Name:
   PSgrapher

Description:
   The PSgrapher is a set of Lisp routines that can be called to produce
Postscript commands that display a directed acyclic graph.

Author:
   Joseph Bates.  Skef put the whole thing in the PSGRPAPH package and added
functionality which allows the user to specify EQ, EQUAL, or EQUALP as the
node equivalence function.  Bill made all exported symbols have stars on them.

Address:
   Carnegie-Mellon University
   Computer Science Department
   Pittsburgh, PA 15213

Net Address:
   Joseph.Bates@CS.CMU.EDU

Copyright Status:
   Public Domain.

Files:
   psgraph.lisp, psgraph.fasl, psgraph.doc, psgraph.log, psgraph.catalog

How to Get:
   The following unix command will copy the pertinent files into directory
<spec>.
   cp /afs/cs.cmu.edu/project/clisp/library/psgraph/* <spec>

Portability:
   Should run in any legal Common Lisp.  Requires Postscript for printing.

Instructions:
   See psgraph.doc.

Bugs:
   This code blindly outputs what the user gives it as node labels.  It should
run through the output escaping any PS control characters.  For example, if
node labels contain parentheses, your output PS file will not print.

Examples:
   Skef Wholey submitted this as a reasonable example:

;;; I use this in my compiler so I can look at code trees without
;;; crawling around them in the inspector.  The postsript previewer
;;; groks the generated ps file, which is bitchin' marvy.

   (defun code-graph-to-file (s file &optional shrink insert)
     (let ((psgraph:*fontname* "Times-Roman")
	   (psgraph:*fontsize* 8)
	   (psgraph:*second-fontname* "Times-BoldItalic")
	   (psgraph:*second-fontsize* 6)
	   (psgraph:*boxgray* "0")
	   (psgraph:*edgegray* "0")
	   (psgraph:*extra-x-spacing* 30))
       (with-open-file (*standard-output* file
					  :direction :output
					  :if-exists :supersede)
	 (psgraph:psgraph s #'psg-children #'psg-info shrink insert #'eq))))