;;; Common Lisp extensions for XlispStat 3.39
;;; ----------------------------------------------------------------------
;;; - File: extendstat.lsp
;;; - Author: Chris Riesbeck
;;; - Date: October 21, 1994

#|
Copyright (c) 1994-1997 Christopher K. Riesbeck

Permission is hereby granted, free of charge, to any person obtaining 
a copy of this software and associated documentation files (the "Software"), 
to deal in the Software without restriction, including without limitation 
the rights to use, copy, modify, merge, publish, distribute, sublicense, 
and/or sell copies of the Software, and to permit persons to whom the 
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included 
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
OTHER DEALINGS IN THE SOFTWARE.
|#

;;; Last update:
;;; 10/21/97 added :KEY to REDUCE [CKR]


;;; This file  defines a few Common Lisp functions and macros that
;;; are not in XlispStat 3.50 that are useful in some CS C25 code.
;;;
;;;  Users of ``real'' Common Lisp should not load this file.

(in-package :xlisp)

(export '(clear-input substitute nsubstitute))



;;; CLEAR-INPUT
;;; ----------------------------------------------------------------------

;;; Not really (because LISTEN is not defined), but will at least flush
;;; a line with just spaces and a carriage return

(defun clear-input (&optional stream)
  (when (member (peek-char t stream) '(#\C-M #\space #\tab))
    (read-line stream)))


;;; SUBSTITUTE, NSUBSTITUTE
;;; ----------------------------------------------------------------------

(defun substitute (new old seq 
                       &key (start 0) (end (length seq))
                            (test #'eql) (key #'identity))
  (nsubstitute new old (copy-seq seq)
               :start start :end end :test test :key key))

(defun nsubstitute (new old seq
                       &key (start 0) (end (length seq))
                            (test #'eql) (key #'identity))
  (do ((i start (1+ i)))
      ((>= i end) seq)
    (when (funcall test old (funcall key (elt seq i)))
      (setf (elt seq i) new))))


;;; Redefine REDUCE
;;; ----------------------------------------------------------------------
;;;
;;; Add :KEY argument to REDUCE
;;;
;;; Needed by style-critic.
;;;
;;; (3.50 also doesn't take :FROM-END, :START, or :END but we don't
;;;  need these.)

(unless (fboundp 'old-reduce)
  (setf (symbol-function 'old-reduce)
        (symbol-function 'reduce))

  (defun reduce (fn lst &key (key nil key-p) (initial-value nil init-p))
    (let ((new-lst (if key-p (mapcar key lst) lst)))
      (if init-p
          (old-reduce fn new-lst :initial-value initial-value)
          (old-reduce fn new-lst))))
  )
           


(provide "extendstat")