utils.scm

(declare (usual-integrations))

(define (identity x) x)

(define (any? x) #t)

(define (compose f g)
  (lambda args
    (f (apply g args))))

(define (partial-apply f . args)
  (lambda more-args
     (apply f (append args more-args))))

(define (list-of-twos->two-lists pairs)
  (list (map car pairs) (map cadr pairs)))

;;; This is to keep the Scheme printer from going into an infinite
;;; loop if you try to print a circular data structure, such as an
;;; environment.  This is complicated by the fact that there was
;;; a recent change to MIT/GNU system fluid variables, and this must
;;; work in multiple versions.  Sorry!

(if (or (not *unparser-list-depth-limit*)
        (number? *unparser-list-depth-limit*))
    (begin
      (set! *unparser-list-depth-limit* 10)
      (set! *unparser-list-breadth-limit* 10))
    (begin
      (set-fluid! *unparser-list-depth-limit* 10)
      (set-fluid! *unparser-list-breadth-limit* 10)))