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;;; srfi-19.scm --- Time/Date Library | |
;; Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009 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 2.1 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 | |
;; (PRIV: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-6) | |
:use-module (srfi srfi-8) | |
:use-module (srfi srfi-9) | |
:autoload (ice-9 rdelim) (read-line)) | |
(begin-deprecated | |
;; Prevent `export' from re-exporting core bindings. This behaviour | |
;; of `export' is deprecated and will disappear in one of the next | |
;; releases. | |
(define current-time #f)) | |
(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 | |
current-time | |
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->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 | |
(define priv:locale-number-separator ".") | |
(define priv:locale-abbr-weekday-vector | |
(vector "Sun" "Mon" "Tue" "Wed" "Thu" "Fri" "Sat")) | |
(define priv:locale-long-weekday-vector | |
(vector | |
"Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday")) | |
;; note empty string in 0th place. | |
(define priv:locale-abbr-month-vector | |
(vector "" | |
"Jan" | |
"Feb" | |
"Mar" | |
"Apr" | |
"May" | |
"Jun" | |
"Jul" | |
"Aug" | |
"Sep" | |
"Oct" | |
"Nov" | |
"Dec")) | |
(define priv:locale-long-month-vector | |
(vector "" | |
"January" | |
"February" | |
"March" | |
"April" | |
"May" | |
"June" | |
"July" | |
"August" | |
"September" | |
"October" | |
"November" | |
"December")) | |
(define priv:locale-pm "PM") | |
(define priv:locale-am "AM") | |
;; See date->string | |
(define priv:locale-date-time-format "~a ~b ~d ~H:~M:~S~z ~Y") | |
(define priv:locale-short-date-format "~m/~d/~y") | |
(define priv:locale-time-format "~H:~M:~S") | |
(define priv:iso-8601-date-time-format "~Y-~m-~dT~H:~M:~S~z") | |
;;-- Miscellaneous Constants. | |
;;-- only the priv:tai-epoch-in-jd might need changing if | |
;; a different epoch is used. | |
(define priv:nano 1000000000) ; nanoseconds in a second | |
(define priv:sid 86400) ; seconds in a day | |
(define priv:sihd 43200) ; seconds in a half day | |
(define priv:tai-epoch-in-jd 4881175/2) ; julian day number for 'the epoch' | |
;; FIXME: should this be something other than misc-error? | |
(define (priv: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 abover | |
;; format and creates the leap second table | |
;; it also calls the almost standard, but not R5 procedures read-line | |
;; & open-input-string | |
;; ie (set! priv:leap-second-table (priv:read-tai-utc-date "tai-utc.dat")) | |
(define (priv:read-tai-utc-data filename) | |
(define (convert-jd jd) | |
(* (- (inexact->exact jd) priv:tai-epoch-in-jd) priv: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 priv:leap-second-table | |
'((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! priv:leap-second-table (priv:read-tai-utc-data filename)) | |
(values)) | |
(define (priv:leap-second-delta utc-seconds) | |
(letrec ((lsd (lambda (table) | |
(cond ((>= utc-seconds (caar table)) | |
(cdar table)) | |
(else (lsd (cdr table))))))) | |
(if (< utc-seconds (* (- 1972 1970) 365 priv:sid)) 0 | |
(lsd priv:leap-second-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 (priv:split-real r) | |
(if (integer? r) | |
(values (inexact->exact r) 0) | |
(let ((l (truncate r))) | |
(values (inexact->exact l) (- r l))))) | |
(define (priv:time-normalize! t) | |
(if (>= (abs (time-nanosecond t)) 1000000000) | |
(receive (int frac) | |
(priv:split-real (time-nanosecond t)) | |
(set-time-second! t (+ (time-second t) | |
(quotient int 1000000000))) | |
(set-time-nanosecond! t (+ (remainder int 1000000000) | |
frac)))) | |
(if (and (positive? (time-second t)) | |
(negative? (time-nanosecond t))) | |
(begin | |
(set-time-second! t (- (time-second t) 1)) | |
(set-time-nanosecond! t (+ 1000000000 (time-nanosecond t)))) | |
(if (and (negative? (time-second t)) | |
(positive? (time-nanosecond t))) | |
(begin | |
(set-time-second! t (+ (time-second t) 1)) | |
(set-time-nanosecond! t (+ 1000000000 (time-nanosecond t)))))) | |
t) | |
(define (make-time type nanosecond second) | |
(priv:time-normalize! (make-time-unnormalized type nanosecond second))) | |
;; Helpers | |
;; FIXME: finish this and publish it? | |
(define (date->broken-down-time date) | |
(let ((result (mktime 0))) | |
;; FIXME: What should we do about leap-seconds which may overflow | |
;; set-tm:sec? | |
(set-tm:sec result (date-second date)) | |
(set-tm:min result (date-minute date)) | |
(set-tm:hour result (date-hour date)) | |
;; FIXME: SRFI day ranges from 0-31. (not compatible with set-tm:mday). | |
(set-tm:mday result (date-day date)) | |
(set-tm:mon result (- (date-month date) 1)) | |
;; FIXME: need to signal error on range violation. | |
(set-tm:year result (+ 1900 (date-year date))) | |
(set-tm:isdst result -1) | |
(set-tm:gmtoff result (- (date-zone-offset date))) | |
result)) | |
;;; current-time | |
;;; specific time getters. | |
(define (priv:current-time-utc) | |
;; Resolution is microseconds. | |
(let ((tod (gettimeofday))) | |
(make-time time-utc (* (cdr tod) 1000) (car tod)))) | |
(define (priv:current-time-tai) | |
;; Resolution is microseconds. | |
(let* ((tod (gettimeofday)) | |
(sec (car tod)) | |
(usec (cdr tod))) | |
(make-time time-tai | |
(* usec 1000) | |
(+ (car tod) (priv:leap-second-delta sec))))) | |
;;(define (priv: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 implemation of current-time-montonic | |
;; will require rewriting all of the time-monotonic converters, | |
;; of course. | |
(define (priv:current-time-monotonic) | |
;; Resolution is microseconds. | |
(priv:current-time-tai)) | |
(define (priv:current-time-thread) | |
(priv:time-error 'current-time 'unsupported-clock-type 'time-thread)) | |
(define priv:ns-per-guile-tick (/ 1000000000 internal-time-units-per-second)) | |
(define (priv:current-time-process) | |
(let ((run-time (get-internal-run-time))) | |
(make-time | |
time-process | |
(* (remainder run-time internal-time-units-per-second) | |
priv:ns-per-guile-tick) | |
(quotient run-time internal-time-units-per-second)))) | |
;;(define (priv:current-time-gc) | |
;; (priv: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) (priv:current-time-tai)) | |
((eq? clock-type time-utc) (priv:current-time-utc)) | |
((eq? clock-type time-monotonic) (priv:current-time-monotonic)) | |
((eq? clock-type time-thread) (priv:current-time-thread)) | |
((eq? clock-type time-process) (priv:current-time-process)) | |
;; ((eq? clock-type time-gc) (priv:current-time-gc)) | |
(else (priv: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) priv:ns-per-guile-tick) | |
;; ((eq? clock-type time-thread) 1000) | |
;; ((eq? clock-type time-gc) 10000) | |
(else (priv:time-error 'time-resolution 'invalid-clock-type clock-type))))) | |
;; -- Time comparisons | |
(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. | |
(and (= (time-second t1) (time-second t2)) | |
(= (time-nanosecond t1) (time-nanosecond t2)) | |
(eq? (time-type t1) (time-type t2)))) | |
(define (time>? t1 t2) | |
(or (> (time-second t1) (time-second t2)) | |
(and (= (time-second t1) (time-second t2)) | |
(> (time-nanosecond t1) (time-nanosecond t2))))) | |
(define (time<? t1 t2) | |
(or (< (time-second t1) (time-second t2)) | |
(and (= (time-second t1) (time-second t2)) | |
(< (time-nanosecond t1) (time-nanosecond t2))))) | |
(define (time>=? t1 t2) | |
(or (> (time-second t1) (time-second t2)) | |
(and (= (time-second t1) (time-second t2)) | |
(>= (time-nanosecond t1) (time-nanosecond t2))))) | |
(define (time<=? t1 t2) | |
(or (< (time-second t1) (time-second t2)) | |
(and (= (time-second t1) (time-second t2)) | |
(<= (time-nanosecond t1) (time-nanosecond t2))))) | |
;; -- Time arithmetic | |
(define (time-difference! time1 time2) | |
(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) | |
(priv: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)) | |
(priv: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) | |
(priv: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)) | |
(priv:time-error 'add-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) | |
(priv: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)) | |
(priv: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 (- (time-second time-in) | |
(priv:leap-second-delta | |
(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)) | |
(priv: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 (+ (time-second time-in) | |
(priv:leap-second-delta | |
(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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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)) | |
(priv: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 (priv: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) | |
(quotient y 4) | |
(- (quotient y 100)) | |
(quotient y 400) | |
-32045))) | |
;; gives the seconds/date/month/year | |
(define (priv:decode-julian-day-number jdn) | |
(let* ((days (inexact->exact (truncate jdn))) | |
(a (+ days 32044)) | |
(b (quotient (+ (* 4 a) 3) 146097)) | |
(c (- a (quotient (* 146097 b) 4))) | |
(d (quotient (+ (* 4 c) 3) 1461)) | |
(e (- c (quotient (* 1461 d) 4))) | |
(m (quotient (+ (* 5 e) 2) 153)) | |
(y (+ (* 100 b) d -4800 (quotient m 10)))) | |
(values ; seconds date month year | |
(* (- jdn days) priv: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 (priv:local-tz-offset utc-time) | |
;; SRFI uses seconds West, but guile (and libc) use seconds East. | |
(- (tm:gmtoff (localtime (time-second utc-time))))) | |
;; special thing -- ignores nanos | |
(define (priv:time->julian-day-number seconds tz-offset) | |
(+ (/ (+ seconds tz-offset priv:sihd) | |
priv:sid) | |
priv:tai-epoch-in-jd)) | |
(define (priv:leap-second? second) | |
(and (assoc second priv:leap-second-table) #t)) | |
(define (time-utc->date time . tz-offset) | |
(if (not (eq? (time-type time) time-utc)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(let* ((offset (if (null? tz-offset) | |
(priv:local-tz-offset time) | |
(car tz-offset))) | |
(leap-second? (priv:leap-second? (+ offset (time-second time)))) | |
(jdn (priv:time->julian-day-number (if leap-second? | |
(- (time-second time) 1) | |
(time-second time)) | |
offset))) | |
(call-with-values (lambda () (priv: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 (time-nanosecond time) | |
(if leap-second? (+ seconds 1) seconds) | |
minutes | |
hours | |
date | |
month | |
year | |
offset)))))) | |
(define (time-tai->date time . tz-offset) | |
(if (not (eq? (time-type time) time-tai)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(let* ((offset (if (null? tz-offset) | |
(priv:local-tz-offset (time-tai->time-utc time)) | |
(car tz-offset))) | |
(seconds (- (time-second time) | |
(priv:leap-second-delta (time-second time)))) | |
(leap-second? (priv:leap-second? (+ offset seconds))) | |
(jdn (priv:time->julian-day-number (if leap-second? | |
(- seconds 1) | |
seconds) | |
offset))) | |
(call-with-values (lambda () (priv: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. | |
;; adjust for leap seconds if necessary ... | |
(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 (time-nanosecond time) | |
(if leap-second? (+ seconds 1) seconds) | |
minutes | |
hours | |
date | |
month | |
year | |
offset)))))) | |
;; this is the same as time-tai->date. | |
(define (time-monotonic->date time . tz-offset) | |
(if (not (eq? (time-type time) time-monotonic)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(let* ((offset (if (null? tz-offset) | |
(priv:local-tz-offset (time-monotonic->time-utc time)) | |
(car tz-offset))) | |
(seconds (- (time-second time) | |
(priv:leap-second-delta (time-second time)))) | |
(leap-second? (priv:leap-second? (+ offset seconds))) | |
(jdn (priv:time->julian-day-number (if leap-second? | |
(- seconds 1) | |
seconds) | |
offset))) | |
(call-with-values (lambda () (priv: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. | |
;; adjust for leap seconds if necessary ... | |
(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 (time-nanosecond time) | |
(if leap-second? (+ seconds 1) seconds) | |
minutes | |
hours | |
date | |
month | |
year | |
offset)))))) | |
(define (date->time-utc date) | |
(let* ((jdays (- (priv:encode-julian-day-number (date-day date) | |
(date-month date) | |
(date-year date)) | |
priv:tai-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 date) | |
(time-utc->time-tai! (date->time-utc date))) | |
(define (date->time-monotonic date) | |
(time-utc->time-monotonic! (date->time-utc date))) | |
(define (priv:leap-year? year) | |
(or (= (modulo year 400) 0) | |
(and (= (modulo year 4) 0) (not (= (modulo year 100) 0))))) | |
(define (leap-year? date) | |
(priv:leap-year? (date-year date))) | |
;; 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 priv: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 (priv:year-day day month year) | |
(let ((days-pr (assoc month priv:month-assoc))) | |
(if (not days-pr) | |
(priv:time-error 'date-year-day 'invalid-month-specification month)) | |
(if (and (priv:leap-year? year) (> month 2)) | |
(+ day (cdr days-pr) 1) | |
(+ day (cdr days-pr))))) | |
(define (date-year-day date) | |
(priv:year-day (date-day date) (date-month date) (date-year date))) | |
;; from calendar faq | |
(define (priv:week-day day month year) | |
(let* ((a (quotient (- 14 month) 12)) | |
(y (- year a)) | |
(m (+ month (* 12 a) -2))) | |
(modulo (+ day | |
y | |
(quotient y 4) | |
(- (quotient y 100)) | |
(quotient y 400) | |
(quotient (* 31 m) 12)) | |
7))) | |
(define (date-week-day date) | |
(priv:week-day (date-day date) (date-month date) (date-year date))) | |
(define (priv: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) | |
(quotient (- (date-year-day date) | |
1 | |
(priv: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) | |
(priv:local-tz-offset time) | |
(car tz-offset))))) | |
;; given a 'two digit' number, find the year within 50 years +/- | |
(define (priv: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))) | |
(+ (priv:encode-julian-day-number day month year) | |
(- 1/2) | |
(+ (/ (+ (- offset) | |
(* hour 60 60) | |
(* minute 60) | |
second | |
(/ nanosecond priv:nano)) | |
priv: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)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(+ (/ (+ (time-second time) (/ (time-nanosecond time) priv:nano)) | |
priv:sid) | |
priv:tai-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)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(+ (/ (+ (- (time-second time) | |
(priv:leap-second-delta (time-second time))) | |
(/ (time-nanosecond time) priv:nano)) | |
priv:sid) | |
priv:tai-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)) | |
(priv:time-error 'time->date 'incompatible-time-types time)) | |
(+ (/ (+ (- (time-second time) | |
(priv:leap-second-delta (time-second time))) | |
(/ (time-nanosecond time) priv:nano)) | |
priv:sid) | |
priv:tai-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 (* priv:sid (- jdn priv:tai-epoch-in-jd)))) | |
(receive (seconds parts) | |
(priv:split-real secs) | |
(make-time time-utc | |
(* parts priv: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) | |
(priv: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 (priv: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 (priv:last-n-digits i n) | |
(abs (remainder i (expt 10 n)))) | |
(define (priv:locale-abbr-weekday n) | |
(vector-ref priv:locale-abbr-weekday-vector n)) | |
(define (priv:locale-long-weekday n) | |
(vector-ref priv:locale-long-weekday-vector n)) | |
(define (priv:locale-abbr-month n) | |
(vector-ref priv:locale-abbr-month-vector n)) | |
(define (priv:locale-long-month n) | |
(vector-ref priv:locale-long-month-vector n)) | |
(define (priv:vector-find needle haystack comparator) | |
(let ((len (vector-length haystack))) | |
(define (priv:vector-find-int index) | |
(cond | |
((>= index len) #f) | |
((comparator needle (vector-ref haystack index)) index) | |
(else (priv:vector-find-int (+ index 1))))) | |
(priv:vector-find-int 0))) | |
(define (priv:locale-abbr-weekday->index string) | |
(priv:vector-find string priv:locale-abbr-weekday-vector string=?)) | |
(define (priv:locale-long-weekday->index string) | |
(priv:vector-find string priv:locale-long-weekday-vector string=?)) | |
(define (priv:locale-abbr-month->index string) | |
(priv:vector-find string priv:locale-abbr-month-vector string=?)) | |
(define (priv:locale-long-month->index string) | |
(priv:vector-find string priv:locale-long-month-vector string=?)) | |
;; FIXME: mkoeppe: Put a symbolic time zone in the date structs. | |
;; Print it here instead of the numerical offset if available. | |
(define (priv:locale-print-time-zone date port) | |
(priv:tz-printer (date-zone-offset date) port)) | |
;; FIXME: we should use strftime to determine this dynamically if possible. | |
;; Again, locale specific. | |
(define (priv:locale-am/pm hr) | |
(if (> hr 11) priv:locale-pm priv:locale-am)) | |
(define (priv: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 (priv:padding hours #\0 2) port) | |
(display (priv: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 priv:directives | |
(list | |
(cons #\~ (lambda (date pad-with port) | |
(display #\~ port))) | |
(cons #\a (lambda (date pad-with port) | |
(display (priv:locale-abbr-weekday (date-week-day date)) | |
port))) | |
(cons #\A (lambda (date pad-with port) | |
(display (priv:locale-long-weekday (date-week-day date)) | |
port))) | |
(cons #\b (lambda (date pad-with port) | |
(display (priv:locale-abbr-month (date-month date)) | |
port))) | |
(cons #\B (lambda (date pad-with port) | |
(display (priv:locale-long-month (date-month date)) | |
port))) | |
(cons #\c (lambda (date pad-with port) | |
(display (date->string date priv:locale-date-time-format) port))) | |
(cons #\d (lambda (date pad-with port) | |
(display (priv: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 (priv:padding (date-day date) | |
#\Space 2) | |
port))) | |
(cons #\f (lambda (date pad-with port) | |
(if (> (date-nanosecond date) | |
priv:nano) | |
(display (priv:padding (+ (date-second date) 1) | |
pad-with 2) | |
port) | |
(display (priv:padding (date-second date) | |
pad-with 2) | |
port)) | |
(receive (i f) | |
(priv:split-real (/ | |
(date-nanosecond date) | |
priv:nano 1.0)) | |
(let* ((ns (number->string f)) | |
(le (string-length ns))) | |
(if (> le 2) | |
(begin | |
(display priv:locale-number-separator port) | |
(display (substring ns 2 le) port))))))) | |
(cons #\h (lambda (date pad-with port) | |
(display (date->string date "~b") port))) | |
(cons #\H (lambda (date pad-with port) | |
(display (priv:padding (date-hour date) | |
pad-with 2) | |
port))) | |
(cons #\I (lambda (date pad-with port) | |
(let ((hr (date-hour date))) | |
(if (> hr 12) | |
(display (priv:padding (- hr 12) | |
pad-with 2) | |
port) | |
(display (priv:padding hr | |
pad-with 2) | |
port))))) | |
(cons #\j (lambda (date pad-with port) | |
(display (priv:padding (date-year-day date) | |
pad-with 3) | |
port))) | |
(cons #\k (lambda (date pad-with port) | |
(display (priv: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 (priv:padding hr #\Space 2) | |
port)))) | |
(cons #\m (lambda (date pad-with port) | |
(display (priv:padding (date-month date) | |
pad-with 2) | |
port))) | |
(cons #\M (lambda (date pad-with port) | |
(display (priv: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 (priv:padding (date-nanosecond date) | |
pad-with 7) | |
port))) | |
(cons #\p (lambda (date pad-with port) | |
(display (priv:locale-am/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) | |
priv:nano) | |
(display (priv:padding (+ (date-second date) 1) | |
pad-with 2) | |
port) | |
(display (priv: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 (> (priv:days-before-first-week date 0) 0) | |
(display (priv:padding (+ (date-week-number date 0) 1) | |
#\0 2) port) | |
(display (priv:padding (date-week-number date 0) | |
#\0 2) port)))) | |
(cons #\V (lambda (date pad-with port) | |
(display (priv: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 priv:locale-short-date-format) port))) | |
(cons #\X (lambda (date pad-with port) | |
(display (date->string date priv:locale-time-format) port))) | |
(cons #\W (lambda (date pad-with port) | |
(if (> (priv:days-before-first-week date 1) 0) | |
(display (priv:padding (+ (date-week-number date 1) 1) | |
#\0 2) port) | |
(display (priv:padding (date-week-number date 1) | |
#\0 2) port)))) | |
(cons #\y (lambda (date pad-with port) | |
(display (priv:padding (priv:last-n-digits | |
(date-year date) 2) | |
pad-with | |
2) | |
port))) | |
(cons #\Y (lambda (date pad-with port) | |
(display (date-year date) port))) | |
(cons #\z (lambda (date pad-with port) | |
(priv:tz-printer (date-zone-offset date) port))) | |
(cons #\Z (lambda (date pad-with port) | |
(priv: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 "~k:~M:~S~z") port))) | |
(cons #\3 (lambda (date pad-with port) | |
(display (date->string date "~k:~M:~S") port))) | |
(cons #\4 (lambda (date pad-with port) | |
(display (date->string date "~Y-~m-~dT~k:~M:~S~z") port))) | |
(cons #\5 (lambda (date pad-with port) | |
(display (date->string date "~Y-~m-~dT~k:~M:~S") port))))) | |
(define (priv:get-formatter char) | |
(let ((associated (assoc char priv:directives))) | |
(if associated (cdr associated) #f))) | |
(define (priv:date-printer date index format-string str-len port) | |
(if (>= index str-len) | |
(values) | |
(let ((current-char (string-ref format-string index))) | |
(if (not (char=? current-char #\~)) | |
(begin | |
(display current-char port) | |
(priv:date-printer date (+ index 1) format-string str-len port)) | |
(if (= (+ index 1) str-len) ; bad format string. | |
(priv:time-error 'priv: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. | |
(priv:time-error 'priv:date-printer | |
'bad-date-format-string | |
format-string) | |
(let ((formatter (priv:get-formatter | |
(string-ref format-string | |
(+ index 2))))) | |
(if (not formatter) | |
(priv:time-error 'priv:date-printer | |
'bad-date-format-string | |
format-string) | |
(begin | |
(formatter date #f port) | |
(priv:date-printer date | |
(+ index 3) | |
format-string | |
str-len | |
port)))))) | |
((char=? pad-char? #\_) | |
(if (= (+ index 2) str-len) ; bad format string. | |
(priv:time-error 'priv:date-printer | |
'bad-date-format-string | |
format-string) | |
(let ((formatter (priv:get-formatter | |
(string-ref format-string | |
(+ index 2))))) | |
(if (not formatter) | |
(priv:time-error 'priv:date-printer | |
'bad-date-format-string | |
format-string) | |
(begin | |
(formatter date #\Space port) | |
(priv:date-printer date | |
(+ index 3) | |
format-string | |
str-len | |
port)))))) | |
(else | |
(let ((formatter (priv:get-formatter | |
(string-ref format-string | |
(+ index 1))))) | |
(if (not formatter) | |
(priv:time-error 'priv:date-printer | |
'bad-date-format-string | |
format-string) | |
(begin | |
(formatter date #\0 port) | |
(priv: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)))) | |
(priv:date-printer date 0 fmt-str (string-length fmt-str) str-port) | |
(get-output-string str-port))) | |
(define (priv: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 (priv:time-error 'bad-date-template-string | |
(list "Non-integer character" ch))))) | |
;; read an integer upto n characters long on port; upto -> #f is any length | |
(define (priv: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) (priv:char->int (read-char port))) | |
(+ nchars 1)))))) | |
(define (priv:make-integer-reader upto) | |
(lambda (port) | |
(priv:integer-reader upto port))) | |
;; read *exactly* n characters and convert to integer; could be padded | |
(define (priv: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) | |
(priv: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) (priv: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 | |
(priv:time-error 'string->date 'bad-date-template-string | |
"Non-numeric characters in integer read."))))) | |
(accum-int port 0 0))) | |
(define (priv:make-integer-exact-reader n) | |
(lambda (port) | |
(priv:integer-reader-exact n port))) | |
(define (priv:zone-reader port) | |
(let ((offset 0) | |
(positive? #f)) | |
(let ((ch (read-char port))) | |
(if (eof-object? ch) | |
(priv: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 | |
(priv:time-error 'string->date 'bad-date-template-string | |
(list "Invalid time zone +/-" ch)))) | |
(let ((ch (read-char port))) | |
(if (eof-object? ch) | |
(priv:time-error 'string->date 'bad-date-template-string | |
(list "Invalid time zone number" ch))) | |
(set! offset (* (priv:char->int ch) | |
10 60 60))) | |
(let ((ch (read-char port))) | |
(if (eof-object? ch) | |
(priv:time-error 'string->date 'bad-date-template-string | |
(list "Invalid time zone number" ch))) | |
(set! offset (+ offset (* (priv:char->int ch) | |
60 60)))) | |
(let ((ch (read-char port))) | |
(if (eof-object? ch) | |
(priv:time-error 'string->date 'bad-date-template-string | |
(list "Invalid time zone number" ch))) | |
(set! offset (+ offset (* (priv:char->int ch) | |
10 60)))) | |
(let ((ch (read-char port))) | |
(if (eof-object? ch) | |
(priv:time-error 'string->date 'bad-date-template-string | |
(list "Invalid time zone number" ch))) | |
(set! offset (+ offset (* (priv:char->int ch) | |
60)))) | |
(if positive? offset (- offset))))))) | |
;; looking at a char, read the char string, run thru indexer, return index | |
(define (priv: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 (priv:time-error 'string->date | |
'bad-date-template-string | |
(list "Invalid string for " indexer))))) | |
(define (priv:make-locale-reader indexer) | |
(lambda (port) | |
(priv:locale-reader port indexer))) | |
(define (priv:make-char-id-reader char) | |
(lambda (port) | |
(if (char=? char (read-char port)) | |
char | |
(priv: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. a action procedure, that takes the value (from 3.) and some | |
;; object (here, always the date) and (probably) side-effects it. | |
;; In some cases (e.g., ~A) the action is to do nothing | |
(define priv:read-directives | |
(let ((ireader4 (priv:make-integer-reader 4)) | |
(ireader2 (priv:make-integer-reader 2)) | |
(ireaderf (priv:make-integer-reader #f)) | |
(eireader2 (priv:make-integer-exact-reader 2)) | |
(eireader4 (priv:make-integer-exact-reader 4)) | |
(locale-reader-abbr-weekday (priv:make-locale-reader | |
priv:locale-abbr-weekday->index)) | |
(locale-reader-long-weekday (priv:make-locale-reader | |
priv:locale-long-weekday->index)) | |
(locale-reader-abbr-month (priv:make-locale-reader | |
priv:locale-abbr-month->index)) | |
(locale-reader-long-month (priv:make-locale-reader | |
priv:locale-long-month->index)) | |
(char-fail (lambda (ch) #t)) | |
(do-nothing (lambda (val object) (values)))) | |
(list | |
(list #\~ char-fail (priv:make-char-id-reader #\~) do-nothing) | |
(list #\a char-alphabetic? locale-reader-abbr-weekday do-nothing) | |
(list #\A char-alphabetic? locale-reader-long-weekday do-nothing) | |
(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 #\S char-numeric? ireader2 (lambda (val object) | |
(set-date-second! object val))) | |
(list #\y char-fail eireader2 | |
(lambda (val object) | |
(set-date-year! object (priv:natural-year val)))) | |
(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 #\-))) | |
priv: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) | |
(priv: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) | |
(begin | |
(values)) | |
(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))) | |
(priv: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) | |
(priv:time-error 'string->date | |
'bad-date-format-string template-string) | |
(let* ((format-char (string-ref format-string (+ index 1))) | |
(format-info (assoc format-char priv:read-directives))) | |
(if (not format-info) | |
(priv: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) | |
(priv:time-error 'string->date | |
'bad-date-format-string | |
template-string) | |
(actor val date))) | |
(priv:string->date date | |
(+ index 2) | |
format-string | |
str-len | |
port | |
template-string)))))))))) | |
(define (string->date input-string template-string) | |
(define (priv: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 | |
(priv:local-tz-offset | |
(make-time time-utc 0 0))) | |
(set-date-zone-offset! newdate | |
(priv:local-tz-offset | |
(date->time-utc newdate))))) | |
(if (priv:date-ok? newdate) | |
newdate | |
(priv:time-error | |
'string->date | |
'bad-date-format-string | |
(list "Incomplete date read. " newdate template-string))))) | |
;;; srfi-19.scm ends here | |