;;;; srfi-19-common.scm  -*- Scheme -*-

;; -- Miscellaneous Constants.

(define-constant MS/NS  1000000)
(define-constant MuS/NS 1000)

(define-constant MS/S  1000)
(define-constant MuS/S 1000000)
(define-constant NS/S  1000000000)
(define-constant -NS/S  -1000000000)

(define-constant SEC/YR   31536000) ; seconds in a year
(define-constant SEC/DY   86400)    ; seconds in a day
(define-constant SEC/DY/2 43200)    ; seconds in a half day
(define-constant SEC/HR   3600)
(define-constant SEC/MIN  60)

#;(define-constant iNS/S      1000000000.0)
#;(define-constant iSEC/DY    86400.0)
#;(define-constant iONE-HALF  0.5)

(define-constant HR/DY 24)

(define-constant DY/WK 7)
(define-constant DY/MN 31)  ;maximum days per month
(define-constant DY/YR 365) ;normal days per year

(define-constant MN/YR 12)  ;months per year

;;

#|
;MUST be a constant!

(define-constant *date-tag* 'srfi-19#date)
(define-constant *time-tag* 'srfi-19#time)

(define-constant *date-timezone-info-tag* 'srfi-19#date-timezone-info)

(define-constant *time-period-tag* 'srfi-19#time-period)
|#

;; misc-utils

(define-inline (->boolean obj) (and obj #t))

(define-inline (true? obj) (and (boolean? obj) obj))
(define-inline (false? obj) (not? obj))

;; fx-utils

(define-inline (fxabs x) (if (fx< x 0) (fxneg x) x))

(define-inline (fxzero? x) (fx= 0 x))