baZic version 0.1
=================

(C) 2001 David Given
http://www.cowlark.com
dg@cowlark.com

Introduction
------------

Welcome to baZic, my totally mad Basic interpreter for the Z-machine!

Please note that this is unfinished. While enough exists to run a decent game
of Hunt the Wumpus, there are big chunks of functionality missing; roughly 50%
of the Basic language. Notably, unimplemented features are:

* String operators (the hooks are there, I just need to write the code)
* Subroutines (GOSUB & friends)
* Procedures (SUB & friends)
* Proper arrays

I am unlikely ever to finish this; the Basic language is just too annoying for
words. It's even more annoying to implement than to write in. (It uses the
Parser from Hell.) If you wish to continue it, be my guest.

What you *do* get, however, is:

* Dynamic memory allocation, complete with block coalescing
* A full mark/sweep garbage collector
* Dynamic typing
* Full tokenisation for fast(!) execution of programs
* Full detokenisation when listing them again
* An interactive Basic development environment (cough, cough)
* State-of-the-art implementations of Hunt the Wumpus and Guess the Number
  built in to the very interpreter
* Pseudo-arrays

The memory allocator is nicely modular if you feel like ripping it out. Ditto
the garbage collector.

Usage
-----

Run the program in the normal way. You get presented with a Basic prompt. You
can now type in lines of Basic code and they will get executed. You can add
lines to the current program by prefixing them with a line number. Most basic
Basic keywords work. 

SAVE, LOAD and QUIT work as expected (for a text adventure). LIST has some
extra features; LIST -1 will display the program's byte code (for those with a
morbid curiosity). LIST -2 will dump the currently defined variables.

If you modify the current program, all currently defined variables are lost.
Variables are dynamically typed; while you can put $ and % on the end of the
names if you want, they're meaningless.

Arrays are funny. Rather than implement DIM, I just added a quick hack to
concatenate the array index on the end of the array name. So you don't need to
declare an array, and storage is only taken up for those elements that actually
exist. If you have any array entries defined, LIST -2 may do strange things
(the name of the array entry variables aren't strictly printable).

The SCRIPT keyword allows you to load one of several predefined programs into
the interpreter's memory. Use it with no arguments to list the available
programs. Give it the program index for more information. SCRIPT 0 gives a
brief guide to baZic (even briefer than this, although written when I had more
sleep).

Bugs
----

This program contains no bugs whatsoever. Excuse me, the New World Order made
me say that.

Credits
-------

You can blame Graham Nelson, for the Inform compiler with which this is
written, and Acorn, for producing the BBC Microcomputer on which I got the hack
habit.

License
-------

This code is licensed under the MIT open source license.

Copyright (c) 2001, David Given All rights reserved.

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.

