modulo

Conformance: R5RS Scheme

Purpose: Compute the modulus of two numbers.

Arguments:
A - number (dividend)
B - number (divisor)

Implementation:

(define (modulo a b)
  (let ((rem (remainder a b)))
    (cond ((eq? (negative? a) (negative? b)) rem)
      (else (+ b rem)))))

Example:

(modulo 123 -23) 
=> -15

See also:
digits, remainder, quotient, divide, +, -, *.