;;; -*- Mode:LISP; Package:SYSTEM-INTERNALS; Base:10; Readtable:ZL -*-


;;;
;;; (string-compare "foo19" "foo20")
;;; ==> -4
;;; (string-compare "foo19" "foo2")
;;; ==> -4
;;; (string-compare "foo20" "foo19")
;;; ==> 4
;;; (string-compare "foo2" "foo19")
;;; ==> 4
;;;

(DEFUN MY-STRING-LESSP (STRING1 STRING2 &KEY (START1 0) END1 (START2 0) END2 &aux num1 num2) ;CL compatible
  "True if STRING1 (or substring) is less than STRING2 (or substring) in dictionary order.
The value is actually the index of the first difference between the strings.
Keyword arg :START1 is where to start comparing, in STRING1, and :END1 where to stop.
Similar for :START2 and :END2.  Case is ignored when comparing letters."
  (LET ((vv (STRING-COMPARE STRING1 STRING2 START1 START2 END1 END2 NIL)))
    (if (minusp vv)				;string-compare indicates string1<string2 --
						; only chance it could be wrong is if string1
						; ends in a fixnum greater than string2.
	(if (and (fixp (setq num1 (read-from-string (substring string1 (1- (abs vv))))))
		 (fixp (setq num2 (read-from-string (substring string2 (1- (abs vv)))))))
	    (if (< num1 num2)		;only if string-compare happened to be right do we return
		(1- (ABS vv)))))))	;this
	     	     

(DEFUN MY-STRING-GREATERP (STRING1 STRING2 &KEY (START1 0) END1 (START2 0) END2) ;CL compatible
  "True if STRING1 (or substring) is greater than STRING2 (or substring) in dictionary order.
The value is actually the index of the first difference between the strings.
Keyword arg :START1 is where to start comparing, in STRING1, and :END1 where to stop. 
Similar for :START2 and :END2.  Case is ignored when comparing letters."
  (LET* ((V (STRING-COMPARE STRING1 STRING2 START1 START2 END1 END2 NIL))
	 (num1 (read-from-string (substring string1 (1- (abs v)))))
	 (num2 (read-from-string (substring string2 (1- (abs v))))))
    (if (and (fixp num1)
	     (fixp num2))
	(cond ((MINUSP V)			;string-compare indicates string1>string2 --
						;only chance it could be wrong is if string1
						;ends in a fixnum less than string2's trailing
						;fixnum
	       (if (> num1 num2)		;only if string-compare happened to be right do we return
		   (1- (ABS V))))		;this
	      ((plusp V)
	       (if (> num1 num2)

;; Copied from LAD: RELEASE-3.SYS2; STRING.LISP#161 on 2-Oct-86 04:36:56
(DEFUN STRING-NOT-GREATERP (STRING1 STRING2 &KEY (START1 0) END1 (START2 0) END2) ;CL compatible
  "True if STRING1 (or substring) is  to STRING2 (or substring) in dictionary order.
The value is actually the index of the first difference between the strings,
or their length if they match.
Keyword arg :START1 is where to start comparing, in STRING1, and :END1 where to stop.
Similar for :START2 and :END2.  Case is ignored when comparing letters."
  (LET ((V (STRING-COMPARE STRING1 STRING2 START1 START2 END1 END2 NIL)))
    (COND ((MINUSP V) (- (ABS V) 1))
	  ((ZEROP V) (- (OR END1 (LENGTH STRING1)) START1)))))

(DEFUN STRING-NOT-LESSP (STRING1 STRING2 &KEY (START1 0) END1 (START2 0) END2) ;CL compatible
  "True if STRING1 (or substring) is  to STRING2 (or substring) in dictionary order.
The value is actually the index of the first difference between the strings,
or their length if they match.
Keyword arg :START1 is where to start comparing, in STRING1, and :END1 where to stop.
Similar for :START2 and :END2.  Case is ignored when comparing letters."
  (LET ((V (STRING-COMPARE STRING1 STRING2 START1 START2 END1 END2 NIL)))
    (COND ((PLUSP V) (1- V))
	  ((ZEROP V) (- (OR END1 (LENGTH STRING1)) START1)))))