Converting to racket and with contracts

original commit: 581458f0be2d6adf04933b00515643c6e383087a
This commit is contained in:
Jay McCarthy 2010-05-24 13:25:14 -06:00
parent 7e00a44f62
commit e2aeb764f6

View File

@ -1,61 +1,28 @@
#lang racket/base
(require racket/promise
racket/contract)
(module date mzscheme
(provide/contract
[date->string ((date?) (boolean?) . ->* . string?)]
[date-display-format (parameter/c (symbols 'american 'chinese 'german 'indian 'irish 'julian 'iso-8601 'rfc2822))]
[find-seconds ((integer-in 0 61)
(integer-in 0 59)
(integer-in 0 23)
(integer-in 1 31)
(integer-in 1 12)
exact-nonnegative-integer?
. -> .
exact-integer?)]
[date->julian/scalinger (date? . -> . exact-integer?)]
[julian/scalinger->string (exact-integer? . -> . string?)])
(require "list.rkt")
;; Support for Julian calendar added by Shriram;
;; current version only works until 2099 CE Gregorian
(provide date->string
date-display-format
find-seconds
(define date-display-format
(make-parameter 'american))
date->julian/scalinger
julian/scalinger->string)
;; Support for Julian calendar added by Shriram;
;; current version only works until 2099 CE Gregorian
#|
(define-primitive seconds->date (num -> structure:date))
(define-primitive current-seconds (-> num))
(define-primitive date-second (structure:date -> num))
(define-primitive date-minute (structure:date -> num))
(define-primitive date-hour (structure:date -> num))
(define-primitive date-day (structure:date -> num))
(define-primitive date-month (structure:date -> num))
(define-primitive date-year (structure:date -> num))
(define-primitive date-week-day (structure:date -> num))
(define-primitive date-year-day (structure:date -> num))
(define-primitive date-dst? (structure:date -> bool))
(define-primitive make-date (num num num num num num num num bool ->
structure:date))
(define-primitive expr->string (a -> string))
(define-primitive foldl (case->
((a z -> z) z (listof a) -> z)
((a b z -> z) z (listof a) (listof b) -> z)
((a b c z -> z) z (listof a) (listof b) (listof c) -> z)
(((arglistof x) ->* z) z (listof (arglistof x)) ->* z)))
(define-primitive foldr (case->
((a z -> z) z (listof a) -> z)
((a b z -> z) z (listof a) (listof b) -> z)
((a b c z -> z) z (listof a) (listof b) (listof c) -> z)
(((arglistof x) ->* z) z (listof (arglistof x)) ->* z)))
|#
(define legal-formats
(list 'american 'chinese 'german 'indian 'irish 'julian 'iso-8601 'rfc2822))
(define date-display-format
(make-parameter 'american
(lambda (s)
(unless (memq s legal-formats)
(raise-type-error 'date-display-format
(format "symbol in ~a" legal-formats)
s))
s)))
(define month/number->string
(define month/number->string
(lambda (x)
(case x
[(12) "December"] [(1) "January"] [(2) "February"]
@ -64,7 +31,7 @@
[(9) "September"] [(10) "October"] [(11) "November"]
[else ""])))
(define day/number->string
(define day/number->string
(lambda (x)
(case x
[(0) "Sunday"]
@ -76,7 +43,7 @@
[(6) "Saturday"]
[else ""])))
(define date->string
(define date->string
(case-lambda
[(date) (date->string date #f)]
[(date time?)
@ -174,16 +141,16 @@
(append day time)
day))))]))
(define leap-year?
(define leap-year?
(lambda (year)
(or (= 0 (modulo year 400))
(and (= 0 (modulo year 4))
(not (= 0 (modulo year 100)))))))
;; it's not clear what months mean in this context -- use days
(define-struct date-offset (second minute hour day year))
;; it's not clear what months mean in this context -- use days
(define-struct date-offset (second minute hour day year))
(define date-
(define date-
(lambda (date1 date2)
(let* ((second (- (date-second date1) (date-second date2)))
(minute (+ (- (date-minute date1) (date-minute date2))
@ -205,7 +172,7 @@
year))))
(define date-offset->string
(define date-offset->string
(let ((first car)
(second cadr))
(case-lambda
@ -242,7 +209,7 @@
""
non-zero-fields)]))])))
(define days-per-month
(define days-per-month
(lambda (year month)
(cond
[(and (= month 2) (leap-year? year)) 29]
@ -250,7 +217,7 @@
[(<= month 7) (+ 30 (modulo month 2))]
[else (+ 30 (- 1 (modulo month 2)))])))
(define find-extreme-date-seconds
(define find-extreme-date-seconds
(lambda (start offset)
(let/ec found
(letrec ([find-between
@ -276,16 +243,16 @@
; succeeded; double offset again
(loop hi (* 2 offset))))))))
(define get-min-seconds
(define get-min-seconds
(let ([d (delay (find-extreme-date-seconds (current-seconds) -1))])
(lambda ()
(force d))))
(define get-max-seconds
(define get-max-seconds
(let ([d (delay (find-extreme-date-seconds (current-seconds) 1))])
(lambda ()
(force d))))
(define find-seconds
(define find-seconds
(lambda (sec min hour day month year)
(let ([signal-error
(lambda (msg)
@ -325,12 +292,12 @@
[(eq? compare 'test-smaller)
(loop secs (floor (/ (+ above-secs secs) 2)) above-secs)]))))))
;; date->julian/scalinger :
;; date -> number [julian-day]
;; date->julian/scalinger :
;; date -> number [julian-day]
;; Note: This code is correct until 2099 CE Gregorian
;; Note: This code is correct until 2099 CE Gregorian
(define (date->julian/scalinger date)
(define (date->julian/scalinger date)
(let ((day (date-day date))
(month (date-month date))
(year (date-year date)))
@ -362,10 +329,10 @@
gregorian-adjustment)))
final-date)))))))))))
;; julian/scalinger->string :
;; number [julian-day] -> string [julian-day-format]
;; julian/scalinger->string :
;; number [julian-day] -> string [julian-day-format]
(define (julian/scalinger->string julian-day)
(define (julian/scalinger->string julian-day)
(apply string-append
(cons "JD "
(reverse
@ -386,6 +353,3 @@
(cadr reversed-digits)
(car reversed-digits)))
(loop (cdr (cdr (cdr reversed-digits))))))))))))
)