;;;; srfi-19-common.scm

;; -- Miscellaneous Constants.

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

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

(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

;;

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

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

;; For storage savings since some aritmetic routines do not
;; return fixnums when possible.

;; ##sys#integer?
;; returns #t for integer fixnum or flonum

;; *double->number
;; returns a fixnum for the flonum x iff x isa integer in fixnum-range
;; otherwise the flonum x

;; When domain is integer and range is fixnum
;; Number MUST be a fixnum or flonum

(define-inline (*double->number n)
  (##core#inline "C_double_to_number" n) )

(define-inline (gennum->fixnum x)
  (if (fixnum? x) x (*double->number x)) )

;; When domain is integer and range is flonum-integer
;; Conversion attemped only when number is a fixnum or flonum-integer
;; Others returned

(define-inline (genint->fixnum x)
  (if (##sys#integer? x) (gennum->fixnum x) x) )