Move some functions to time-date

3 files changed, 86 insertions, 42 deletions

diff --git a/lisp/calendar/iso8601.el b/lisp/calendar/iso8601.el
index 3c2e31038eb..45004c46b4e 100644
--- a/lisp/calendar/iso8601.el
+++ b/lisp/calendar/iso8601.el
@@ -87,12 +87,12 @@
        ;; Monday 29 December 2008 is written "2009-W01-1".
        ((< ordinal 1)
         (setq year (1- year)
-              ordinal (+ ordinal (iso8601-days-in-year year))))
+              ordinal (+ ordinal (time-days-in-year year))))
        ;; Sunday 3 January 2010 is written "2009-W53-7".
        ((> ordinal (iso8601-days-in-year year))
-        (setq ordinal (- ordinal (iso8601-days-in-year year))
+        (setq ordinal (- ordinal (time-days-in-year year))
               year (1+ year))))
-      (let ((month-day (iso8601-ordinal-to-date year ordinal)))
+      (let ((month-day (time-ordinal-to-date year ordinal)))
         (make-decoded-time :year year
                            :month (car month-day)
                            :day (cdr month-day)))))
@@ -158,30 +158,6 @@ Return the number of minutes."
               (* (iso8601-parse-zone zone-string) 60)))
       date)))
 
-(defun iso8601-days-in-year (year)
-  (if (and (zerop (% year 4))
-           (if (zerop (% year 100))
-               (not (zerop (% year 400)))
-             t))
-      366
-    365))
-
-(defun iso8601-days-in-month (year month)
-  (if (= month 2)
-      (if (= (iso8601-days-in-year year) 365)
-          28
-        29)
-    (if (memq month '(1 3 5 7 8 10 12))
-        31
-     30)))
-
-(defun iso8601-ordinal-to-date (year ordinal)
-  (let ((month 1))
-    (while (> ordinal (iso8601-days-in-month year month))
-      (setq ordinal (- ordinal (iso8601-days-in-month year month))
-            month (1+ month)))
-    (cons month ordinal)))
-
 (defun iso8601-parse-duration (string)
   "Parse ISO 8601 durations on the form P3Y6M4DT12H30M5S."
   (cond
@@ -253,38 +229,38 @@ Return the number of minutes."
 ;; (format-time-string "%FT%T" (iso8601-parse-date "--0201"))
 ;; "0000-02-01T00:00:00"
 
-;; (iso8601-days-in-year 1999)
+;; (time-days-in-year 1999)
 ;; 365
 
-;; (iso8601-days-in-year 1900)
+;; (time-days-in-year 1900)
 ;; 366
 
-;; (iso8601-days-in-year 1996)
+;; (time-days-in-year 1996)
 ;; 366
 
-;; (iso8601-days-in-year 2000)
+;; (time-days-in-year 2000)
 ;; 365
 
-;; (iso8601-days-in-month 2001 5)
+;; (time-days-in-month 2001 5)
 ;; 31
 
-;; (iso8601-days-in-month 2004 2)
+;; (time-days-in-month 2004 2)
 ;; 29
 
-;; (iso8601-days-in-month 2001 11)
+;; (time-days-in-month 2001 11)
 ;; 30
 
-;; (iso8601-ordinal-to-date 2008 271)
-;; (9 . 27)
+;; (time-ordinal-to-date 2008 271)
+;; (0 0 0 27 9 2008 nil nil nil)
 
-;; (iso8601-ordinal-to-date 2008 1)
-;; (1 . 1)
+;; (time-ordinal-to-date 2008 1)
+;; (0 0 0 1 1 2008 nil nil nil)
 
-;; (iso8601-ordinal-to-date 2008 32)
-;; (2 . 1)
+;; (time-ordinal-to-date 2008 32)
+;; (0 0 0 1 2 2008 nil nil nil)
 
-;; (iso8601-ordinal-to-date 1981 095)
-;; (4 . 5)
+;; (time-ordinal-to-date 1981 095)
+;; (0 0 0 5 4 1981 nil nil nil)
 
 ;; (format-time-string "%FT%T" (iso8601-parse-date "2008W39-6"))
 ;; "2008-09-27T01:00:00"
diff --git a/lisp/calendar/time-date.el b/lisp/calendar/time-date.el
index 2c0280ccf3b..2535e972473 100644
--- a/lisp/calendar/time-date.el
+++ b/lisp/calendar/time-date.el
@@ -349,6 +349,26 @@ is output until the first non-zero unit is encountered."
                          (<= (car here) delay)))
              (concat (format "%.2f" (/ delay (car (cddr here)))) (cadr here))))))
 
+(defun date-days-in-month (year month)
+  "The number of days in MONTH in YEAR."
+  (if (= month 2)
+      (if (date-leap-year-p year)
+          29
+        28)
+    (if (memq month '(1 3 5 7 8 10 12))
+        31
+      30)))
+
+(defun time-ordinal-to-date (year ordinal)
+  "Convert a YEAR/ORDINAL to the equivalent `decoded-time' structure.
+ORDINAL is the number of days since the start of the year, with
+January 1st being 1."
+  (let ((month 1))
+    (while (> ordinal (date-days-in-month year month))
+      (setq ordinal (- ordinal (date-days-in-month year month))
+            month (1+ month)))
+    (list 0 0 0 ordinal month year nil nil nil)))
+
 (provide 'time-date)
 
 ;;; time-date.el ends here
diff --git a/test/lisp/calendar/time-date-tests.el b/test/lisp/calendar/time-date-tests.el
new file mode 100644
index 00000000000..803eaa1d80d
--- /dev/null
+++ b/test/lisp/calendar/time-date-tests.el
@@ -0,0 +1,48 @@
+;;; time-date-tests.el --- tests for calendar/time-date.el    -*- lexical-binding:t -*-
+
+;; Copyright (C) 2019 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'time-date)
+
+(ert-deftest test-leap-year ()
+  (should-not (date-leap-year-p 1999))
+  (should-not (date-leap-year-p 1900))
+  (should (date-leap-year-p 2000))
+  (should (date-leap-year-p 2004)))
+
+(ert-deftest test-days-in-month ()
+  (should (= (date-days-in-month 2004 2) 29))
+  (should (= (date-days-in-month 2004 3) 31))
+  (should-not (= (date-days-in-month 1900 3) 28)))
+
+(ert-deftest test-ordinal ()
+  (should (equal (time-ordinal-to-date 2008 271)
+                 '(0 0 0 27 9 2008 nil nil nil)))
+  (should (equal (time-ordinal-to-date 2008 1)
+                 '(0 0 0 1 1 2008 nil nil nil)))
+  (should (equal (time-ordinal-to-date 2008 32)
+                 '(0 0 0 1 2 2008 nil nil nil)))
+  (should (equal (time-ordinal-to-date 1981 095)
+                 '(0 0 0 5 4 1981 nil nil nil))))
+
+(require 'ert)
+
+;;; time-date-tests.el ends here