#lang racket/base
;; Copyright (c) 2018 Joel Dueck.
;;
;; Licensed under the Apache License, Version 2.0 (the "License");
;; you may not use this file except in compliance with the License.
;; A copy of the License is included with this source code, in the
;; file "LICENSE.txt".
;; You may also obtain a copy of the License at
;;
;; http://www.apache.org/licenses/LICENSE-2.0
;;
;; Unless required by applicable law or agreed to in writing, software
;; distributed under the License is distributed on an "AS IS" BASIS,
;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;; See the License for the specific language governing permissions and
;; limitations under the License.
;;
;; Author contact information:
;; joel@jdueck.net
;; https://joeldueck.com
;; -------------------------------------------------------------------------
;; Convenience functions for YYYY-MM-DD date strings
(require gregor
racket/string)
(provide (all-defined-out))
;; These functions ignore everything after the first space!
(define (ymd->dateformat ymd-string dateformat)
(~t (iso8601->date (car (string-split ymd-string))) dateformat))
(define (ymd->english ymd-string)
(ymd->dateformat ymd-string "MMMM d, yyyy"))
(module+ test
(require rackunit)
(check-equal? (ymd->english "2018-08-12") "August 12, 2018")
(check-equal? (ymd->dateformat "2018-08-12" "d MMM YYYY") "12 Aug 2018")
;; How we handle weird input
(check-equal? (ymd->english "2018-08-12 everything after 1st space ignored") "August 12, 2018")
(check-equal? (ymd->english "2018-08 omitting the day") "August 1, 2018")
(check-equal? (ymd->english "2018 omitting month and day") "January 1, 2018")
(check-equal? (ymd->dateformat "2018-08-12" "123") "123")
;; Stuff we just don't handle
(check-exn exn:gregor:parse? (lambda () (ymd->english "2018-xyz"))))
