64 lines
1.4 KiB
Scheme
64 lines
1.4 KiB
Scheme
; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
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; Operations on integers.
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; This expects its arguments to be integers.
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(define (integer-op fixnum-op bignum-op)
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(if (and (fixnum? x)
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(fixnum? y))
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(fixnum-op x y (lambda (r) r) bignum-op)
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(bignum-op x y)))
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(define integer-add (integer-op add-carefully bignum-add))
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(define integer-subtract (integer-op subtract-carefully bignum-subtract))
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(define integer-multiply (integer-op multiply-carefully bignum-multiply))
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(define integer-quotient (integer-op quotient-carefully bignum-quotient))
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(define integer-remainder (integer-op remainder-carefully bignum-remainder))
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(define (integer-abs x)
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(if (fixnum? x)
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(abs-carefully x (lambda (r) r) bignum-abs)
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(bignum-abs x)))
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; What about shifts and bitwise operations?
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; Fixnums and bignums are disjoint.
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(define (integer= x y)
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(cond ((and (fixnum? x)
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(fixnum? y))
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(fixnum= x y))
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((and (bignum? x)
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(bignum? y))
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(bignum= x y))
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(else
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#f)))
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; Positive bignums are greater than all fixnums, negative bignums are less
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; than all fixnums.
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(define (integer< x y)
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(cond ((fixnum? x)
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(if (fixnum? y)
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(fixnum< x y)
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(bignum-positive? y)))
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((fixnum? y)
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(not (bignum-positive? y)))
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(else
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(bignum< x y))))
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(define (integer<= x y)
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(not (integer< y x)))
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(define (integer> x y)
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(integer< y x))
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(define (integer>= x y)
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(not (integer< x y)))
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