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" #-}
19 CalendarTime(CalendarTime),
21 ClockTime(..), -- non-standard, lib. report gives this as abstract
22 getClockTime, addToClockTime, diffClockTimes,
23 toCalendarTime, toUTCTime, toClockTime,
24 calendarTimeToString, formatCalendarTime
32 import UnsafeST ( unsafePerformPrimIO )
35 import Foreign ( Addr(..) )
36 import Char ( intToDigit )
37 import PackBase ( unpackCString )
42 One way to partition and give name to chunks of a year and a week:
46 = January | February | March | April
47 | May | June | July | August
48 | September | October | November | December
49 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
52 = Sunday | Monday | Tuesday | Wednesday
53 | Thursday | Friday | Saturday
54 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
58 @ClockTime@ is an abstract type, used for the internal clock time.
59 Clock times may be compared, converted to strings, or converted to an
60 external calendar time @CalendarTime@.
63 data ClockTime = TOD Integer Integer deriving (Eq, Ord)
66 When a @ClockTime@ is shown, it is converted to a string of the form
67 @"Mon Nov 28 21:45:41 GMT 1994"@.
69 For now, we are restricted to roughly:
70 Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
71 we use the C library routines based on 32 bit integers.
74 instance Show ClockTime where
75 showsPrec p (TOD sec@(J# a# s# d#) nsec) = showString $ unsafePerformPrimIO $
76 allocChars 32 >>= \ buf ->
77 _ccall_ showTime (I# s#) (ByteArray bottom d#) buf
79 return (unpackCString str)
81 showList = showList__ (showsPrec 0)
85 @CalendarTime@ is a user-readable and manipulable
86 representation of the internal $ClockTime$ type. The
87 numeric fields have the following ranges.
93 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
94 mon 0 .. 11 [Jan = 0, Dec = 11]
98 sec 0 .. 61 [Allows for two leap seconds]
99 picosec 0 .. (10^12)-1 [This could be over-precise?]
100 wday 0 .. 6 [Sunday = 0, Saturday = 6]
101 yday 0 .. 365 [364 in non-Leap years]
102 tz -43200 .. 43200 [Variation from UTC in seconds]
105 The {\em tzname} field is the name of the time zone. The {\em isdst}
106 field indicates whether Daylight Savings Time would be in effect.
117 ctPicosec :: Integer,
124 deriving (Eq,Ord,Read,Show)
128 The @TimeDiff@ type records the difference between two clock times in
140 tdPicosec :: Integer -- not standard
142 deriving (Eq,Ord,Read,Show)
145 @getClockTime@ returns the current time in its internal representation.
148 getClockTime :: IO ClockTime
150 malloc1 `thenIO_Prim` \ i1 ->
151 malloc1 `thenIO_Prim` \ i2 ->
152 _ccall_ getClockTime i1 i2 `thenIO_Prim` \ rc ->
154 cvtUnsigned i1 `thenIO_Prim` \ sec ->
155 cvtUnsigned i2 `thenIO_Prim` \ nsec ->
156 return (TOD sec (nsec * 1000))
158 constructErrorAndFail "getClockTime"
160 malloc1 = ST $ \ s# ->
161 case newIntArray# 1# s# of
162 StateAndMutableByteArray# s2# barr# ->
163 STret s2# (MutableByteArray bottom barr#)
165 -- The C routine fills in an unsigned word. We don't have
166 -- `unsigned2Integer#,' so we freeze the data bits and use them
167 -- for an MP_INT structure. Note that zero is still handled specially,
168 -- although (J# 1# 1# (ptr to 0#)) is probably acceptable to gmp.
170 cvtUnsigned (MutableByteArray _ arr#) = ST $ \ s# ->
171 case readIntArray# arr# 0# s# of
172 StateAndInt# s2# r# ->
176 case unsafeFreezeByteArray# arr# s2# of
177 StateAndByteArray# s3# frozen# ->
178 STret s3# (J# 1# 1# frozen#)
182 @addToClockTime@ {\em d} {\em t} adds a time difference {\em d} and a
183 clock time {\em t} to yield a new clock time. The difference {\em d}
184 may be either positive or negative. @[diffClockTimes@ {\em t1} {\em
185 t2} returns the difference between two clock times {\em t1} and {\em
190 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
191 addToClockTime (TimeDiff year mon day hour min sec psec)
192 (TOD c_sec c_psec) = unsafePerformPrimIO $
193 allocWords (``sizeof(time_t)'') >>= \ res ->
194 _ccall_ toClockSec year mon day hour min sec 0 res
195 >>= \ ptr@(A# ptr#) ->
196 if ptr /= ``NULL'' then
198 diff_sec = (int2Integer# (indexIntOffAddr# ptr# 0#))
201 return (TOD (c_sec + diff_sec) (c_psec + diff_psec))
203 error "Time.addToClockTime: can't perform conversion of TimeDiff"
206 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
207 diffClockTimes tod_a tod_b =
209 CalendarTime year_a mon_a day_a hour_a min_a sec_a psec_a _ _ _ _ _ = toCalendarTime tod_a
210 CalendarTime year_b mon_b day_b hour_b min_b sec_b psec_b _ _ _ _ _ = toCalendarTime tod_b
212 TimeDiff (year_a - year_b)
221 @toCalendarTime@ {\em t} converts {\em t} to a local time, modified by
222 the current timezone and daylight savings time settings. @toUTCTime@
223 {\em t} converts {\em t} into UTC time. @toClockTime@ {\em l}
224 converts {\em l} into the corresponding internal @ClockTime@. The
225 {\em wday}, {\em yday}, {\em tzname}, and {\em isdst} fields are
229 toCalendarTime :: ClockTime -> CalendarTime
230 toCalendarTime (TOD sec@(J# a# s# d#) psec) = unsafePerformPrimIO $
231 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
232 allocChars 32 >>= \ zoneNm ->
233 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
234 _ccall_ toLocalTime (I# s#) (ByteArray bottom d#) res
236 if tm == (``NULL''::Addr) then
237 error "Time.toCalendarTime: out of range"
239 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
240 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
241 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
242 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
243 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
244 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
245 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
246 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
247 _casm_ ``%r = ((struct tm *)%0)->tm_isdst;'' tm >>= \ isdst ->
248 _ccall_ ZONE tm >>= \ zone ->
249 _ccall_ GMTOFF tm >>= \ tz ->
251 tzname = unpackCString zone
253 returnPrimIO (CalendarTime (1900+year) mon mday hour min sec psec
254 (toEnum wday) yday tzname tz (isdst /= 0))
256 toUTCTime :: ClockTime -> CalendarTime
257 toUTCTime (TOD sec@(J# a# s# d#) psec) = unsafePerformPrimIO (
258 allocWords (``sizeof(struct tm)''::Int) >>= \ res ->
259 allocChars 32 >>= \ zoneNm ->
260 _casm_ ``SETZONE((struct tm *)%0,(char *)%1); '' res zoneNm >>= \ () ->
261 _ccall_ toUTCTime (I# s#) (ByteArray bottom d#) res
263 if tm == (``NULL''::Addr) then
264 error "Time.toUTCTime: out of range"
266 _casm_ ``%r = ((struct tm *)%0)->tm_sec;'' tm >>= \ sec ->
267 _casm_ ``%r = ((struct tm *)%0)->tm_min;'' tm >>= \ min ->
268 _casm_ ``%r = ((struct tm *)%0)->tm_hour;'' tm >>= \ hour ->
269 _casm_ ``%r = ((struct tm *)%0)->tm_mday;'' tm >>= \ mday ->
270 _casm_ ``%r = ((struct tm *)%0)->tm_mon;'' tm >>= \ mon ->
271 _casm_ ``%r = ((struct tm *)%0)->tm_year;'' tm >>= \ year ->
272 _casm_ ``%r = ((struct tm *)%0)->tm_wday;'' tm >>= \ wday ->
273 _casm_ ``%r = ((struct tm *)%0)->tm_yday;'' tm >>= \ yday ->
274 returnPrimIO (CalendarTime (1900+year) mon mday hour min sec psec
275 (toEnum wday) yday "UTC" 0 False)
278 toClockTime :: CalendarTime -> ClockTime
279 toClockTime (CalendarTime year mon mday hour min sec psec wday yday tzname tz isdst) =
280 if psec < 0 || psec > 999999999999 then
281 error "Time.toClockTime: picoseconds out of range"
282 else if tz < -43200 || tz > 43200 then
283 error "Time.toClockTime: timezone offset out of range"
285 unsafePerformPrimIO (
286 allocWords (``sizeof(time_t)'') >>= \ res ->
287 _ccall_ toClockSec year mon mday hour min sec isDst res
288 >>= \ ptr@(A# ptr#) ->
289 if ptr /= ``NULL'' then
290 returnPrimIO (TOD (int2Integer# (indexIntOffAddr# ptr# 0#)) psec)
292 error "Time.toClockTime: can't perform conversion"
295 isDst = if isdst then (1::Int) else 0
298 bottom = error "Time.bottom"
301 -- (copied from PosixUtil, for now)
302 -- Allocate a mutable array of characters with no indices.
304 allocChars :: Int -> ST s (MutableByteArray s ())
305 allocChars (I# size#) = ST $ \ s# ->
306 case newCharArray# size# s# of
307 StateAndMutableByteArray# s2# barr# ->
308 STret s2# (MutableByteArray bot barr#)
310 bot = error "Time.allocChars"
312 -- Allocate a mutable array of words with no indices
314 allocWords :: Int -> ST s (MutableByteArray s ())
315 allocWords (I# size#) = ST $ \ s# ->
316 case newIntArray# size# s# of
317 StateAndMutableByteArray# s2# barr# ->
318 STret s2# (MutableByteArray bot barr#)
320 bot = error "Time.allocWords"
325 calendarTimeToString :: CalendarTime -> String
326 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
328 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
329 formatCalendarTime l fmt ct@(CalendarTime year mon day hour min sec sdec
330 wday yday tzname _ _) =
332 where doFmt ('%':c:cs) = decode c ++ doFmt cs
333 doFmt (c:cs) = c : doFmt cs
335 to12 h = let h' = h `mod` 12 in if h == 0 then 12 else h
336 decode 'A' = fst (wDays l !! fromEnum wday)
337 decode 'a' = snd (wDays l !! fromEnum wday)
338 decode 'B' = fst (months l !! fromEnum mon)
339 decode 'b' = snd (months l !! fromEnum mon)
340 decode 'h' = snd (months l !! fromEnum mon)
341 decode 'C' = show2 (year `quot` 100)
342 decode 'c' = doFmt (dateTimeFmt l)
343 decode 'D' = doFmt "%m/%d/%y"
344 decode 'd' = show2 day
345 decode 'e' = show2' day
346 decode 'H' = show2 hour
347 decode 'I' = show2 (to12 hour)
348 decode 'j' = show3 yday
349 decode 'k' = show2' hour
350 decode 'l' = show2' (to12 hour)
351 decode 'M' = show2 min
352 decode 'm' = show2 (fromEnum mon+1)
354 decode 'p' = (if hour < 12 then fst else snd) (amPm l)
355 decode 'R' = doFmt "%H:%M"
356 decode 'r' = doFmt (time12Fmt l)
357 decode 'T' = doFmt "%H:%M:%S"
359 decode 'S' = show2 sec
360 decode 's' = show2 sec -- Implementation-dependent, sez the lib doc..
361 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7)
362 decode 'u' = show (let n = fromEnum wday in
363 if n == 0 then 7 else n)
366 (yday + 7 - if fromEnum wday > 0 then
367 fromEnum wday - 1 else 6) `divMod` 7
368 in show2 (if days >= 4 then
370 else if week == 0 then 53 else week)
373 show2 ((yday + 7 - if fromEnum wday > 0 then
374 fromEnum wday - 1 else 6) `div` 7)
375 decode 'w' = show (fromEnum wday)
376 decode 'X' = doFmt (timeFmt l)
377 decode 'x' = doFmt (dateFmt l)
378 decode 'Y' = show year
379 decode 'y' = show2 (year `rem` 100)
384 show2, show2', show3 :: Int -> String
385 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
387 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
389 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)