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authorTomas Volf <~@wolfsden.cz>2025-01-24 17:23:17 +0100
committerDaniel Llorens <lloda@sarc.name>2025-02-28 10:28:06 +0100
commitc1353972ee780f1996867fe97d0c143c59bb61ab (patch)
tree05e4110e4eef349044dac2eeb9f3c3c214179e91
parent46a0ee777959fa215a5a8cba6cf42888731642a7 (diff)
downloadguile-c1353972ee780f1996867fe97d0c143c59bb61ab.tar.gz
srfi-19: Fix ~V converter in date->string.
The ~V is supposed to print ISO week number, not a week number. This commit fixes that. * module/srfi/srfi-19.scm (date-week-number-iso): New procedure taken from the reference implementation. (directives)<#\V>: Use it. * test-suite/tests/srfi-19.test ("date->string ~V"): Add tests taken from the reference test suite. * doc/ref/srfi-modules.texi (SRFI-19 Date to string): Mention ISO-8601 in description for ~V. Fixes <https://bugs.gnu.org/74841>. Edited by lloda <lloda@sarc.name>.
-rw-r--r--doc/ref/srfi-modules.texi4
-rw-r--r--module/srfi/srfi-19.scm23
-rw-r--r--test-suite/tests/srfi-19.test59
3 files changed, 81 insertions, 5 deletions
diff --git a/doc/ref/srfi-modules.texi b/doc/ref/srfi-modules.texi
index f072e6c3f..0b663902e 100644
--- a/doc/ref/srfi-modules.texi
+++ b/doc/ref/srfi-modules.texi
@@ -2864,8 +2864,8 @@ with locale decimal point, eg.@: @samp{5.2}
@item @nicode{~T} @tab time, 24 hour clock, @samp{~H:~M:~S}
@item @nicode{~U} @tab week of year, Sunday first day of week,
@samp{00} to @samp{52}
-@item @nicode{~V} @tab week of year, Monday first day of week,
-@samp{01} to @samp{53}
+@item @nicode{~V} @tab ISO 8601 week number of the year,
+Monday first day of week, @samp{01} to @samp{53}
@item @nicode{~w} @tab day of week, 0 for Sunday, @samp{0} to @samp{6}
@item @nicode{~W} @tab week of year, Monday first day of week,
@samp{00} to @samp{52}
diff --git a/module/srfi/srfi-19.scm b/module/srfi/srfi-19.scm
index d809ac1ec..6ade40645 100644
--- a/module/srfi/srfi-19.scm
+++ b/module/srfi/srfi-19.scm
@@ -753,6 +753,27 @@
(days-before-first-week date day-of-week-starting-week))
7))
+;;; Adapted from the reference implementation.
+(define (date-week-number-iso date)
+ "Return a ISO-8601 week number for the @var{date}."
+ ;; The week with the year's first Thursday is week 01.
+ (let* ((first-day-of-the-week (week-day 1 1 (date-year date)))
+ (offset (if (> first-day-of-the-week 4) 0 1))
+ ;; -2: decrement one day to compensate 1-origin of date-year-day,
+ ;; and decrement one more day for Sunday belongs to the previous week.
+ (w (+ (floor-quotient (+ (date-year-day date) first-day-of-the-week -2)
+ 7)
+ offset)))
+ (cond ((zero? w)
+ ;; date belongs to the last week of the previous year
+ (date-week-number-iso (make-date 0 0 0 0 31 12
+ (- (date-year date) 1) 0)))
+ ((and (= w 53)
+ (<= (week-day 1 1 (+ (date-year date) 1)) 4))
+ ;; date belongs to the first week of the next year
+ 1)
+ (else w))))
+
(define (current-date . tz-offset)
(let ((time (current-time time-utc)))
(time-utc->date
@@ -1043,7 +1064,7 @@
(display (padding (date-week-number date 0)
#\0 2) port))))
(cons #\V (lambda (date pad-with port)
- (display (padding (date-week-number date 1)
+ (display (padding (date-week-number-iso date)
#\0 2) port)))
(cons #\w (lambda (date pad-with port)
(display (date-week-day date) port)))
diff --git a/test-suite/tests/srfi-19.test b/test-suite/tests/srfi-19.test
index 55eb82320..8d3198b16 100644
--- a/test-suite/tests/srfi-19.test
+++ b/test-suite/tests/srfi-19.test
@@ -26,7 +26,8 @@
#:use-module (test-suite lib)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-19)
- #:use-module (ice-9 format))
+ #:use-module (ice-9 format)
+ #:use-module (ice-9 match))
;; Make sure we use the default locale.
(when (defined? 'setlocale)
@@ -412,7 +413,61 @@ incomplete numerical tower implementation.)"
(with-test-prefix "date-week-number"
(pass-if (= 0 (date-week-number (make-date 0 0 0 0 1 1 1984 0) 0)))
(pass-if (= 0 (date-week-number (make-date 0 0 0 0 7 1 1984 0) 0)))
- (pass-if (= 1 (date-week-number (make-date 0 0 0 0 8 1 1984 0) 0)))))
+ (pass-if (= 1 (date-week-number (make-date 0 0 0 0 8 1 1984 0) 0))))
+
+ (let ((convert (match-lambda
+ ((y m d)
+ (date->string (make-date 0 0 0 0 d m y 0)
+ "~V")))))
+ ;; Taken from the test suite for the reference implementation.
+ (with-test-prefix "date->string ~V"
+ (pass-if-equal "Thursday, week 53" "53"
+ (convert '(2020 12 31)))
+ (pass-if-equal "Friday, week 53 (previous year)" "53"
+ (convert '(2021 1 1)))
+ (pass-if-equal "Sunday, week 53 (previous year)" "53"
+ (convert '(2021 1 3)))
+ (pass-if-equal "Monday, week 1" "01"
+ (convert '(2021 1 4)))
+
+ (pass-if-equal "Sunday, week 52" "52"
+ (convert '(2019 12 29)))
+ (pass-if-equal "Monday, week 1 (next year)" "01"
+ (convert '(2019 12 30)))
+ (pass-if-equal "Tuesday, week 1 (next year)" "01"
+ (convert '(2019 12 31)))
+ (pass-if-equal "Wednesday, week 1" "01"
+ (convert '(2020 1 1)))
+
+ (pass-if-equal "Saturday, week 52" "52"
+ (convert '(2016 12 31)))
+ (pass-if-equal "Sunday, week 52 (previous year)" "52"
+ (convert '(2017 1 1)))
+ (pass-if-equal "Monday, week 1" "01"
+ (convert '(2017 1 2)))
+ (pass-if-equal "Sunday, week 1" "01"
+ (convert '(2017 1 8)))
+ (pass-if-equal "Monday, week 2" "02"
+ (convert '(2017 1 9)))
+
+ (pass-if-equal "Sunday, week 52" "52"
+ (convert '(2014 12 28)))
+ (pass-if-equal "Monday, week 1 (next year)" "01"
+ (convert '(2014 12 29)))
+ (pass-if-equal "Tuesday, week 1 (next year)" "01"
+ (convert '(2014 12 30)))
+ (pass-if-equal "Wednesday, week 1 (next year)" "01"
+ (convert '(2014 12 31)))
+ (pass-if-equal "Thursday, week 1" "01"
+ (convert '(2015 1 1)))
+ (pass-if-equal "Friday, week 1" "01"
+ (convert '(2015 1 2)))
+ (pass-if-equal "Saturday, week 1" "01"
+ (convert '(2015 1 3)))
+ (pass-if-equal "Sunday, week 1" "01"
+ (convert '(2015 1 4)))
+ (pass-if-equal "Monday, week 2" "02"
+ (convert '(2015 1 5))))))
;; Local Variables: