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;;; srfi-19.scm --- Time/Date Library
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;; Copyright (C) 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
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;; This library is free software; you can redistribute it and/or
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;; modify it under the terms of the GNU Lesser General Public
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;; License as published by the Free Software Foundation; either
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;; version 2.1 of the License, or (at your option) any later version.
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;; This library is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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;; Lesser General Public License for more details.
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;; You should have received a copy of the GNU Lesser General Public
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;; License along with this library; if not, write to the Free Software
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;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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;;; Author: Rob Browning <rlb@cs.utexas.edu>
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;;; Originally from SRFI reference implementation by Will Fitzgerald.
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;; This module is fully documented in the Guile Reference Manual.
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;; FIXME: I haven't checked a decent amount of this code for potential
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;; performance improvements, but I suspect that there may be some
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;; substantial ones to be realized, esp. in the later "parsing" half
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;; of the file, by rewriting the code with use of more Guile native
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;; functions that do more work in a "chunk".
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;; FIXME: mkoeppe: Time zones are treated a little simplistic in
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;; SRFI-19; they are only a numeric offset. Thus, printing time zones
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;; (PRIV:LOCALE-PRINT-TIME-ZONE) can't be implemented sensibly. The
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;; functions taking an optional TZ-OFFSET should be extended to take a
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;; symbolic time-zone (like "CET"); this string should be stored in
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;; the DATE structure.
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(define-module (srfi srfi-19)
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:use-module (srfi srfi-6)
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:use-module (srfi srfi-8)
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:use-module (srfi srfi-9))
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;; Prevent `export' from re-exporting core bindings. This behaviour
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;; of `export' is deprecated and will disappear in one of the next
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(define current-time #f))
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;; Current time and clock resolution
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current-modified-julian-day
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;; Time object and accessors
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;; Time comparison procedures
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;; Time arithmetic procedures
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;; Date object and accessors
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;; Time/Date/Julian Day/Modified Julian Day converters
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date->modified-julian-day
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julian-day->time-monotonic
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modified-julian-day->date
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modified-julian-day->time-monotonic
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modified-julian-day->time-tai
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modified-julian-day->time-utc
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time-monotonic->time-tai
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time-monotonic->time-tai!
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time-monotonic->time-utc
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time-monotonic->time-utc!
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time-tai->modified-julian-day
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time-tai->time-monotonic
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time-tai->time-monotonic!
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time-utc->modified-julian-day
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time-utc->time-monotonic
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time-utc->time-monotonic!
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;; Date to string/string to date converters.
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(cond-expand-provide (current-module) '(srfi-19))
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(define time-tai 'time-tai)
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(define time-utc 'time-utc)
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(define time-monotonic 'time-monotonic)
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(define time-thread 'time-thread)
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(define time-process 'time-process)
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(define time-duration 'time-duration)
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;; FIXME: do we want to add gc time?
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;; (define time-gc 'time-gc)
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;;-- LOCALE dependent constants
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(define priv:locale-number-separator ".")
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(define priv:locale-abbr-weekday-vector
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(vector "Sun" "Mon" "Tue" "Wed" "Thu" "Fri" "Sat"))
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(define priv:locale-long-weekday-vector
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"Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"))
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;; note empty string in 0th place.
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(define priv:locale-abbr-month-vector
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(define priv:locale-long-month-vector
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(define priv:locale-pm "PM")
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(define priv:locale-am "AM")
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(define priv:locale-date-time-format "~a ~b ~d ~H:~M:~S~z ~Y")
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(define priv:locale-short-date-format "~m/~d/~y")
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(define priv:locale-time-format "~H:~M:~S")
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(define priv:iso-8601-date-time-format "~Y-~m-~dT~H:~M:~S~z")
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;;-- Miscellaneous Constants.
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;;-- only the priv:tai-epoch-in-jd might need changing if
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;; a different epoch is used.
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(define priv:nano 1000000000) ; nanoseconds in a second
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(define priv:sid 86400) ; seconds in a day
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(define priv:sihd 43200) ; seconds in a half day
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(define priv:tai-epoch-in-jd 4881175/2) ; julian day number for 'the epoch'
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;; FIXME: should this be something other than misc-error?
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(define (priv:time-error caller type value)
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(throw 'misc-error caller "TIME-ERROR type ~A: ~S" (list type value) #f)
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(throw 'misc-error caller "TIME-ERROR type ~A" (list type) #f)))
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;; A table of leap seconds
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;; See ftp://maia.usno.navy.mil/ser7/tai-utc.dat
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;; and update as necessary.
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;; this procedures reads the file in the abover
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;; format and creates the leap second table
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;; it also calls the almost standard, but not R5 procedures read-line
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;; & open-input-string
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;; ie (set! priv:leap-second-table (priv:read-tai-utc-date "tai-utc.dat"))
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(define (priv:read-tai-utc-data filename)
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(define (convert-jd jd)
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(* (- (inexact->exact jd) priv:tai-epoch-in-jd) priv:sid))
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(define (convert-sec sec)
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(inexact->exact sec))
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(let ((port (open-input-file filename))
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(let loop ((line (read-line port)))
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(if (not (eq? line eof))
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(let* ((data (read (open-input-string
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(string-append "(" line ")"))))
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(jd (cadddr (cdr data)))
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(secs (cadddr (cdddr data))))
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(cons (convert-jd jd) (convert-sec secs))
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(loop (read-line port))))))
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;; each entry is (tai seconds since epoch . # seconds to subtract for utc)
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;; note they go higher to lower, and end in 1972.
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(define priv:leap-second-table
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(define (read-leap-second-table filename)
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(set! priv:leap-second-table (priv:read-tai-utc-data filename))
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(define (priv:leap-second-delta utc-seconds)
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(letrec ((lsd (lambda (table)
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(cond ((>= utc-seconds (caar table))
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(else (lsd (cdr table)))))))
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(if (< utc-seconds (* (- 1972 1970) 365 priv:sid)) 0
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(lsd priv:leap-second-table))))
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;;; the TIME structure; creates the accessors, too.
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(define-record-type time
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(make-time-unnormalized type nanosecond second)
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(type time-type set-time-type!)
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(nanosecond time-nanosecond set-time-nanosecond!)
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(second time-second set-time-second!))
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(define (copy-time time)
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(make-time (time-type time) (time-nanosecond time) (time-second time)))
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(define (priv:split-real r)
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(values (inexact->exact r) 0)
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(let ((l (truncate r)))
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(values (inexact->exact l) (- r l)))))
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(define (priv:time-normalize! t)
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(if (>= (abs (time-nanosecond t)) 1000000000)
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(priv:split-real (time-nanosecond t))
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(set-time-second! t (+ (time-second t)
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(quotient int 1000000000)))
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(set-time-nanosecond! t (+ (remainder int 1000000000)
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(if (and (positive? (time-second t))
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(negative? (time-nanosecond t)))
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(set-time-second! t (- (time-second t) 1))
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(set-time-nanosecond! t (+ 1000000000 (time-nanosecond t))))
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(if (and (negative? (time-second t))
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(positive? (time-nanosecond t)))
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(set-time-second! t (+ (time-second t) 1))
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(set-time-nanosecond! t (+ 1000000000 (time-nanosecond t))))))
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(define (make-time type nanosecond second)
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(priv:time-normalize! (make-time-unnormalized type nanosecond second)))
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;; FIXME: finish this and publish it?
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(define (date->broken-down-time date)
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(let ((result (mktime 0)))
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;; FIXME: What should we do about leap-seconds which may overflow
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(set-tm:sec result (date-second date))
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(set-tm:min result (date-minute date))
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(set-tm:hour result (date-hour date))
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;; FIXME: SRFI day ranges from 0-31. (not compatible with set-tm:mday).
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(set-tm:mday result (date-day date))
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(set-tm:month result (- (date-month date) 1))
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;; FIXME: need to signal error on range violation.
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(set-tm:year result (+ 1900 (date-year date)))
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(set-tm:isdst result -1)
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(set-tm:gmtoff result (- (date-zone-offset date)))
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;;; specific time getters.
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(define (priv:current-time-utc)
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;; Resolution is microseconds.
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(let ((tod (gettimeofday)))
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(make-time time-utc (* (cdr tod) 1000) (car tod))))
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(define (priv:current-time-tai)
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;; Resolution is microseconds.
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(let* ((tod (gettimeofday))
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(+ (car tod) (priv:leap-second-delta sec)))))
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;;(define (priv:current-time-ms-time time-type proc)
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;; (let ((current-ms (proc)))
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;; (make-time time-type
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;; (quotient current-ms 10000)
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;; (* (remainder current-ms 1000) 10000))))
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;; -- we define it to be the same as TAI.
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;; A different implemation of current-time-montonic
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;; will require rewriting all of the time-monotonic converters,
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(define (priv:current-time-monotonic)
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;; Resolution is microseconds.
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(priv:current-time-tai))
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(define (priv:current-time-thread)
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(priv:time-error 'current-time 'unsupported-clock-type 'time-thread))
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(define priv:ns-per-guile-tick (/ 1000000000 internal-time-units-per-second))
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(define (priv:current-time-process)
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(let ((run-time (get-internal-run-time)))
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(quotient run-time internal-time-units-per-second)
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(* (remainder run-time internal-time-units-per-second)
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priv:ns-per-guile-tick))))
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(define (priv:current-time-process)
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(let ((run-time (get-internal-run-time)))
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(* (remainder run-time internal-time-units-per-second)
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priv:ns-per-guile-tick)
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(quotient run-time internal-time-units-per-second))))
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;;(define (priv:current-time-gc)
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;; (priv:current-time-ms-time time-gc current-gc-milliseconds))
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(define (current-time . clock-type)
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(let ((clock-type (if (null? clock-type) time-utc (car clock-type))))
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((eq? clock-type time-tai) (priv:current-time-tai))
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((eq? clock-type time-utc) (priv:current-time-utc))
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((eq? clock-type time-monotonic) (priv:current-time-monotonic))
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((eq? clock-type time-thread) (priv:current-time-thread))
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((eq? clock-type time-process) (priv:current-time-process))
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;; ((eq? clock-type time-gc) (priv:current-time-gc))
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(else (priv:time-error 'current-time 'invalid-clock-type clock-type)))))
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;; -- Time Resolution
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;; This is the resolution of the clock in nanoseconds.
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;; This will be implementation specific.
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(define (time-resolution . clock-type)
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(let ((clock-type (if (null? clock-type) time-utc (car clock-type))))
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((time-monotonic) 1000)
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((time-process) priv:ns-per-guile-tick)
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;; ((eq? clock-type time-thread) 1000)
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;; ((eq? clock-type time-gc) 10000)
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(else (priv:time-error 'time-resolution 'invalid-clock-type clock-type)))))
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;; -- Time comparisons
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(define (time=? t1 t2)
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;; Arrange tests for speed and presume that t1 and t2 are actually times.
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;; also presume it will be rare to check two times of different types.
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(and (= (time-second t1) (time-second t2))
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(= (time-nanosecond t1) (time-nanosecond t2))
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(eq? (time-type t1) (time-type t2))))
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(define (time>? t1 t2)
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(or (> (time-second t1) (time-second t2))
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(and (= (time-second t1) (time-second t2))
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(> (time-nanosecond t1) (time-nanosecond t2)))))
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(define (time<? t1 t2)
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(or (< (time-second t1) (time-second t2))
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(and (= (time-second t1) (time-second t2))
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(< (time-nanosecond t1) (time-nanosecond t2)))))
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(define (time>=? t1 t2)
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(or (> (time-second t1) (time-second t2))
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(and (= (time-second t1) (time-second t2))
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(>= (time-nanosecond t1) (time-nanosecond t2)))))
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(define (time<=? t1 t2)
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(or (< (time-second t1) (time-second t2))
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(and (= (time-second t1) (time-second t2))
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(<= (time-nanosecond t1) (time-nanosecond t2)))))
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;; -- Time arithmetic
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(define (time-difference! time1 time2)
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(let ((sec-diff (- (time-second time1) (time-second time2)))
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(nsec-diff (- (time-nanosecond time1) (time-nanosecond time2))))
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(set-time-type! time1 time-duration)
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(set-time-second! time1 sec-diff)
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(set-time-nanosecond! time1 nsec-diff)
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(priv:time-normalize! time1)))
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(define (time-difference time1 time2)
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(let ((result (copy-time time1)))
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(time-difference! result time2)))
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(define (add-duration! t duration)
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(if (not (eq? (time-type duration) time-duration))
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(priv:time-error 'add-duration 'not-duration duration)
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(let ((sec-plus (+ (time-second t) (time-second duration)))
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(nsec-plus (+ (time-nanosecond t) (time-nanosecond duration))))
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(set-time-second! t sec-plus)
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(set-time-nanosecond! t nsec-plus)
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(priv:time-normalize! t))))
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(define (add-duration t duration)
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(let ((result (copy-time t)))
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(add-duration! result duration)))
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(define (subtract-duration! t duration)
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(if (not (eq? (time-type duration) time-duration))
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(priv:time-error 'add-duration 'not-duration duration)
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(let ((sec-minus (- (time-second t) (time-second duration)))
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(nsec-minus (- (time-nanosecond t) (time-nanosecond duration))))
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(set-time-second! t sec-minus)
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(set-time-nanosecond! t nsec-minus)
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(priv:time-normalize! t))))
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(define (subtract-duration time1 duration)
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(let ((result (copy-time time1)))
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(subtract-duration! result duration)))
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;; -- Converters between types.
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(define (priv:time-tai->time-utc! time-in time-out caller)
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(if (not (eq? (time-type time-in) time-tai))
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(priv:time-error caller 'incompatible-time-types time-in))
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(set-time-type! time-out time-utc)
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(set-time-nanosecond! time-out (time-nanosecond time-in))
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(set-time-second! time-out (- (time-second time-in)
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(priv:leap-second-delta
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(time-second time-in))))
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(define (time-tai->time-utc time-in)
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(priv:time-tai->time-utc! time-in (make-time-unnormalized #f #f #f) 'time-tai->time-utc))
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(define (time-tai->time-utc! time-in)
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(priv:time-tai->time-utc! time-in time-in 'time-tai->time-utc!))
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(define (priv:time-utc->time-tai! time-in time-out caller)
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(if (not (eq? (time-type time-in) time-utc))
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(priv:time-error caller 'incompatible-time-types time-in))
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(set-time-type! time-out time-tai)
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(set-time-nanosecond! time-out (time-nanosecond time-in))
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(set-time-second! time-out (+ (time-second time-in)
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(priv:leap-second-delta
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(time-second time-in))))
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(define (time-utc->time-tai time-in)
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(priv:time-utc->time-tai! time-in (make-time-unnormalized #f #f #f) 'time-utc->time-tai))
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(define (time-utc->time-tai! time-in)
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(priv:time-utc->time-tai! time-in time-in 'time-utc->time-tai!))
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;; -- these depend on time-monotonic having the same definition as time-tai!
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(define (time-monotonic->time-utc time-in)
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(if (not (eq? (time-type time-in) time-monotonic))
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(priv:time-error caller 'incompatible-time-types time-in))
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(let ((ntime (copy-time time-in)))
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(set-time-type! ntime time-tai)
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(priv:time-tai->time-utc! ntime ntime 'time-monotonic->time-utc)))
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(define (time-monotonic->time-utc! time-in)
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(if (not (eq? (time-type time-in) time-monotonic))
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(priv:time-error caller 'incompatible-time-types time-in))
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(set-time-type! time-in time-tai)
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(priv:time-tai->time-utc! ntime ntime 'time-monotonic->time-utc))
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(define (time-monotonic->time-tai time-in)
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(if (not (eq? (time-type time-in) time-monotonic))
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(priv:time-error caller 'incompatible-time-types time-in))
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(let ((ntime (copy-time time-in)))
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(set-time-type! ntime time-tai)
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(define (time-monotonic->time-tai! time-in)
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(if (not (eq? (time-type time-in) time-monotonic))
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(priv:time-error caller 'incompatible-time-types time-in))
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(set-time-type! time-in time-tai)
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(define (time-utc->time-monotonic time-in)
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(if (not (eq? (time-type time-in) time-utc))
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(priv:time-error caller 'incompatible-time-types time-in))
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(let ((ntime (priv:time-utc->time-tai! time-in (make-time-unnormalized #f #f #f)
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'time-utc->time-monotonic)))
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(set-time-type! ntime time-monotonic)
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(define (time-utc->time-monotonic! time-in)
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(if (not (eq? (time-type time-in) time-utc))
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(priv:time-error caller 'incompatible-time-types time-in))
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(let ((ntime (priv:time-utc->time-tai! time-in time-in
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'time-utc->time-monotonic!)))
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(set-time-type! ntime time-monotonic)
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(define (time-tai->time-monotonic time-in)
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(if (not (eq? (time-type time-in) time-tai))
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(priv:time-error caller 'incompatible-time-types time-in))
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(let ((ntime (copy-time time-in)))
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(set-time-type! ntime time-monotonic)
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(define (time-tai->time-monotonic! time-in)
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(if (not (eq? (time-type time-in) time-tai))
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(priv:time-error caller 'incompatible-time-types time-in))
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(set-time-type! time-in time-monotonic)
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;; -- Date Structures
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;; FIXME: to be really safe, perhaps we should normalize the
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;; seconds/nanoseconds/minutes coming in to make-date...
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(define-record-type date
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(make-date nanosecond second minute
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(nanosecond date-nanosecond set-date-nanosecond!)
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(second date-second set-date-second!)
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(minute date-minute set-date-minute!)
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(hour date-hour set-date-hour!)
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(day date-day set-date-day!)
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(month date-month set-date-month!)
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(year date-year set-date-year!)
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(zone-offset date-zone-offset set-date-zone-offset!))
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;; gives the julian day which starts at noon.
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(define (priv:encode-julian-day-number day month year)
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(let* ((a (quotient (- 14 month) 12))
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(y (- (+ year 4800) a (if (negative? year) -1 0)))
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(m (- (+ month (* 12 a)) 3)))
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(quotient (+ (* 153 m) 2) 5)
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;; gives the seconds/date/month/year
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(define (priv:decode-julian-day-number jdn)
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(let* ((days (inexact->exact (truncate jdn)))
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(b (quotient (+ (* 4 a) 3) 146097))
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(c (- a (quotient (* 146097 b) 4)))
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(d (quotient (+ (* 4 c) 3) 1461))
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(e (- c (quotient (* 1461 d) 4)))
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(m (quotient (+ (* 5 e) 2) 153))
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(y (+ (* 100 b) d -4800 (quotient m 10))))
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(values ; seconds date month year
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(* (- jdn days) priv:sid)
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(+ e (- (quotient (+ (* 153 m) 2) 5)) 1)
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(+ m 3 (* -12 (quotient m 10)))
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(if (>= 0 y) (- y 1) y))))
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;; relies on the fact that we named our time zone accessor
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;; differently from MzScheme's....
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;; This should be written to be OS specific.
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(define (priv:local-tz-offset utc-time)
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;; SRFI uses seconds West, but guile (and libc) use seconds East.
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(- (tm:gmtoff (localtime (time-second utc-time)))))
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;; special thing -- ignores nanos
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(define (priv:time->julian-day-number seconds tz-offset)
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(+ (/ (+ seconds tz-offset priv:sihd)
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priv:tai-epoch-in-jd))
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(define (priv:leap-second? second)
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(and (assoc second priv:leap-second-table) #t))
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(define (time-utc->date time . tz-offset)
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(if (not (eq? (time-type time) time-utc))
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(priv:time-error 'time->date 'incompatible-time-types time))
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(let* ((offset (if (null? tz-offset)
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(priv:local-tz-offset time)
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(leap-second? (priv:leap-second? (+ offset (time-second time))))
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(jdn (priv:time->julian-day-number (if leap-second?
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(- (time-second time) 1)
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(call-with-values (lambda () (priv:decode-julian-day-number jdn))
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(lambda (secs date month year)
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;; secs is a real because jdn is a real in Guile;
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;; but it is conceptionally an integer.
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(let* ((int-secs (inexact->exact (round secs)))
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(hours (quotient int-secs (* 60 60)))
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(rem (remainder int-secs (* 60 60)))
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(minutes (quotient rem 60))
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(seconds (remainder rem 60)))
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(make-date (time-nanosecond time)
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(if leap-second? (+ seconds 1) seconds)
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(define (time-tai->date time . tz-offset)
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(if (not (eq? (time-type time) time-tai))
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(priv:time-error 'time->date 'incompatible-time-types time))
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(let* ((offset (if (null? tz-offset)
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(priv:local-tz-offset (time-tai->time-utc time))
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(seconds (- (time-second time)
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(priv:leap-second-delta (time-second time))))
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(leap-second? (priv:leap-second? (+ offset seconds)))
697
(jdn (priv:time->julian-day-number (if leap-second?
701
(call-with-values (lambda () (priv:decode-julian-day-number jdn))
702
(lambda (secs date month year)
703
;; secs is a real because jdn is a real in Guile;
704
;; but it is conceptionally an integer.
705
;; adjust for leap seconds if necessary ...
706
(let* ((int-secs (inexact->exact (round secs)))
707
(hours (quotient int-secs (* 60 60)))
708
(rem (remainder int-secs (* 60 60)))
709
(minutes (quotient rem 60))
710
(seconds (remainder rem 60)))
711
(make-date (time-nanosecond time)
712
(if leap-second? (+ seconds 1) seconds)
720
;; this is the same as time-tai->date.
721
(define (time-monotonic->date time . tz-offset)
722
(if (not (eq? (time-type time) time-monotonic))
723
(priv:time-error 'time->date 'incompatible-time-types time))
724
(let* ((offset (if (null? tz-offset)
725
(priv:local-tz-offset (time-monotonic->time-utc time))
727
(seconds (- (time-second time)
728
(priv:leap-second-delta (time-second time))))
729
(leap-second? (priv:leap-second? (+ offset seconds)))
730
(jdn (priv:time->julian-day-number (if leap-second?
734
(call-with-values (lambda () (priv:decode-julian-day-number jdn))
735
(lambda (secs date month year)
736
;; secs is a real because jdn is a real in Guile;
737
;; but it is conceptionally an integer.
738
;; adjust for leap seconds if necessary ...
739
(let* ((int-secs (inexact->exact (round secs)))
740
(hours (quotient int-secs (* 60 60)))
741
(rem (remainder int-secs (* 60 60)))
742
(minutes (quotient rem 60))
743
(seconds (remainder rem 60)))
744
(make-date (time-nanosecond time)
745
(if leap-second? (+ seconds 1) seconds)
753
(define (date->time-utc date)
754
(let* ((jdays (- (priv:encode-julian-day-number (date-day date)
757
priv:tai-epoch-in-jd))
758
;; jdays is an integer plus 1/2,
759
(jdays-1/2 (inexact->exact (- jdays 1/2))))
762
(date-nanosecond date)
763
(+ (* jdays-1/2 24 60 60)
764
(* (date-hour date) 60 60)
765
(* (date-minute date) 60)
767
(- (date-zone-offset date))))))
769
(define (date->time-tai date)
770
(time-utc->time-tai! (date->time-utc date)))
772
(define (date->time-monotonic date)
773
(time-utc->time-monotonic! (date->time-utc date)))
775
(define (priv:leap-year? year)
776
(or (= (modulo year 400) 0)
777
(and (= (modulo year 4) 0) (not (= (modulo year 100) 0)))))
779
(define (leap-year? date)
780
(priv:leap-year? (date-year date)))
782
;; Map 1-based month number M to number of days in the year before the
783
;; start of month M (in a non-leap year).
784
(define priv:month-assoc '((1 . 0) (2 . 31) (3 . 59) (4 . 90)
785
(5 . 120) (6 . 151) (7 . 181) (8 . 212)
786
(9 . 243) (10 . 273) (11 . 304) (12 . 334)))
788
(define (priv:year-day day month year)
789
(let ((days-pr (assoc month priv:month-assoc)))
791
(priv:error 'date-year-day 'invalid-month-specification month))
792
(if (and (priv:leap-year? year) (> month 2))
793
(+ day (cdr days-pr) 1)
794
(+ day (cdr days-pr)))))
796
(define (date-year-day date)
797
(priv:year-day (date-day date) (date-month date) (date-year date)))
800
(define (priv:week-day day month year)
801
(let* ((a (quotient (- 14 month) 12))
803
(m (+ month (* 12 a) -2)))
809
(quotient (* 31 m) 12))
812
(define (date-week-day date)
813
(priv:week-day (date-day date) (date-month date) (date-year date)))
815
(define (priv:days-before-first-week date day-of-week-starting-week)
816
(let* ((first-day (make-date 0 0 0 0
821
(fdweek-day (date-week-day first-day)))
822
(modulo (- day-of-week-starting-week fdweek-day)
825
;; The "-1" here is a fix for the reference implementation, to make a new
826
;; week start on the given day-of-week-starting-week. date-year-day returns
827
;; a day starting from 1 for 1st Jan.
829
(define (date-week-number date day-of-week-starting-week)
830
(quotient (- (date-year-day date)
832
(priv:days-before-first-week date day-of-week-starting-week))
835
(define (current-date . tz-offset)
836
(let ((time (current-time time-utc)))
839
(if (null? tz-offset)
840
(priv:local-tz-offset time)
843
;; given a 'two digit' number, find the year within 50 years +/-
844
(define (priv:natural-year n)
845
(let* ((current-year (date-year (current-date)))
846
(current-century (* (quotient current-year 100) 100)))
850
((<= (- (+ current-century n) current-year) 50) (+ current-century n))
851
(else (+ (- current-century 100) n)))))
853
(define (date->julian-day date)
854
(let ((nanosecond (date-nanosecond date))
855
(second (date-second date))
856
(minute (date-minute date))
857
(hour (date-hour date))
858
(day (date-day date))
859
(month (date-month date))
860
(year (date-year date)))
861
(+ (priv:encode-julian-day-number day month year)
863
(+ (/ (+ (* hour 60 60)
866
(/ nanosecond priv:nano))
869
(define (date->modified-julian-day date)
870
(- (date->julian-day date)
873
(define (time-utc->julian-day time)
874
(if (not (eq? (time-type time) time-utc))
875
(priv:time-error 'time->date 'incompatible-time-types time))
876
(+ (/ (+ (time-second time) (/ (time-nanosecond time) priv:nano))
878
priv:tai-epoch-in-jd))
880
(define (time-utc->modified-julian-day time)
881
(- (time-utc->julian-day time)
884
(define (time-tai->julian-day time)
885
(if (not (eq? (time-type time) time-tai))
886
(priv:time-error 'time->date 'incompatible-time-types time))
887
(+ (/ (+ (- (time-second time)
888
(priv:leap-second-delta (time-second time)))
889
(/ (time-nanosecond time) priv:nano))
891
priv:tai-epoch-in-jd))
893
(define (time-tai->modified-julian-day time)
894
(- (time-tai->julian-day time)
897
;; this is the same as time-tai->julian-day
898
(define (time-monotonic->julian-day time)
899
(if (not (eq? (time-type time) time-monotonic))
900
(priv:time-error 'time->date 'incompatible-time-types time))
901
(+ (/ (+ (- (time-second time)
902
(priv:leap-second-delta (time-second time)))
903
(/ (time-nanosecond time) priv:nano))
905
priv:tai-epoch-in-jd))
907
(define (time-monotonic->modified-julian-day time)
908
(- (time-monotonic->julian-day time)
911
(define (julian-day->time-utc jdn)
912
(let ((secs (* priv:sid (- jdn priv:tai-epoch-in-jd))))
913
(receive (seconds parts)
914
(priv:split-real secs)
919
(define (julian-day->time-tai jdn)
920
(time-utc->time-tai! (julian-day->time-utc jdn)))
922
(define (julian-day->time-monotonic jdn)
923
(time-utc->time-monotonic! (julian-day->time-utc jdn)))
925
(define (julian-day->date jdn . tz-offset)
926
(let* ((time (julian-day->time-utc jdn))
927
(offset (if (null? tz-offset)
928
(priv:local-tz-offset time)
930
(time-utc->date time offset)))
932
(define (modified-julian-day->date jdn . tz-offset)
933
(apply julian-day->date (+ jdn 4800001/2)
936
(define (modified-julian-day->time-utc jdn)
937
(julian-day->time-utc (+ jdn 4800001/2)))
939
(define (modified-julian-day->time-tai jdn)
940
(julian-day->time-tai (+ jdn 4800001/2)))
942
(define (modified-julian-day->time-monotonic jdn)
943
(julian-day->time-monotonic (+ jdn 4800001/2)))
945
(define (current-julian-day)
946
(time-utc->julian-day (current-time time-utc)))
948
(define (current-modified-julian-day)
949
(time-utc->modified-julian-day (current-time time-utc)))
951
;; returns a string rep. of number N, of minimum LENGTH, padded with
952
;; character PAD-WITH. If PAD-WITH is #f, no padding is done, and it's
953
;; as if number->string was used. if string is longer than or equal
954
;; in length to LENGTH, it's as if number->string was used.
956
(define (priv:padding n pad-with length)
957
(let* ((str (number->string n))
958
(str-len (string-length str)))
959
(if (or (>= str-len length)
962
(string-append (make-string (- length str-len) pad-with) str))))
964
(define (priv:last-n-digits i n)
965
(abs (remainder i (expt 10 n))))
967
(define (priv:locale-abbr-weekday n)
968
(vector-ref priv:locale-abbr-weekday-vector n))
970
(define (priv:locale-long-weekday n)
971
(vector-ref priv:locale-long-weekday-vector n))
973
(define (priv:locale-abbr-month n)
974
(vector-ref priv:locale-abbr-month-vector n))
976
(define (priv:locale-long-month n)
977
(vector-ref priv:locale-long-month-vector n))
979
(define (priv:vector-find needle haystack comparator)
980
(let ((len (vector-length haystack)))
981
(define (priv:vector-find-int index)
984
((comparator needle (vector-ref haystack index)) index)
985
(else (priv:vector-find-int (+ index 1)))))
986
(priv:vector-find-int 0)))
988
(define (priv:locale-abbr-weekday->index string)
989
(priv:vector-find string priv:locale-abbr-weekday-vector string=?))
991
(define (priv:locale-long-weekday->index string)
992
(priv:vector-find string priv:locale-long-weekday-vector string=?))
994
(define (priv:locale-abbr-month->index string)
995
(priv:vector-find string priv:locale-abbr-month-vector string=?))
997
(define (priv:locale-long-month->index string)
998
(priv:vector-find string priv:locale-long-month-vector string=?))
1001
;; FIXME: mkoeppe: Put a symbolic time zone in the date structs.
1002
;; Print it here instead of the numerical offset if available.
1003
(define (priv:locale-print-time-zone date port)
1004
(priv:tz-printer (date-zone-offset date) port))
1006
;; FIXME: we should use strftime to determine this dynamically if possible.
1007
;; Again, locale specific.
1008
(define (priv:locale-am/pm hr)
1009
(if (> hr 11) priv:locale-pm priv:locale-am))
1011
(define (priv:tz-printer offset port)
1013
((= offset 0) (display "Z" port))
1014
((negative? offset) (display "-" port))
1015
(else (display "+" port)))
1016
(if (not (= offset 0))
1017
(let ((hours (abs (quotient offset (* 60 60))))
1018
(minutes (abs (quotient (remainder offset (* 60 60)) 60))))
1019
(display (priv:padding hours #\0 2) port)
1020
(display (priv:padding minutes #\0 2) port))))
1022
;; A table of output formatting directives.
1023
;; the first time is the format char.
1024
;; the second is a procedure that takes the date, a padding character
1025
;; (which might be #f), and the output port.
1027
(define priv:directives
1029
(cons #\~ (lambda (date pad-with port)
1030
(display #\~ port)))
1031
(cons #\a (lambda (date pad-with port)
1032
(display (priv:locale-abbr-weekday (date-week-day date))
1034
(cons #\A (lambda (date pad-with port)
1035
(display (priv:locale-long-weekday (date-week-day date))
1037
(cons #\b (lambda (date pad-with port)
1038
(display (priv:locale-abbr-month (date-month date))
1040
(cons #\B (lambda (date pad-with port)
1041
(display (priv:locale-long-month (date-month date))
1043
(cons #\c (lambda (date pad-with port)
1044
(display (date->string date priv:locale-date-time-format) port)))
1045
(cons #\d (lambda (date pad-with port)
1046
(display (priv:padding (date-day date)
1049
(cons #\D (lambda (date pad-with port)
1050
(display (date->string date "~m/~d/~y") port)))
1051
(cons #\e (lambda (date pad-with port)
1052
(display (priv:padding (date-day date)
1055
(cons #\f (lambda (date pad-with port)
1056
(if (> (date-nanosecond date)
1058
(display (priv:padding (+ (date-second date) 1)
1061
(display (priv:padding (date-second date)
1066
(date-nanosecond date)
1068
(let* ((ns (number->string f))
1069
(le (string-length ns)))
1072
(display priv:locale-number-separator port)
1073
(display (substring ns 2 le) port)))))))
1074
(cons #\h (lambda (date pad-with port)
1075
(display (date->string date "~b") port)))
1076
(cons #\H (lambda (date pad-with port)
1077
(display (priv:padding (date-hour date)
1080
(cons #\I (lambda (date pad-with port)
1081
(let ((hr (date-hour date)))
1083
(display (priv:padding (- hr 12)
1086
(display (priv:padding hr
1089
(cons #\j (lambda (date pad-with port)
1090
(display (priv:padding (date-year-day date)
1093
(cons #\k (lambda (date pad-with port)
1094
(display (priv:padding (date-hour date)
1097
(cons #\l (lambda (date pad-with port)
1098
(let ((hr (if (> (date-hour date) 12)
1099
(- (date-hour date) 12) (date-hour date))))
1100
(display (priv:padding hr #\Space 2)
1102
(cons #\m (lambda (date pad-with port)
1103
(display (priv:padding (date-month date)
1106
(cons #\M (lambda (date pad-with port)
1107
(display (priv:padding (date-minute date)
1110
(cons #\n (lambda (date pad-with port)
1112
(cons #\N (lambda (date pad-with port)
1113
(display (priv:padding (date-nanosecond date)
1116
(cons #\p (lambda (date pad-with port)
1117
(display (priv:locale-am/pm (date-hour date)) port)))
1118
(cons #\r (lambda (date pad-with port)
1119
(display (date->string date "~I:~M:~S ~p") port)))
1120
(cons #\s (lambda (date pad-with port)
1121
(display (time-second (date->time-utc date)) port)))
1122
(cons #\S (lambda (date pad-with port)
1123
(if (> (date-nanosecond date)
1125
(display (priv:padding (+ (date-second date) 1)
1128
(display (priv:padding (date-second date)
1131
(cons #\t (lambda (date pad-with port)
1132
(display #\Tab port)))
1133
(cons #\T (lambda (date pad-with port)
1134
(display (date->string date "~H:~M:~S") port)))
1135
(cons #\U (lambda (date pad-with port)
1136
(if (> (priv:days-before-first-week date 0) 0)
1137
(display (priv:padding (+ (date-week-number date 0) 1)
1139
(display (priv:padding (date-week-number date 0)
1141
(cons #\V (lambda (date pad-with port)
1142
(display (priv:padding (date-week-number date 1)
1144
(cons #\w (lambda (date pad-with port)
1145
(display (date-week-day date) port)))
1146
(cons #\x (lambda (date pad-with port)
1147
(display (date->string date priv:locale-short-date-format) port)))
1148
(cons #\X (lambda (date pad-with port)
1149
(display (date->string date priv:locale-time-format) port)))
1150
(cons #\W (lambda (date pad-with port)
1151
(if (> (priv:days-before-first-week date 1) 0)
1152
(display (priv:padding (+ (date-week-number date 1) 1)
1154
(display (priv:padding (date-week-number date 1)
1156
(cons #\y (lambda (date pad-with port)
1157
(display (priv:padding (priv:last-n-digits
1162
(cons #\Y (lambda (date pad-with port)
1163
(display (date-year date) port)))
1164
(cons #\z (lambda (date pad-with port)
1165
(priv:tz-printer (date-zone-offset date) port)))
1166
(cons #\Z (lambda (date pad-with port)
1167
(priv:locale-print-time-zone date port)))
1168
(cons #\1 (lambda (date pad-with port)
1169
(display (date->string date "~Y-~m-~d") port)))
1170
(cons #\2 (lambda (date pad-with port)
1171
(display (date->string date "~k:~M:~S~z") port)))
1172
(cons #\3 (lambda (date pad-with port)
1173
(display (date->string date "~k:~M:~S") port)))
1174
(cons #\4 (lambda (date pad-with port)
1175
(display (date->string date "~Y-~m-~dT~k:~M:~S~z") port)))
1176
(cons #\5 (lambda (date pad-with port)
1177
(display (date->string date "~Y-~m-~dT~k:~M:~S") port)))))
1180
(define (priv:get-formatter char)
1181
(let ((associated (assoc char priv:directives)))
1182
(if associated (cdr associated) #f)))
1184
(define (priv:date-printer date index format-string str-len port)
1185
(if (>= index str-len)
1187
(let ((current-char (string-ref format-string index)))
1188
(if (not (char=? current-char #\~))
1190
(display current-char port)
1191
(priv:date-printer date (+ index 1) format-string str-len port))
1192
(if (= (+ index 1) str-len) ; bad format string.
1193
(priv:time-error 'priv:date-printer 'bad-date-format-string
1195
(let ((pad-char? (string-ref format-string (+ index 1))))
1197
((char=? pad-char? #\-)
1198
(if (= (+ index 2) str-len) ; bad format string.
1199
(priv:time-error 'priv:date-printer
1200
'bad-date-format-string
1202
(let ((formatter (priv:get-formatter
1203
(string-ref format-string
1206
(priv:time-error 'priv:date-printer
1207
'bad-date-format-string
1210
(formatter date #f port)
1211
(priv:date-printer date
1217
((char=? pad-char? #\_)
1218
(if (= (+ index 2) str-len) ; bad format string.
1219
(priv:time-error 'priv:date-printer
1220
'bad-date-format-string
1222
(let ((formatter (priv:get-formatter
1223
(string-ref format-string
1226
(priv:time-error 'priv:date-printer
1227
'bad-date-format-string
1230
(formatter date #\Space port)
1231
(priv:date-printer date
1237
(let ((formatter (priv:get-formatter
1238
(string-ref format-string
1241
(priv:time-error 'priv:date-printer
1242
'bad-date-format-string
1245
(formatter date #\0 port)
1246
(priv:date-printer date
1253
(define (date->string date . format-string)
1254
(let ((str-port (open-output-string))
1255
(fmt-str (if (null? format-string) "~c" (car format-string))))
1256
(priv:date-printer date 0 fmt-str (string-length fmt-str) str-port)
1257
(get-output-string str-port)))
1259
(define (priv:char->int ch)
1271
(else (priv:time-error 'bad-date-template-string
1272
(list "Non-integer character" ch i)))))
1274
;; read an integer upto n characters long on port; upto -> #f is any length
1275
(define (priv:integer-reader upto port)
1276
(let loop ((accum 0) (nchars 0))
1277
(let ((ch (peek-char port)))
1278
(if (or (eof-object? ch)
1279
(not (char-numeric? ch))
1280
(and upto (>= nchars upto)))
1282
(loop (+ (* accum 10) (priv:char->int (read-char port)))
1285
(define (priv:make-integer-reader upto)
1287
(priv:integer-reader upto port)))
1289
;; read *exactly* n characters and convert to integer; could be padded
1290
(define (priv:integer-reader-exact n port)
1291
(let ((padding-ok #t))
1292
(define (accum-int port accum nchars)
1293
(let ((ch (peek-char port)))
1295
((>= nchars n) accum)
1297
(priv:time-error 'string->date 'bad-date-template-string
1298
"Premature ending to integer read."))
1300
(set! padding-ok #f)
1302
(+ (* accum 10) (priv:char->int (read-char port)))
1305
(read-char port) ; consume padding
1306
(accum-int port accum (+ nchars 1)))
1307
(else ; padding where it shouldn't be
1308
(priv:time-error 'string->date 'bad-date-template-string
1309
"Non-numeric characters in integer read.")))))
1310
(accum-int port 0 0)))
1313
(define (priv:make-integer-exact-reader n)
1315
(priv:integer-reader-exact n port)))
1317
(define (priv:zone-reader port)
1320
(let ((ch (read-char port)))
1321
(if (eof-object? ch)
1322
(priv:time-error 'string->date 'bad-date-template-string
1323
(list "Invalid time zone +/-" ch)))
1324
(if (or (char=? ch #\Z) (char=? ch #\z))
1328
((char=? ch #\+) (set! positive? #t))
1329
((char=? ch #\-) (set! positive? #f))
1331
(priv:time-error 'string->date 'bad-date-template-string
1332
(list "Invalid time zone +/-" ch))))
1333
(let ((ch (read-char port)))
1334
(if (eof-object? ch)
1335
(priv:time-error 'string->date 'bad-date-template-string
1336
(list "Invalid time zone number" ch)))
1337
(set! offset (* (priv:char->int ch)
1339
(let ((ch (read-char port)))
1340
(if (eof-object? ch)
1341
(priv:time-error 'string->date 'bad-date-template-string
1342
(list "Invalid time zone number" ch)))
1343
(set! offset (+ offset (* (priv:char->int ch)
1345
(let ((ch (read-char port)))
1346
(if (eof-object? ch)
1347
(priv:time-error 'string->date 'bad-date-template-string
1348
(list "Invalid time zone number" ch)))
1349
(set! offset (+ offset (* (priv:char->int ch)
1351
(let ((ch (read-char port)))
1352
(if (eof-object? ch)
1353
(priv:time-error 'string->date 'bad-date-template-string
1354
(list "Invalid time zone number" ch)))
1355
(set! offset (+ offset (* (priv:char->int ch)
1357
(if positive? offset (- offset)))))))
1359
;; looking at a char, read the char string, run thru indexer, return index
1360
(define (priv:locale-reader port indexer)
1362
(define (read-char-string result)
1363
(let ((ch (peek-char port)))
1364
(if (char-alphabetic? ch)
1365
(read-char-string (cons (read-char port) result))
1366
(list->string (reverse! result)))))
1368
(let* ((str (read-char-string '()))
1369
(index (indexer str)))
1370
(if index index (priv:time-error 'string->date
1371
'bad-date-template-string
1372
(list "Invalid string for " indexer)))))
1374
(define (priv:make-locale-reader indexer)
1376
(priv:locale-reader port indexer)))
1378
(define (priv:make-char-id-reader char)
1380
(if (char=? char (read-char port))
1382
(priv:time-error 'string->date
1383
'bad-date-template-string
1384
"Invalid character match."))))
1386
;; A List of formatted read directives.
1387
;; Each entry is a list.
1388
;; 1. the character directive;
1389
;; a procedure, which takes a character as input & returns
1390
;; 2. #t as soon as a character on the input port is acceptable
1392
;; 3. a port reader procedure that knows how to read the current port
1393
;; for a value. Its one parameter is the port.
1394
;; 4. a action procedure, that takes the value (from 3.) and some
1395
;; object (here, always the date) and (probably) side-effects it.
1396
;; In some cases (e.g., ~A) the action is to do nothing
1398
(define priv:read-directives
1399
(let ((ireader4 (priv:make-integer-reader 4))
1400
(ireader2 (priv:make-integer-reader 2))
1401
(ireaderf (priv:make-integer-reader #f))
1402
(eireader2 (priv:make-integer-exact-reader 2))
1403
(eireader4 (priv:make-integer-exact-reader 4))
1404
(locale-reader-abbr-weekday (priv:make-locale-reader
1405
priv:locale-abbr-weekday->index))
1406
(locale-reader-long-weekday (priv:make-locale-reader
1407
priv:locale-long-weekday->index))
1408
(locale-reader-abbr-month (priv:make-locale-reader
1409
priv:locale-abbr-month->index))
1410
(locale-reader-long-month (priv:make-locale-reader
1411
priv:locale-long-month->index))
1412
(char-fail (lambda (ch) #t))
1413
(do-nothing (lambda (val object) (values))))
1416
(list #\~ char-fail (priv:make-char-id-reader #\~) do-nothing)
1417
(list #\a char-alphabetic? locale-reader-abbr-weekday do-nothing)
1418
(list #\A char-alphabetic? locale-reader-long-weekday do-nothing)
1419
(list #\b char-alphabetic? locale-reader-abbr-month
1420
(lambda (val object)
1421
(set-date-month! object val)))
1422
(list #\B char-alphabetic? locale-reader-long-month
1423
(lambda (val object)
1424
(set-date-month! object val)))
1425
(list #\d char-numeric? ireader2 (lambda (val object)
1428
(list #\e char-fail eireader2 (lambda (val object)
1429
(set-date-day! object val)))
1430
(list #\h char-alphabetic? locale-reader-abbr-month
1431
(lambda (val object)
1432
(set-date-month! object val)))
1433
(list #\H char-numeric? ireader2 (lambda (val object)
1434
(set-date-hour! object val)))
1435
(list #\k char-fail eireader2 (lambda (val object)
1436
(set-date-hour! object val)))
1437
(list #\m char-numeric? ireader2 (lambda (val object)
1438
(set-date-month! object val)))
1439
(list #\M char-numeric? ireader2 (lambda (val object)
1442
(list #\S char-numeric? ireader2 (lambda (val object)
1443
(set-date-second! object val)))
1444
(list #\y char-fail eireader2
1445
(lambda (val object)
1446
(set-date-year! object (priv:natural-year val))))
1447
(list #\Y char-numeric? ireader4 (lambda (val object)
1448
(set-date-year! object val)))
1449
(list #\z (lambda (c)
1454
priv:zone-reader (lambda (val object)
1455
(set-date-zone-offset! object val))))))
1457
(define (priv:string->date date index format-string str-len port template-string)
1458
(define (skip-until port skipper)
1459
(let ((ch (peek-char port)))
1460
(if (eof-object? port)
1461
(priv:time-error 'string->date 'bad-date-format-string template-string)
1462
(if (not (skipper ch))
1463
(begin (read-char port) (skip-until port skipper))))))
1464
(if (>= index str-len)
1467
(let ((current-char (string-ref format-string index)))
1468
(if (not (char=? current-char #\~))
1469
(let ((port-char (read-char port)))
1470
(if (or (eof-object? port-char)
1471
(not (char=? current-char port-char)))
1472
(priv:time-error 'string->date
1473
'bad-date-format-string template-string))
1474
(priv:string->date date
1480
;; otherwise, it's an escape, we hope
1481
(if (> (+ index 1) str-len)
1482
(priv:time-error 'string->date
1483
'bad-date-format-string template-string)
1484
(let* ((format-char (string-ref format-string (+ index 1)))
1485
(format-info (assoc format-char priv:read-directives)))
1486
(if (not format-info)
1487
(priv:time-error 'string->date
1488
'bad-date-format-string template-string)
1490
(let ((skipper (cadr format-info))
1491
(reader (caddr format-info))
1492
(actor (cadddr format-info)))
1493
(skip-until port skipper)
1494
(let ((val (reader port)))
1495
(if (eof-object? val)
1496
(priv:time-error 'string->date
1497
'bad-date-format-string
1500
(priv:string->date date
1505
template-string))))))))))
1507
(define (string->date input-string template-string)
1508
(define (priv:date-ok? date)
1509
(and (date-nanosecond date)
1516
(date-zone-offset date)))
1517
(let ((newdate (make-date 0 0 0 0 #f #f #f #f)))
1518
(priv:string->date newdate
1521
(string-length template-string)
1522
(open-input-string input-string)
1524
(if (not (date-zone-offset newdate))
1526
;; this is necessary to get DST right -- as far as we can
1527
;; get it right (think of the double/missing hour in the
1528
;; night when we are switching between normal time and DST).
1529
(set-date-zone-offset! newdate
1530
(priv:local-tz-offset
1531
(make-time time-utc 0 0)))
1532
(set-date-zone-offset! newdate
1533
(priv:local-tz-offset
1534
(date->time-utc newdate)))))
1535
(if (priv:date-ok? newdate)
1539
'bad-date-format-string
1540
(list "Incomplete date read. " newdate template-string)))))
1542
;;; srfi-19.scm ends here
added
removed
srfi/srfi-19.scm
