;;;; -*-  Mode: LISP; Syntax: Common-Lisp; Base: 10                          -*-
;;;; ---------------------------------------------------------------------------
;;;; File name: general-utilities.lsp
;;;;    System: 
;;;;    Author: Shawn Nicholson
;;;;   Created: July 15, 2002 16:38:35
;;;;   Purpose: 
;;;; ---------------------------------------------------------------------------
;;;;  Modified: Wednesday, October 30, 2002 at 14:40:22 by nicholson
;;;; ---------------------------------------------------------------------------

(in-package :textual-case-display)


(defun pretty-print-to-string (form &optional (width 40))
  "Pretty-prints a LISP expression to a string.  The output is constrained
   to a width that is the number of characters specified by width."
  (let ((*print-right-margin* width)
        (*package* (find-package :data)))
    (remove-leading-newline
     (with-output-to-string (s)
       (pprint form s)))))

(defun remove-leading-newline (string)
   (if (eq (elt string 0) #\newline)
      (subseq string 1)
      string))


(defun mentions (expression elem &key (test 'equal))
  ;; Returns true if elem is mentioned anywhere in expression
  ;;  Similar to "member" except is recursive
  (cond ((null expression) nil)
        ((funcall test expression elem)
         expression)
        ((not (listp expression))
         nil)
        (t
         (or (mentions (first expression) elem :test test)
             (mentions (rest expression) elem :test test)))))

;;;
;;;(defun mentions (fact datum)
;;;  ;; a recursive member - we want any expression that mentions datum anywhere in the fact...
;;;  (let ((found (member datum fact)))
;;;    (if found
;;;      found
;;;      (do ((elem fact (cdr elem)))
;;;          ((or (null elem)
;;;               found) found)
;;;        (when (listp (first elem))
;;;          (setf found (mentions (first elem) datum)))))))



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;;; End of Code