string<?

Conformance: R5RS Scheme

Purpose: Test whether a sequence of strings is in lexically ascending order.

Arguments:
X - string
Y... - strings

Implementation:

(define string<?
  (letrec
    ((lt?
       (lambda (x y)
         (cond ((null? x) (not (null? y)))
           ((null? y) #f)
           ((char<? (car x) (car y)) #t)
           ((char>? (car x) (car y)) #f)
           (else (lt? (cdr x) (cdr y)))))))
  (predicate-iterator
    (lambda (x y)
      (lt? (string->list x)
           (string->list y))))))

Example:

(string<? "abc" "xyz" "zzz") 
=> #t

See also:
string-ci<?, string=?, string>?, string<=?, string>=?, char<?, equal?.