 if tm == (``NULL''::Addr)
270 then error "Time.toUTCTime: out of range"
272 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
273 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
274 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
275 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
276 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
277 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
278 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
279 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
280 return (CalendarTime (1900+year) mon mday hour min sec psec
281 (toEnum wday) yday "UTC" 0 False)
284 toClockTime :: CalendarTime -> ClockTime
285 toClockTime (CalendarTime year mon mday hour min sec psec wday yday tzname tz isdst) =
286 if psec < 0 || psec > 999999999999 then
287 error "Time.toClockTime: picoseconds out of range"
288 else if tz < -43200 || tz > 43200 then
289 error "Time.toClockTime: timezone offset out of range"
292 allocWords (``sizeof(time_t)'') >>= \ res ->
293 _ccall_ toClockSec year mon mday hour min sec isDst res
294 >>= \ ptr@(A# ptr#) ->
295 if ptr /= ``NULL'' then
296 return (TOD (int2Integer# (indexIntOffAddr# ptr# 0#)) psec)
298 error "Time.toClockTime: can't perform conversion"
301 isDst = if isdst then (1::Int) else 0
304 bottom = error "Time.bottom"
307 -- (copied from PosixUtil, for now)
308 -- Allocate a mutable array of characters with no indices.
310 allocChars :: Int -> IO (MutableByteArray RealWorld ())
311 allocChars (I# size#) = IO $ \ s# ->
312 case newCharArray# size# s# of
313 StateAndMutableByteArray# s2# barr# ->
314 IOok s2# (MutableByteArray bot barr#)
316 bot = error "Time.allocChars"
318 -- Allocate a mutable array of words with no indices
320 allocWords :: Int -> IO (MutableByteArray RealWorld ())
321 allocWords (I# size#) = IO $ \ s# ->
322 case newIntArray# size# s# of
323 StateAndMutableByteArray# s2# barr# ->
324 IOok s2# (MutableByteArray bot barr#)
326 bot = error "Time.allocWords"
331 calendarTimeToString :: CalendarTime -> String
332 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
334 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
335 formatCalendarTime l fmt ct@(CalendarTime year mon day hour min sec sdec
336 wday yday tzname _ _) =
338 where doFmt ('%':c:cs) = decode c ++ doFmt cs
339 doFmt (c:cs) = c : doFmt cs
341 to12 h = let h' = h `mod` 12 in if h == 0 then 12 else h
342 decode 'A' = fst (wDays l !! fromEnum wday)
343 decode 'a' = snd (wDays l !! fromEnum wday)
344 decode 'B' = fst (months l !! fromEnum mon)
345 decode 'b' = snd (months l !! fromEnum mon)
346 decode 'h' = snd (months l !! fromEnum mon)
347 decode 'C' = show2 (year `quot` 100)
348 decode 'c' = doFmt (dateTimeFmt l)
349 decode 'D' = doFmt "%m/%d/%y"
350 decode 'd' = show2 day
351 decode 'e' = show2' day
352 decode 'H' = show2 hour
353 decode 'I' = show2 (to12 hour)
354 decode 'j' = show3 yday
355 decode 'k' = show2' hour
356 decode 'l' = show2' (to12 hour)
357 decode 'M' = show2 min
358 decode 'm' = show2 (fromEnum mon+1)
360 decode 'p' = (if hour < 12 then fst else snd) (amPm l)
361 decode 'R' = doFmt "%H:%M"
362 decode 'r' = doFmt (time12Fmt l)
363 decode 'T' = doFmt "%H:%M:%S"
365 decode 'S' = show2 sec
366 decode 's' = show2 sec -- Implementation-dependent, sez the lib doc..
367 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7)
368 decode 'u' = show (let n = fromEnum wday in
369 if n == 0 then 7 else n)
372 (yday + 7 - if fromEnum wday > 0 then
373 fromEnum wday - 1 else 6) `divMod` 7
374 in show2 (if days >= 4 then
376 else if week == 0 then 53 else week)
379 show2 ((yday + 7 - if fromEnum wday > 0 then
380 fromEnum wday - 1 else 6) `div` 7)
381 decode 'w' = show (fromEnum wday)
382 decode 'X' = doFmt (timeFmt l)
383 decode 'x' = doFmt (dateFmt l)
384 decode 'Y' = show year
385 decode 'y' = show2 (year `rem` 100)
390 show2, show2', show3 :: Int -> String
391 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
393 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
395 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)