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guile/module/srfi/srfi-19.scm
Morgan Smith c7d170c5d1
Fix typos throughout codebase. 
* NEWS:
* README:
* doc/r5rs/r5rs.texi:
* doc/ref/api-data.texi:
* doc/ref/api-debug.texi:
* doc/ref/api-evaluation.texi:
* doc/ref/api-io.texi:
* doc/ref/api-macros.texi:
* doc/ref/api-procedures.texi:
* doc/ref/api-scheduling.texi:
* doc/ref/api-undocumented.texi:
* doc/ref/libguile-concepts.texi:
* doc/ref/posix.texi:
* doc/ref/srfi-modules.texi:
* doc/ref/vm.texi:
* doc/ref/web.texi:
* examples/box-dynamic-module/box.c:
* examples/box-dynamic/box.c:
* examples/box-module/box.c:
* examples/box/box.c:
* examples/safe/safe:
* examples/scripts/README:
* examples/scripts/hello:
* gc-benchmarks/larceny/twobit-input-long.sch:
* gc-benchmarks/larceny/twobit-smaller.sch:
* gc-benchmarks/larceny/twobit.sch:
* libguile/expand.c:
* libguile/load.c:
* libguile/net_db.c:
* libguile/scmsigs.c:
* libguile/srfi-14.c:
* libguile/threads.c:
* meta/guile.m4:
* module/ice-9/match.upstream.scm:
* module/ice-9/ports.scm:
* module/language/cps/graphs.scm:
* module/scripts/doc-snarf.scm:
* module/srfi/srfi-19.scm:
* module/system/repl/command.scm:
* test-suite/tests/srfi-18.test:
Fix typos.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>
2023-07-16 22:09:01 +02:00

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;;; srfi-19.scm --- Time/Date Library
;; Copyright (C) 2001-2003, 2005-2011, 2014, 2016-2018
;; Free Software Foundation, Inc.
;;
;; This library is free software; you can redistribute it and/or
;; modify it under the terms of the GNU Lesser General Public
;; License as published by the Free Software Foundation; either
;; version 3 of the License, or (at your option) any later version.
;;
;; This library is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; Lesser General Public License for more details.
;;
;; You should have received a copy of the GNU Lesser General Public
;; License along with this library; if not, write to the Free Software
;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
;;; Author: Rob Browning <rlb@cs.utexas.edu>
;;; Originally from SRFI reference implementation by Will Fitzgerald.
;;; Commentary:
;; This module is fully documented in the Guile Reference Manual.
;;; Code:
;; FIXME: I haven't checked a decent amount of this code for potential
;; performance improvements, but I suspect that there may be some
;; substantial ones to be realized, esp. in the later "parsing" half
;; of the file, by rewriting the code with use of more Guile native
;; functions that do more work in a "chunk".
;;
;; FIXME: mkoeppe: Time zones are treated a little simplistic in
;; SRFI-19; they are only a numeric offset. Thus, printing time zones
;; (LOCALE-PRINT-TIME-ZONE) can't be implemented sensibly. The
;; functions taking an optional TZ-OFFSET should be extended to take a
;; symbolic time-zone (like "CET"); this string should be stored in
;; the DATE structure.
(define-module (srfi srfi-19)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-6)
#:use-module (srfi srfi-8)
#:use-module (srfi srfi-9)
#:autoload (ice-9 rdelim) (read-line)
#:use-module (ice-9 i18n)
#:replace (current-time)
#:export (;; Constants
time-duration
time-monotonic
time-process
time-tai
time-thread
time-utc
;; Current time and clock resolution
current-date
current-julian-day
current-modified-julian-day
time-resolution
;; Time object and accessors
make-time
time?
time-type
time-nanosecond
time-second
set-time-type!
set-time-nanosecond!
set-time-second!
copy-time
;; Time comparison procedures
time<=?
time<?
time=?
time>=?
time>?
;; Time arithmetic procedures
time-difference
time-difference!
add-duration
add-duration!
subtract-duration
subtract-duration!
;; Date object and accessors
make-date
date?
date-nanosecond
date-second
date-minute
date-hour
date-day
date-month
date-year
date-zone-offset
date-year-day
date-week-day
date-week-number
;; Time/Date/Julian Day/Modified Julian Day converters
date->julian-day
date->modified-julian-day
date->time-monotonic
date->time-tai
date->time-utc
julian-day->date
julian-day->time-monotonic
julian-day->time-tai
julian-day->time-utc
modified-julian-day->date
modified-julian-day->time-monotonic
modified-julian-day->time-tai
modified-julian-day->time-utc
time-monotonic->date
time-monotonic->julian-day
time-monotonic->modified-julian-day
time-monotonic->time-tai
time-monotonic->time-tai!
time-monotonic->time-utc
time-monotonic->time-utc!
time-tai->date
time-tai->julian-day
time-tai->modified-julian-day
time-tai->time-monotonic
time-tai->time-monotonic!
time-tai->time-utc
time-tai->time-utc!
time-utc->date
time-utc->julian-day
time-utc->modified-julian-day
time-utc->time-monotonic
time-utc->time-monotonic!
time-utc->time-tai
time-utc->time-tai!
;; Date to string/string to date converters.
date->string
string->date))
(cond-expand-provide (current-module) '(srfi-19))
(define time-tai 'time-tai)
(define time-utc 'time-utc)
(define time-monotonic 'time-monotonic)
(define time-thread 'time-thread)
(define time-process 'time-process)
(define time-duration 'time-duration)
;; FIXME: do we want to add gc time?
;; (define time-gc 'time-gc)
;;-- LOCALE dependent constants
;; See date->string
(define locale-date-time-format "~a ~b ~d ~H:~M:~S~z ~Y")
(define locale-short-date-format "~m/~d/~y")
(define locale-time-format "~H:~M:~S")
(define iso-8601-date-time-format "~Y-~m-~dT~H:~M:~S~z")
;;-- Miscellaneous Constants.
;;-- only the utc-epoch-in-jd might need changing if
;; a different epoch is used.
(define nano 1000000000) ; nanoseconds in a second
(define sid 86400) ; seconds in a day
(define sihd 43200) ; seconds in a half day
(define utc-epoch-in-jd 4881175/2) ; julian day number for 'the epoch'
;; FIXME: should this be something other than misc-error?
(define (time-error caller type value)
(if value
(throw 'misc-error caller "TIME-ERROR type ~A: ~S" (list type value) #f)
(throw 'misc-error caller "TIME-ERROR type ~A" (list type) #f)))
;; A table of leap seconds
;; See ftp://maia.usno.navy.mil/ser7/tai-utc.dat
;; and update as necessary.
;; this procedures reads the file in the above
;; format and creates the leap second table
;; it also calls the almost standard, but not R5 procedures read-line
;; & open-input-string
;; ie (set! leap-second-table (read-tai-utc-date "tai-utc.dat"))
(define (read-tai-utc-data filename)
(define (convert-jd jd)
(* (- (inexact->exact jd) utc-epoch-in-jd) sid))
(define (convert-sec sec)
(inexact->exact sec))
(let ((port (open-input-file filename))
(table '()))
(let loop ((line (read-line port)))
(if (not (eof-object? line))
(begin
(let* ((data (read (open-input-string
(string-append "(" line ")"))))
(year (car data))
(jd (cadddr (cdr data)))
(secs (cadddr (cdddr data))))
(if (>= year 1972)
(set! table (cons
(cons (convert-jd jd) (convert-sec secs))
table)))
(loop (read-line port))))))
table))
;; each entry is (tai seconds since epoch . # seconds to subtract for utc)
;; note they go higher to lower, and end in 1972.
(define leap-second-table
'((1483228800 . 37)
(1435708800 . 36)
(1341100800 . 35)
(1230768000 . 34)
(1136073600 . 33)
(915148800 . 32)
(867715200 . 31)
(820454400 . 30)
(773020800 . 29)
(741484800 . 28)
(709948800 . 27)
(662688000 . 26)
(631152000 . 25)
(567993600 . 24)
(489024000 . 23)
(425865600 . 22)
(394329600 . 21)
(362793600 . 20)
(315532800 . 19)
(283996800 . 18)
(252460800 . 17)
(220924800 . 16)
(189302400 . 15)
(157766400 . 14)
(126230400 . 13)
(94694400 . 12)
(78796800 . 11)
(63072000 . 10)))
(define (read-leap-second-table filename)
(set! leap-second-table (read-tai-utc-data filename)))
(define (utc->tai utc-seconds)
(let loop ((table leap-second-table))
(cond ((null? table)
utc-seconds)
((>= utc-seconds (caar table))
(+ utc-seconds (cdar table)))
(else
(loop (cdr table))))))
(define (tai->utc tai-seconds)
(let loop ((table leap-second-table))
(cond ((null? table)
tai-seconds)
((>= tai-seconds (+ (caar table) (cdar table)))
(- tai-seconds (cdar table)))
(else
(loop (cdr table))))))
;;; the TIME structure; creates the accessors, too.
(define-record-type time
(make-time-unnormalized type nanosecond second)
time?
(type time-type set-time-type!)
(nanosecond time-nanosecond set-time-nanosecond!)
(second time-second set-time-second!))
(define (copy-time time)
(make-time (time-type time) (time-nanosecond time) (time-second time)))
(define (split-real r)
(if (integer? r)
(values (inexact->exact r) 0)
(let ((l (truncate r)))
(values (inexact->exact l) (- r l)))))
(define (time-normalize! t)
(let ((s (time-second t))
(ns (time-nanosecond t)))
(when (>= (abs (time-nanosecond t))
nano)
(let ((s* (+ s (inexact->exact
(truncate-quotient ns nano))))
(ns* (truncate-remainder ns nano)))
(set-time-second! t s*)
(set-time-nanosecond! t ns*)))
(cond ((and (positive? s) (negative? ns))
(set-time-second! t (- s 1))
(set-time-nanosecond! t (+ ns nano)))
((and (negative? s) (positive? ns))
(set-time-second! t (+ s 1))
(set-time-nanosecond! t (- ns nano))))
t))
(define (make-time type nanosecond second)
(time-normalize! (make-time-unnormalized type nanosecond second)))
;;; current-time
;;; specific time getters.
(define (current-time-utc)
;; Resolution is microseconds.
(let ((tod (gettimeofday)))
(make-time time-utc (* (cdr tod) 1000) (car tod))))
(define (current-time-tai)
;; Resolution is microseconds.
(let* ((tod (gettimeofday))
(sec (car tod))
(usec (cdr tod)))
(make-time time-tai
(* usec 1000)
(utc->tai sec))))
;;(define (current-time-ms-time time-type proc)
;; (let ((current-ms (proc)))
;; (make-time time-type
;; (quotient current-ms 10000)
;; (* (remainder current-ms 1000) 10000))))
;; -- we define it to be the same as TAI.
;; A different implementation of current-time-monotonic
;; will require rewriting all of the time-monotonic converters,
;; of course.
(define (current-time-monotonic)
;; Guile monotonic and TAI times are the same.
(let ((tai (current-time-tai)))
(make-time time-monotonic
(time-nanosecond tai)
(time-second tai))))
(define (current-time-thread)
(time-error 'current-time-thread 'unsupported-clock-type 'time-thread))
(define ns-per-guile-tick (/ 1000000000 internal-time-units-per-second))
(define (current-time-process)
(let ((run-time (get-internal-run-time)))
(make-time
time-process
(* (remainder run-time internal-time-units-per-second)
ns-per-guile-tick)
(quotient run-time internal-time-units-per-second))))
;;(define (current-time-gc)
;; (current-time-ms-time time-gc current-gc-milliseconds))
(define (current-time . clock-type)
(let ((clock-type (if (null? clock-type) time-utc (car clock-type))))
(cond
((eq? clock-type time-tai) (current-time-tai))
((eq? clock-type time-utc) (current-time-utc))
((eq? clock-type time-monotonic) (current-time-monotonic))
((eq? clock-type time-thread) (current-time-thread))
((eq? clock-type time-process) (current-time-process))
;; ((eq? clock-type time-gc) (current-time-gc))
(else (time-error 'current-time 'invalid-clock-type clock-type)))))
;; -- Time Resolution
;; This is the resolution of the clock in nanoseconds.
;; This will be implementation specific.
(define (time-resolution . clock-type)
(let ((clock-type (if (null? clock-type) time-utc (car clock-type))))
(case clock-type
((time-tai) 1000)
((time-utc) 1000)
((time-monotonic) 1000)
((time-process) ns-per-guile-tick)
;; ((eq? clock-type time-thread) 1000)
;; ((eq? clock-type time-gc) 10000)
(else (time-error 'time-resolution 'invalid-clock-type clock-type)))))
;; -- Time comparisons
(define (time-compare-check t1 t2 caller)
(unless (and (time? t1) (time? t2)
(eq? (time-type t1) (time-type t2)))
(time-error caller 'incompatible-time-types (cons t1 t2))))
(define (time=? t1 t2)
;; Arrange tests for speed and presume that t1 and t2 are actually times.
;; also presume it will be rare to check two times of different types.
(time-compare-check t1 t2 'time=?)
(and (= (time-second t1) (time-second t2))
(= (time-nanosecond t1) (time-nanosecond t2))))
(define (time>? t1 t2)
(time-compare-check t1 t2 'time>?)
(or (> (time-second t1) (time-second t2))
(and (= (time-second t1) (time-second t2))
(> (time-nanosecond t1) (time-nanosecond t2)))))
(define (time<? t1 t2)
(time-compare-check t1 t2 'time<?)
(or (< (time-second t1) (time-second t2))
(and (= (time-second t1) (time-second t2))
(< (time-nanosecond t1) (time-nanosecond t2)))))
(define (time>=? t1 t2)
(time-compare-check t1 t2 'time>=?)
(or (> (time-second t1) (time-second t2))
(and (= (time-second t1) (time-second t2))
(>= (time-nanosecond t1) (time-nanosecond t2)))))
(define (time<=? t1 t2)
(time-compare-check t1 t2 'time<=?)
(or (< (time-second t1) (time-second t2))
(and (= (time-second t1) (time-second t2))
(<= (time-nanosecond t1) (time-nanosecond t2)))))
;; -- Time arithmetic
;; XXX In the following comparison procedures, the SRFI-19 reference
;; implementation raises an error in case of unequal time types.
(define (time-difference! time1 time2)
(time-compare-check time1 time2 'time-difference!)
(let ((sec-diff (- (time-second time1) (time-second time2)))
(nsec-diff (- (time-nanosecond time1) (time-nanosecond time2))))
(set-time-type! time1 time-duration)
(set-time-second! time1 sec-diff)
(set-time-nanosecond! time1 nsec-diff)
(time-normalize! time1)))
(define (time-difference time1 time2)
(let ((result (copy-time time1)))
(time-difference! result time2)))
(define (add-duration! t duration)
(if (not (eq? (time-type duration) time-duration))
(time-error 'add-duration! 'not-duration duration)
(let ((sec-plus (+ (time-second t) (time-second duration)))
(nsec-plus (+ (time-nanosecond t) (time-nanosecond duration))))
(set-time-second! t sec-plus)
(set-time-nanosecond! t nsec-plus)
(time-normalize! t))))
(define (add-duration t duration)
(let ((result (copy-time t)))
(add-duration! result duration)))
(define (subtract-duration! t duration)
(if (not (eq? (time-type duration) time-duration))
(time-error 'subtract-duration! 'not-duration duration)
(let ((sec-minus (- (time-second t) (time-second duration)))
(nsec-minus (- (time-nanosecond t) (time-nanosecond duration))))
(set-time-second! t sec-minus)
(set-time-nanosecond! t nsec-minus)
(time-normalize! t))))
(define (subtract-duration time1 duration)
(let ((result (copy-time time1)))
(subtract-duration! result duration)))
;; -- Converters between types.
(define (priv:time-tai->time-utc! time-in time-out caller)
(if (not (eq? (time-type time-in) time-tai))
(time-error caller 'incompatible-time-types time-in))
(set-time-type! time-out time-utc)
(set-time-nanosecond! time-out (time-nanosecond time-in))
(set-time-second! time-out (tai->utc (time-second time-in)))
time-out)
(define (time-tai->time-utc time-in)
(priv:time-tai->time-utc! time-in (make-time-unnormalized #f #f #f) 'time-tai->time-utc))
(define (time-tai->time-utc! time-in)
(priv:time-tai->time-utc! time-in time-in 'time-tai->time-utc!))
(define (priv:time-utc->time-tai! time-in time-out caller)
(if (not (eq? (time-type time-in) time-utc))
(time-error caller 'incompatible-time-types time-in))
(set-time-type! time-out time-tai)
(set-time-nanosecond! time-out (time-nanosecond time-in))
(set-time-second! time-out (utc->tai (time-second time-in)))
time-out)
(define (time-utc->time-tai time-in)
(priv:time-utc->time-tai! time-in (make-time-unnormalized #f #f #f) 'time-utc->time-tai))
(define (time-utc->time-tai! time-in)
(priv:time-utc->time-tai! time-in time-in 'time-utc->time-tai!))
;; -- these depend on time-monotonic having the same definition as time-tai!
(define (time-monotonic->time-utc time-in)
(if (not (eq? (time-type time-in) time-monotonic))
(time-error 'time-monotonic->time-utc
'incompatible-time-types time-in))
(let ((ntime (copy-time time-in)))
(set-time-type! ntime time-tai)
(priv:time-tai->time-utc! ntime ntime 'time-monotonic->time-utc)))
(define (time-monotonic->time-utc! time-in)
(if (not (eq? (time-type time-in) time-monotonic))
(time-error 'time-monotonic->time-utc!
'incompatible-time-types time-in))
(set-time-type! time-in time-tai)
(priv:time-tai->time-utc! time-in time-in 'time-monotonic->time-utc))
(define (time-monotonic->time-tai time-in)
(if (not (eq? (time-type time-in) time-monotonic))
(time-error 'time-monotonic->time-tai
'incompatible-time-types time-in))
(let ((ntime (copy-time time-in)))
(set-time-type! ntime time-tai)
ntime))
(define (time-monotonic->time-tai! time-in)
(if (not (eq? (time-type time-in) time-monotonic))
(time-error 'time-monotonic->time-tai!
'incompatible-time-types time-in))
(set-time-type! time-in time-tai)
time-in)
(define (time-utc->time-monotonic time-in)
(if (not (eq? (time-type time-in) time-utc))
(time-error 'time-utc->time-monotonic
'incompatible-time-types time-in))
(let ((ntime (priv:time-utc->time-tai! time-in (make-time-unnormalized #f #f #f)
'time-utc->time-monotonic)))
(set-time-type! ntime time-monotonic)
ntime))
(define (time-utc->time-monotonic! time-in)
(if (not (eq? (time-type time-in) time-utc))
(time-error 'time-utc->time-monotonic!
'incompatible-time-types time-in))
(let ((ntime (priv:time-utc->time-tai! time-in time-in
'time-utc->time-monotonic!)))
(set-time-type! ntime time-monotonic)
ntime))
(define (time-tai->time-monotonic time-in)
(if (not (eq? (time-type time-in) time-tai))
(time-error 'time-tai->time-monotonic
'incompatible-time-types time-in))
(let ((ntime (copy-time time-in)))
(set-time-type! ntime time-monotonic)
ntime))
(define (time-tai->time-monotonic! time-in)
(if (not (eq? (time-type time-in) time-tai))
(time-error 'time-tai->time-monotonic!
'incompatible-time-types time-in))
(set-time-type! time-in time-monotonic)
time-in)
;; -- Date Structures
;; FIXME: to be really safe, perhaps we should normalize the
;; seconds/nanoseconds/minutes coming in to make-date...
(define-record-type date
(make-date nanosecond second minute
hour day month
year
zone-offset)
date?
(nanosecond date-nanosecond set-date-nanosecond!)
(second date-second set-date-second!)
(minute date-minute set-date-minute!)
(hour date-hour set-date-hour!)
(day date-day set-date-day!)
(month date-month set-date-month!)
(year date-year set-date-year!)
(zone-offset date-zone-offset set-date-zone-offset!))
;; gives the julian day which starts at noon.
(define (encode-julian-day-number day month year)
(let* ((a (quotient (- 14 month) 12))
(y (- (+ year 4800) a (if (negative? year) -1 0)))
(m (- (+ month (* 12 a)) 3)))
(+ day
(quotient (+ (* 153 m) 2) 5)
(* 365 y)
(floor-quotient y 4)
(- (floor-quotient y 100))
(floor-quotient y 400)
-32045)))
;; gives the seconds/date/month/year
(define (decode-julian-day-number jdn)
(let* ((days (inexact->exact (floor jdn)))
(a (+ days 32044))
(b (floor-quotient (+ (* 4 a) 3) 146097))
(c (- a (floor-quotient (* 146097 b) 4)))
(d (floor-quotient (+ (* 4 c) 3) 1461))
(e (- c (floor-quotient (* 1461 d) 4)))
(m (floor-quotient (+ (* 5 e) 2) 153))
(y (+ (* 100 b) d -4800 (quotient m 10))))
(values ; seconds date month year
(* (- jdn days) sid)
(+ e (- (quotient (+ (* 153 m) 2) 5)) 1)
(+ m 3 (* -12 (quotient m 10)))
(if (>= 0 y) (- y 1) y))))
;; relies on the fact that we named our time zone accessor
;; differently from MzScheme's....
;; This should be written to be OS specific.
(define (local-tz-offset utc-time)
;; SRFI 19 uses seconds East, but 'tm:gmtoff' returns seconds West.
(- (tm:gmtoff (localtime (time-second utc-time)))))
;; special thing -- ignores nanos
(define (time->julian-day-number seconds tz-offset)
(+ (/ (+ seconds tz-offset sihd)
sid)
utc-epoch-in-jd))
(define (tai-before-leap-second? second)
(any (lambda (x)
(= second (+ (car x) (cdr x) -1)))
leap-second-table))
(define* (time-utc->date time #:optional (tz-offset
(local-tz-offset time)))
(if (not (eq? (time-type time) time-utc))
(time-error 'time-utc->date 'incompatible-time-types time))
(let* ((nanoseconds (+ (time-nanosecond time)
(* nano (time-second time))))
(jdn (time->julian-day-number (floor-quotient nanoseconds nano)
tz-offset)))
(call-with-values (lambda () (decode-julian-day-number jdn))
(lambda (secs date month year)
;; secs is a real because jdn is a real in Guile;
;; but it is conceptionally an integer.
(let* ((int-secs (inexact->exact (round secs)))
(hours (quotient int-secs (* 60 60)))
(rem (remainder int-secs (* 60 60)))
(minutes (quotient rem 60))
(seconds (remainder rem 60)))
(make-date (floor-remainder nanoseconds nano)
seconds
minutes
hours
date
month
year
tz-offset))))))
(define (time-tai->date time . tz-offset)
(if (not (eq? (time-type time) time-tai))
(time-error 'time-tai->date 'incompatible-time-types time))
(if (tai-before-leap-second? (time-second time))
;; If it's *right* before the leap, we must handle this case to
;; avoid the information lost when converting to UTC. We subtract
;; a second before conversion, and then effectively add it back
;; after conversion by setting the second field to 60.
(let ((d (apply time-utc->date
(subtract-duration! (time-tai->time-utc time)
(make-time time-duration 0 1))
tz-offset)))
(set-date-second! d 60)
d)
(apply time-utc->date (time-tai->time-utc time) tz-offset)))
(define (time-monotonic->date time . tz-offset)
(if (not (eq? (time-type time) time-monotonic))
(time-error 'time-monotonic->date 'incompatible-time-types time))
(apply time-tai->date (time-monotonic->time-tai time) tz-offset))
(define (date->time-utc date)
(let* ((jdays (- (encode-julian-day-number (date-day date)
(date-month date)
(date-year date))
utc-epoch-in-jd))
;; jdays is an integer plus 1/2,
(jdays-1/2 (inexact->exact (- jdays 1/2))))
(make-time
time-utc
(date-nanosecond date)
(+ (* jdays-1/2 24 60 60)
(* (date-hour date) 60 60)
(* (date-minute date) 60)
(date-second date)
(- (date-zone-offset date))))))
(define (date->time-tai d)
(if (= (date-second d) 60)
(subtract-duration! (time-utc->time-tai! (date->time-utc d))
(make-time time-duration 0 1))
(time-utc->time-tai! (date->time-utc d))))
(define (date->time-monotonic d)
(if (= (date-second d) 60)
(subtract-duration! (time-utc->time-monotonic! (date->time-utc d))
(make-time time-duration 0 1))
(time-utc->time-monotonic! (date->time-utc d))))
(define (leap-year? year)
(let ((y (if (negative? year) (+ year 1) year)))
(and (zero? (modulo y 4))
(or (not (zero? (modulo y 100)))
(zero? (modulo y 400))))))
;; Map 1-based month number M to number of days in the year before the
;; start of month M (in a non-leap year).
(define month-assoc '((1 . 0) (2 . 31) (3 . 59) (4 . 90)
(5 . 120) (6 . 151) (7 . 181) (8 . 212)
(9 . 243) (10 . 273) (11 . 304) (12 . 334)))
(define (year-day day month year)
(let ((days-pr (assoc month month-assoc)))
(if (not days-pr)
(time-error 'date-year-day 'invalid-month-specification month))
(if (and (leap-year? year) (> month 2))
(+ day (cdr days-pr) 1)
(+ day (cdr days-pr)))))
(define (date-year-day date)
(year-day (date-day date) (date-month date) (date-year date)))
;; from calendar faq
(define (week-day day month year)
(let* ((yy (if (negative? year) (+ year 1) year))
(a (quotient (- 14 month) 12))
(y (- yy a))
(m (+ month (* 12 a) -2)))
(modulo (+ day
y
(floor-quotient y 4)
(- (floor-quotient y 100))
(floor-quotient y 400)
(floor-quotient (* 31 m) 12))
7)))
(define (date-week-day date)
(week-day (date-day date) (date-month date) (date-year date)))
(define (days-before-first-week date day-of-week-starting-week)
(let* ((first-day (make-date 0 0 0 0
1
1
(date-year date)
#f))
(fdweek-day (date-week-day first-day)))
(modulo (- day-of-week-starting-week fdweek-day)
7)))
;; The "-1" here is a fix for the reference implementation, to make a new
;; week start on the given day-of-week-starting-week. date-year-day returns
;; a day starting from 1 for 1st Jan.
;;
(define (date-week-number date day-of-week-starting-week)
(floor-quotient (- (date-year-day date)
1
(days-before-first-week date day-of-week-starting-week))
7))
(define (current-date . tz-offset)
(let ((time (current-time time-utc)))
(time-utc->date
time
(if (null? tz-offset)
(local-tz-offset time)
(car tz-offset)))))
;; given a 'two digit' number, find the year within 50 years +/-
(define (natural-year n)
(let* ((current-year (date-year (current-date)))
(current-century (* (quotient current-year 100) 100)))
(cond
((>= n 100) n)
((< n 0) n)
((<= (- (+ current-century n) current-year) 50) (+ current-century n))
(else (+ (- current-century 100) n)))))
(define (date->julian-day date)
(let ((nanosecond (date-nanosecond date))
(second (date-second date))
(minute (date-minute date))
(hour (date-hour date))
(day (date-day date))
(month (date-month date))
(year (date-year date))
(offset (date-zone-offset date)))
(+ (encode-julian-day-number day month year)
(- 1/2)
(+ (/ (+ (- offset)
(* hour 60 60)
(* minute 60)
second
(/ nanosecond nano))
sid)))))
(define (date->modified-julian-day date)
(- (date->julian-day date)
4800001/2))
(define (time-utc->julian-day time)
(if (not (eq? (time-type time) time-utc))
(time-error 'time-utc->julian-day 'incompatible-time-types time))
(+ (/ (+ (time-second time) (/ (time-nanosecond time) nano))
sid)
utc-epoch-in-jd))
(define (time-utc->modified-julian-day time)
(- (time-utc->julian-day time)
4800001/2))
(define (time-tai->julian-day time)
(if (not (eq? (time-type time) time-tai))
(time-error 'time-tai->julian-day 'incompatible-time-types time))
(+ (/ (+ (tai->utc (time-second time))
(/ (time-nanosecond time) nano))
sid)
utc-epoch-in-jd))
(define (time-tai->modified-julian-day time)
(- (time-tai->julian-day time)
4800001/2))
;; this is the same as time-tai->julian-day
(define (time-monotonic->julian-day time)
(if (not (eq? (time-type time) time-monotonic))
(time-error 'time-monotonic->julian-day 'incompatible-time-types time))
(+ (/ (+ (tai->utc (time-second time))
(/ (time-nanosecond time) nano))
sid)
utc-epoch-in-jd))
(define (time-monotonic->modified-julian-day time)
(- (time-monotonic->julian-day time)
4800001/2))
(define (julian-day->time-utc jdn)
(let ((secs (* sid (- jdn utc-epoch-in-jd))))
(receive (seconds parts)
(split-real secs)
(make-time time-utc
(* parts nano)
seconds))))
(define (julian-day->time-tai jdn)
(time-utc->time-tai! (julian-day->time-utc jdn)))
(define (julian-day->time-monotonic jdn)
(time-utc->time-monotonic! (julian-day->time-utc jdn)))
(define (julian-day->date jdn . tz-offset)
(let* ((time (julian-day->time-utc jdn))
(offset (if (null? tz-offset)
(local-tz-offset time)
(car tz-offset))))
(time-utc->date time offset)))
(define (modified-julian-day->date jdn . tz-offset)
(apply julian-day->date (+ jdn 4800001/2)
tz-offset))
(define (modified-julian-day->time-utc jdn)
(julian-day->time-utc (+ jdn 4800001/2)))
(define (modified-julian-day->time-tai jdn)
(julian-day->time-tai (+ jdn 4800001/2)))
(define (modified-julian-day->time-monotonic jdn)
(julian-day->time-monotonic (+ jdn 4800001/2)))
(define (current-julian-day)
(time-utc->julian-day (current-time time-utc)))
(define (current-modified-julian-day)
(time-utc->modified-julian-day (current-time time-utc)))
;; returns a string rep. of number N, of minimum LENGTH, padded with
;; character PAD-WITH. If PAD-WITH is #f, no padding is done, and it's
;; as if number->string was used. if string is longer than or equal
;; in length to LENGTH, it's as if number->string was used.
(define (padding n pad-with length)
(let* ((str (number->string n))
(str-len (string-length str)))
(if (or (>= str-len length)
(not pad-with))
str
(string-append (make-string (- length str-len) pad-with) str))))
(define (last-n-digits i n)
(abs (remainder i (expt 10 n))))
(define (locale-abbr-weekday n) (locale-day-short (+ 1 n)))
(define (locale-long-weekday n) (locale-day (+ 1 n)))
(define locale-abbr-month locale-month-short)
(define locale-long-month locale-month)
(define (date-reverse-lookup needle haystack-ref haystack-len
same?)
;; Lookup NEEDLE (a string) using HAYSTACK-REF (a one argument procedure
;; that returns a string corresponding to the given index) by passing it
;; indices lower than HAYSTACK-LEN.
(let loop ((index 1))
(cond ((> index haystack-len) #f)
((same? needle (haystack-ref index))
index)
(else (loop (+ index 1))))))
(define (locale-abbr-weekday->index string)
(date-reverse-lookup string locale-day-short 7 string=?))
(define (locale-long-weekday->index string)
(date-reverse-lookup string locale-day 7 string=?))
(define (locale-abbr-month->index string)
(date-reverse-lookup string locale-abbr-month 12 string=?))
(define (locale-long-month->index string)
(date-reverse-lookup string locale-long-month 12 string=?))
;; FIXME: mkoeppe: Put a symbolic time zone in the date structs.
;; Print it here instead of the numerical offset if available.
(define (locale-print-time-zone date port)
(tz-printer (date-zone-offset date) port))
(define (locale-am-string/pm hr)
(if (> hr 11) (locale-pm-string) (locale-am-string)))
(define (tz-printer offset port)
(cond
((= offset 0) (display "Z" port))
((negative? offset) (display "-" port))
(else (display "+" port)))
(if (not (= offset 0))
(let ((hours (abs (quotient offset (* 60 60))))
(minutes (abs (quotient (remainder offset (* 60 60)) 60))))
(display (padding hours #\0 2) port)
(display (padding minutes #\0 2) port))))
;; A table of output formatting directives.
;; the first time is the format char.
;; the second is a procedure that takes the date, a padding character
;; (which might be #f), and the output port.
;;
(define directives
(list
(cons #\~ (lambda (date pad-with port)
(display #\~ port)))
(cons #\a (lambda (date pad-with port)
(display (locale-abbr-weekday (date-week-day date))
port)))
(cons #\A (lambda (date pad-with port)
(display (locale-long-weekday (date-week-day date))
port)))
(cons #\b (lambda (date pad-with port)
(display (locale-abbr-month (date-month date))
port)))
(cons #\B (lambda (date pad-with port)
(display (locale-long-month (date-month date))
port)))
(cons #\c (lambda (date pad-with port)
(display (date->string date locale-date-time-format) port)))
(cons #\d (lambda (date pad-with port)
(display (padding (date-day date)
#\0 2)
port)))
(cons #\D (lambda (date pad-with port)
(display (date->string date "~m/~d/~y") port)))
(cons #\e (lambda (date pad-with port)
(display (padding (date-day date)
#\Space 2)
port)))
(cons #\f (lambda (date pad-with port)
(receive (s ns) (floor/ (+ (* (date-second date) nano)
(date-nanosecond date))
nano)
(display (number->string s) port)
(display (locale-decimal-point) port)
(let ((str (padding ns #\0 9)))
(display (substring str 0 1) port)
(display (string-trim-right str #\0 1) port)))))
(cons #\h (lambda (date pad-with port)
(display (date->string date "~b") port)))
(cons #\H (lambda (date pad-with port)
(display (padding (date-hour date)
pad-with 2)
port)))
(cons #\I (lambda (date pad-with port)
(let ((hr (date-hour date)))
(if (> hr 12)
(display (padding (- hr 12)
pad-with 2)
port)
(display (padding hr
pad-with 2)
port)))))
(cons #\j (lambda (date pad-with port)
(display (padding (date-year-day date)
pad-with 3)
port)))
(cons #\k (lambda (date pad-with port)
(display (padding (date-hour date)
#\Space 2)
port)))
(cons #\l (lambda (date pad-with port)
(let ((hr (if (> (date-hour date) 12)
(- (date-hour date) 12) (date-hour date))))
(display (padding hr #\Space 2)
port))))
(cons #\m (lambda (date pad-with port)
(display (padding (date-month date)
pad-with 2)
port)))
(cons #\M (lambda (date pad-with port)
(display (padding (date-minute date)
pad-with 2)
port)))
(cons #\n (lambda (date pad-with port)
(newline port)))
(cons #\N (lambda (date pad-with port)
(display (padding (date-nanosecond date)
pad-with 9)
port)))
(cons #\p (lambda (date pad-with port)
(display (locale-am-string/pm (date-hour date)) port)))
(cons #\r (lambda (date pad-with port)
(display (date->string date "~I:~M:~S ~p") port)))
(cons #\s (lambda (date pad-with port)
(display (time-second (date->time-utc date)) port)))
(cons #\S (lambda (date pad-with port)
(if (> (date-nanosecond date)
nano)
(display (padding (+ (date-second date) 1)
pad-with 2)
port)
(display (padding (date-second date)
pad-with 2)
port))))
(cons #\t (lambda (date pad-with port)
(display #\Tab port)))
(cons #\T (lambda (date pad-with port)
(display (date->string date "~H:~M:~S") port)))
(cons #\U (lambda (date pad-with port)
(if (> (days-before-first-week date 0) 0)
(display (padding (+ (date-week-number date 0) 1)
#\0 2) port)
(display (padding (date-week-number date 0)
#\0 2) port))))
(cons #\V (lambda (date pad-with port)
(display (padding (date-week-number date 1)
#\0 2) port)))
(cons #\w (lambda (date pad-with port)
(display (date-week-day date) port)))
(cons #\x (lambda (date pad-with port)
(display (date->string date locale-short-date-format) port)))
(cons #\X (lambda (date pad-with port)
(display (date->string date locale-time-format) port)))
(cons #\W (lambda (date pad-with port)
(if (> (days-before-first-week date 1) 0)
(display (padding (+ (date-week-number date 1) 1)
#\0 2) port)
(display (padding (date-week-number date 1)
#\0 2) port))))
(cons #\y (lambda (date pad-with port)
(display (padding (last-n-digits
(date-year date) 2)
pad-with
2)
port)))
(cons #\Y (lambda (date pad-with port)
(let* ((yy (date-year date))
(y (if (negative? yy) (+ yy 1) yy)))
(unless (<= 0 y 9999)
(display (if (negative? y) #\- #\+) port))
(display (padding (abs y) pad-with 4) port))))
(cons #\z (lambda (date pad-with port)
(tz-printer (date-zone-offset date) port)))
(cons #\Z (lambda (date pad-with port)
(locale-print-time-zone date port)))
(cons #\1 (lambda (date pad-with port)
(display (date->string date "~Y-~m-~d") port)))
(cons #\2 (lambda (date pad-with port)
(display (date->string date "~H:~M:~S~z") port)))
(cons #\3 (lambda (date pad-with port)
(display (date->string date "~H:~M:~S") port)))
(cons #\4 (lambda (date pad-with port)
(display (date->string date "~Y-~m-~dT~H:~M:~S~z") port)))
(cons #\5 (lambda (date pad-with port)
(display (date->string date "~Y-~m-~dT~H:~M:~S") port)))))
(define (get-formatter char)
(let ((associated (assoc char directives)))
(if associated (cdr associated) #f)))
(define (date-printer date index format-string str-len port)
(if (< index str-len)
(let ((current-char (string-ref format-string index)))
(if (not (char=? current-char #\~))
(begin
(display current-char port)
(date-printer date (+ index 1) format-string str-len port))
(if (= (+ index 1) str-len) ; bad format string.
(time-error 'date-printer 'bad-date-format-string
format-string)
(let ((pad-char? (string-ref format-string (+ index 1))))
(cond
((char=? pad-char? #\-)
(if (= (+ index 2) str-len) ; bad format string.
(time-error 'date-printer
'bad-date-format-string
format-string)
(let ((formatter (get-formatter
(string-ref format-string
(+ index 2)))))
(if (not formatter)
(time-error 'date-printer
'bad-date-format-string
format-string)
(begin
(formatter date #f port)
(date-printer date
(+ index 3)
format-string
str-len
port))))))
((char=? pad-char? #\_)
(if (= (+ index 2) str-len) ; bad format string.
(time-error 'date-printer
'bad-date-format-string
format-string)
(let ((formatter (get-formatter
(string-ref format-string
(+ index 2)))))
(if (not formatter)
(time-error 'date-printer
'bad-date-format-string
format-string)
(begin
(formatter date #\Space port)
(date-printer date
(+ index 3)
format-string
str-len
port))))))
(else
(let ((formatter (get-formatter
(string-ref format-string
(+ index 1)))))
(if (not formatter)
(time-error 'date-printer
'bad-date-format-string
format-string)
(begin
(formatter date #\0 port)
(date-printer date
(+ index 2)
format-string
str-len
port))))))))))))
(define (date->string date . format-string)
(let ((str-port (open-output-string))
(fmt-str (if (null? format-string) "~c" (car format-string))))
(date-printer date 0 fmt-str (string-length fmt-str) str-port)
(get-output-string str-port)))
(define (char->int ch)
(case ch
((#\0) 0)
((#\1) 1)
((#\2) 2)
((#\3) 3)
((#\4) 4)
((#\5) 5)
((#\6) 6)
((#\7) 7)
((#\8) 8)
((#\9) 9)
(else (time-error 'char->int 'bad-date-template-string
(list "Non-integer character" ch)))))
;; read an integer upto n characters long on port; upto -> #f is any length
(define (integer-reader upto port)
(let loop ((accum 0) (nchars 0))
(let ((ch (peek-char port)))
(if (or (eof-object? ch)
(not (char-numeric? ch))
(and upto (>= nchars upto)))
accum
(loop (+ (* accum 10) (char->int (read-char port)))
(+ nchars 1))))))
(define (make-integer-reader upto)
(lambda (port)
(integer-reader upto port)))
;; read an fractional integer upto n characters long on port; upto -> #f if any length
;;
;; The return value is normalized to upto decimal places. For example, if upto is 9 and
;; the string read is "123", the return value is 123000000.
(define (fractional-integer-reader upto port)
(define (accum-int port accum nchars)
(let ((ch (peek-char port)))
(if (or (eof-object? ch)
(not (char-numeric? ch))
(and upto (>= nchars upto)))
(* accum (expt 10 (- upto nchars)))
(accum-int port (+ (* accum 10) (char->int (read-char port))) (+ nchars 1)))))
(accum-int port 0 0))
(define (make-fractional-integer-reader upto)
(lambda (port)
(fractional-integer-reader upto port)))
;; read *exactly* n characters and convert to integer; could be padded
(define (integer-reader-exact n port)
(let ((padding-ok #t))
(define (accum-int port accum nchars)
(let ((ch (peek-char port)))
(cond
((>= nchars n) accum)
((eof-object? ch)
(time-error 'string->date 'bad-date-template-string
"Premature ending to integer read."))
((char-numeric? ch)
(set! padding-ok #f)
(accum-int port
(+ (* accum 10) (char->int (read-char port)))
(+ nchars 1)))
(padding-ok
(read-char port) ; consume padding
(accum-int port accum (+ nchars 1)))
(else ; padding where it shouldn't be
(time-error 'string->date 'bad-date-template-string
"Non-numeric characters in integer read.")))))
(accum-int port 0 0)))
(define (make-integer-exact-reader n)
(lambda (port)
(integer-reader-exact n port)))
(define (zone-reader port)
(let ((offset 0)
(positive? #f))
(let ((ch (read-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone +/-" ch)))
(if (or (char=? ch #\Z) (char=? ch #\z))
0
(begin
(cond
((char=? ch #\+) (set! positive? #t))
((char=? ch #\-) (set! positive? #f))
(else
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone +/-" ch))))
(let ((ch (read-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone number" ch)))
(set! offset (* (char->int ch)
10 60 60)))
(let ((ch (read-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone number" ch)))
(set! offset (+ offset (* (char->int ch)
60 60))))
(let ((ch (read-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone number" ch)))
(set! offset (+ offset (* (char->int ch)
10 60))))
(let ((ch (read-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-template-string
(list "Invalid time zone number" ch)))
(set! offset (+ offset (* (char->int ch)
60))))
(if positive? offset (- offset)))))))
;; looking at a char, read the char string, run thru indexer, return index
(define (locale-reader port indexer)
(define (read-char-string result)
(let ((ch (peek-char port)))
(if (char-alphabetic? ch)
(read-char-string (cons (read-char port) result))
(list->string (reverse! result)))))
(let* ((str (read-char-string '()))
(index (indexer str)))
(if index index (time-error 'string->date
'bad-date-template-string
(list "Invalid string for " indexer)))))
(define (make-locale-reader indexer)
(lambda (port)
(locale-reader port indexer)))
(define (make-char-id-reader char)
(lambda (port)
(if (char=? char (read-char port))
char
(time-error 'string->date
'bad-date-template-string
"Invalid character match."))))
;; A List of formatted read directives.
;; Each entry is a list.
;; 1. the character directive;
;; a procedure, which takes a character as input & returns
;; 2. #t as soon as a character on the input port is acceptable
;; for input,
;; 3. a port reader procedure that knows how to read the current port
;; for a value. Its one parameter is the port.
;; 4. an optional action procedure, that takes the value (from 3.) and
;; some object (here, always the date) and (probably) side-effects it.
;; If no action is required, as with ~A, this element may be #f.
(define read-directives
(let ((ireader4 (make-integer-reader 4))
(ireader2 (make-integer-reader 2))
(fireader9 (make-fractional-integer-reader 9))
(eireader2 (make-integer-exact-reader 2))
(locale-reader-abbr-weekday (make-locale-reader
locale-abbr-weekday->index))
(locale-reader-long-weekday (make-locale-reader
locale-long-weekday->index))
(locale-reader-abbr-month (make-locale-reader
locale-abbr-month->index))
(locale-reader-long-month (make-locale-reader
locale-long-month->index))
(char-fail (lambda (ch) #t)))
(list
(list #\~ char-fail (make-char-id-reader #\~) #f)
(list #\a char-alphabetic? locale-reader-abbr-weekday #f)
(list #\A char-alphabetic? locale-reader-long-weekday #f)
(list #\b char-alphabetic? locale-reader-abbr-month
(lambda (val object)
(set-date-month! object val)))
(list #\B char-alphabetic? locale-reader-long-month
(lambda (val object)
(set-date-month! object val)))
(list #\d char-numeric? ireader2 (lambda (val object)
(set-date-day!
object val)))
(list #\e char-fail eireader2 (lambda (val object)
(set-date-day! object val)))
(list #\h char-alphabetic? locale-reader-abbr-month
(lambda (val object)
(set-date-month! object val)))
(list #\H char-numeric? ireader2 (lambda (val object)
(set-date-hour! object val)))
(list #\k char-fail eireader2 (lambda (val object)
(set-date-hour! object val)))
(list #\m char-numeric? ireader2 (lambda (val object)
(set-date-month! object val)))
(list #\M char-numeric? ireader2 (lambda (val object)
(set-date-minute!
object val)))
(list #\N char-numeric? fireader9 (lambda (val object)
(set-date-nanosecond!
object val)))
(list #\S char-numeric? ireader2 (lambda (val object)
(set-date-second! object val)))
(list #\y char-fail eireader2
(lambda (val object)
(set-date-year! object (natural-year val))))
;; XXX FIXME: Support the extended year format used by
;; 'date->string' when the year is not in the range 0-9999.
(list #\Y char-numeric? ireader4 (lambda (val object)
(set-date-year! object val)))
(list #\z (lambda (c)
(or (char=? c #\Z)
(char=? c #\z)
(char=? c #\+)
(char=? c #\-)))
zone-reader (lambda (val object)
(set-date-zone-offset! object val))))))
(define (priv:string->date date index format-string str-len port template-string)
(define (skip-until port skipper)
(let ((ch (peek-char port)))
(if (eof-object? ch)
(time-error 'string->date 'bad-date-format-string template-string)
(if (not (skipper ch))
(begin (read-char port) (skip-until port skipper))))))
(if (< index str-len)
(let ((current-char (string-ref format-string index)))
(if (not (char=? current-char #\~))
(let ((port-char (read-char port)))
(if (or (eof-object? port-char)
(not (char=? current-char port-char)))
(time-error 'string->date
'bad-date-format-string template-string))
(priv:string->date date
(+ index 1)
format-string
str-len
port
template-string))
;; otherwise, it's an escape, we hope
(if (> (+ index 1) str-len)
(time-error 'string->date
'bad-date-format-string template-string)
(let* ((format-char (string-ref format-string (+ index 1)))
(format-info (assoc format-char read-directives)))
(if (not format-info)
(time-error 'string->date
'bad-date-format-string template-string)
(begin
(let ((skipper (cadr format-info))
(reader (caddr format-info))
(actor (cadddr format-info)))
(skip-until port skipper)
(let ((val (reader port)))
(if (eof-object? val)
(time-error 'string->date
'bad-date-format-string
template-string)
(if actor (actor val date))))
(priv:string->date date
(+ index 2)
format-string
str-len
port
template-string))))))))))
(define (string->date input-string template-string)
(define (date-ok? date)
(and (date-nanosecond date)
(date-second date)
(date-minute date)
(date-hour date)
(date-day date)
(date-month date)
(date-year date)
(date-zone-offset date)))
(let ((newdate (make-date 0 0 0 0 #f #f #f #f)))
(priv:string->date newdate
0
template-string
(string-length template-string)
(open-input-string input-string)
template-string)
(if (not (date-zone-offset newdate))
(begin
;; this is necessary to get DST right -- as far as we can
;; get it right (think of the double/missing hour in the
;; night when we are switching between normal time and DST).
(set-date-zone-offset! newdate
(local-tz-offset
(make-time time-utc 0 0)))
(set-date-zone-offset! newdate
(local-tz-offset
(date->time-utc newdate)))))
(if (date-ok? newdate)
newdate
(time-error
'string->date
'bad-date-format-string
(list "Incomplete date read. " newdate template-string)))))
;;; srfi-19.scm ends here
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