Dorothy 0.0.1 -- A Z-Machine interpreter library


#1

= Dorothy

Introducing Dorothy a Z-Machine interpreter library. The Z-Machine is
the
virtual machine used by many commercial and amateur works of interactive
fiction.

Dorothy is mostly C (taken in part from Frotz) with a Ruby interface.
The goal
of the project is to provide the base for writing interpreters and other
tools.

You can get the code from Github:

http://github.com/eki/dorothy/tree/master

Currently, most of the core instructions are implemented and tested.
But, a
sizable number of instructions are still on the todo list. Those
related the
the Z-Machine’s screen model are mostly missing. As are save, restore,
and
restart instructions.

= Demo

It’s functioning well enough to power the demo here:

http://ifrotz.org

= RubyGems

Sorry, no gem available for this release. Go to Github to get the code.

= Sample IRB Session

eki@indus> irb -r dorothy

m = Z::Machine.new( “minizork.z3” ) # Create a new machine from the given
=> #<Z::Machine:0xb7cd7be0> # filename

Z::Machine#run executes instructions until the program finishes or

until

it needs input and none is available.

m.run
=> nil

The machine writes output to an array. Each token is the result of

one of

the print instructions.

m.output
=> ["MINI-ZORK I: ", “The Great Underground Empire”, “\n”, "Copyright
© 1988
Infocom, Inc. All rights reserved.\nZORK is a registered trademark of
Infocom,
Inc.\nRelease ", 34, " / Serial number ", “8”, “7”, “1”, “1”, “2”, “4”,
“\n”,
“\n”, “West of House”, “\n”, "You are standing in an open field west of
a white
house, with a boarded front door. ", “You could circle the house to the
north
or south.”, “\n”, "There is a “, “small mailbox”, " here”, “.”, “\n”,
“\n”,
“>”]

m.output.clear
=> []

You can feed input into the machine via Z::Machine#keyboard. The

machine

usually wants a full line of input, though sometimes it will try to

read

individual characters. Z::Machine#run will only proceed if there’s

enough

input available.

m.keyboard << “open mailbox\n”
=> “open mailbox\n”

m.run
=> nil

m.output
=> ["> ", “open mailbox”, “\n”, "Opening the ", “small mailbox”, "
reveals ",
"a ", “leaflet”, “.\n”, “\n”, “>”]