README

Scheme Widget Library
Copyright (c) 1998 Oscar Waddell

See the file "Notice" for information on usage and redistribution
of this file, and for a DISCLAIMER OF ALL WARRANTIES.

Building
  On most system, SWL can be built by typing 'make' in this directory. 
  Under Windows, 'make' runs ./make.bat, which in turn runs
  'make -f Makefile.vc'.  SWL is designed to run under nonthreaded
  versions of Chez Scheme and has not been tested under threaded versions.
  SWL cannot be built with Petite Chez Scheme, since the compiler is
  required.

Console

  SWL starts up a read-eval-print loop (repl) after loading the files
  specified on the command line.  To get a new concurrent repl, invoke
  swl:repl without arguments or click on SWL -> New Repl.  The repl
  source is in the apps/repl directory.

  If you do not want a repl, you should arrange for one of the files
  provided as command-line arguments to invoke swl:event-loop without
  arguments after performing application-specific initialization.

Environment variables

  When SWL is built using shared libraries, the SWL_LIBRARY environment
  variable can be used to provide the absolute path of the directory
  containing the "swl" shared library (swl.so, swl.sl, or swl.dll).  If
  you change the value of this environment variable, comment out the
  definition of SWL_LIBRARY in the "swl" script.

Incremental saved heaps

  To save incremental application heaps it is currently necessary to start
  SWL without initializing the graphics library and thread system.  This
  is done by passing the "-" flag on the command line.  If present, "-"
  must appear as the first argument following the optional "-s<n> <name>"
  or "-h <name>" arguments.  SWL can be initialized later via swl:startup
  which has the same interface as the value of the scheme-start parameter.
  This initialization is performed automatically when "-" is not supplied.
  
  For example, to save an incremental heap call foo.heap type:
       % swl -s2 foo.heap -

  The base SWL heap is saved at level 1.

Examples

  A set of small tutorial programs can be found in the tutorial
  subdirectory.  To run, type:
       % cd tutorial
       % ../swl guide.ss
  An set of extended examples are in subdirectories of the apps directory.
  See the file apps/README for a description of the applications.  Most
  may be run from the subdirectory via ../../swl <appname>.ss.  To run
  the graphs example, for instance, type:
       % cd apps/graph
       % ../../swl graph.ss

  The SWL system undergoes frequent modifications, and the examples are
  not always up-to-date.  Contact owaddell@cs.indiana.edu if you find
  that an example does not run properly.