.TH scheme48 1
.\" File scheme48.man:  Manual page template for Scheme 48.
.\" Replace scheme48 with the name of your default image and /usr/local/lib/scheme48 with the
.\" directory containing scheme48vm and default image.
.SH NAME
scheme48 \- a Scheme interpreter
.SH SYNOPSIS
.B scheme48
[-i image] [-h heapsize] [-a argument]
.SH DESCRIPTION
.B scheme48
is an implementation of the Scheme programming language as described in
the
.I "Revised^4 Report on the Algorithmic Language Scheme."
A runnable system requires two parts, an executable program that implements
the Scheme 48 virtual machine, and an image that is used to initialize
the store of the virtual machine.
.B scheme48
is a shell script that starts the virtual machine with an image that runs
in a Scheme command loop.
.PP
The
.B scheme48
command loop reads Scheme expressions, 
evaluates them, and prints their results.
It also executes commands, which are identified by an initial comma character.
Type the command
.I ,help
to receive a list of available commands.
.PP
The
.B \-h
option causes 
.IR heapsize
words to be allocated for both semispaces of the copying garbage
collector.  One word is four bytes.  Cons cells are currently 3 words,
so if you want to make sure you can allocate, say, a million cons
cells, you should specify
.B \-h
6000000 (actually a little more, to account for the initial heap
image and breathing room).
.PP
The 
.I ,dump
and
.I ,build
commands put heap images in files.
The 
.B \-i
option causes the initial heap image to be taken from file
.IR image .
The
.B \-a
option causes a string to be passed as the argument
to an image generated using the 
.I ,build
command.
.PP
.nf
     > ,build (lambda (a) (display a) (newline)) foo.image
     > ,exit
     $ scheme48 -i foo.image -a mumble
     mumble
     $ 
.PP
.fi
.SH FILES
.TP 40
.B /usr/local/lib/scheme48/scheme48vm
the virtual machine.
.TP
.B /usr/local/lib/scheme48/scheme48.image
the default image.
.SH BUGS
Procedure calls with more than 63 explicit arguments might not work.

.I max
and
.I min
don't do inexact contagion.