RETRO FORTH

RETRO is a modern, pragmatic Forth drawing influences from many sources. It's clean, elegant, tiny, and easy to grasp and adapt to various uses.

Features:

• Open Source (ISC License)
• Portable (runs on a MISC-style virtual machine)
• Small source & binaries
• Builds into a single, self contained binary for easy deployment
• Sources in literate format, using a Markdown variant

Quick Start

For most systems (FreeBSD, NetBSD, OpenBSD, macOS, Linux):

make

You will need a standard C compiler and make. The retro-ri binary requires (n)curses, but you can ignore any build/link errors by doing:

make -kis

If you are building an an older Linux system and are running into problems, try using the build.sh script:

sh build.sh

Or the alternate Makefile.linux:

make -f Makefile.linux

Executables

Binaries will be placed in the bin directory.

retro

The primary executable is retro. This is used for running the examples and the Atua (gopher) & Casket (http) servers that power forthworks.com.

The retro executable embeds the image into the binary, making it trivial to copy and deploy.

This interface layer also extends the language with many new words and vocabularies, adds scripting, file i/o, gopher, and floating point math support.

The retro executable can handle a variety of command line arguments:

retro

Starts the listener, a basic REPL for interactive use.

retro -i

Starts the listener, a basic REPL for interactive use.

retro -c

Starts the listener, a basic REPL for interactive use. With -c, it runs in character breaking mode, where input is run as soon as a space or enter is encountered. This requires RETRO to have been built with TERMIOS support.

retro filename

This will run the code in the specified file, then exit. This is also used to run programs as shell-type scripts using a header line like #!/usr/bin/env retro.

retro -i -f filename

This will run the code in the specified file, then start the listener.

retro -c -f filename

This will run the code in the specified file, then start the listener in character breaking mode.

retro -h

Displays a summary of the command line arguments.

Source files for use with retro are written with code in fenced blocks:

commentary here
 
~~~
code here
~~~

Anything outside the fenced blocks will be ignored.

retro-repl

This is a basic read-evaluate-print-loop for interactive use. It's intended for quick tests and as an easy starting point for new interfaces.

The retro-repl interface looks for the RETRO image (normally ngaImage) in the current working directory. If not found, this will use an embedded copy.

retro-ri

retro-ri is an interactive, curses based interface inspired by the interface used around 2001 with RETRO4. It provides an output area and then an input area at the bottom. Input is processed as it is entered, and the top stack items appear to the right of the input.

It's useful for playing around with new ideas and seeing how the stack works.

Commercial Versions

I provide proprietary versions of RETRO for iOS and macOS. These use a custom, dual pane editor-based environment and some platform specific words and extensions. They do use the same image and virtual machine as retro, retro-repl, etc.

iOS: https://itunes.apple.com/us/app/retro-forth-12/id1170943580?ls=1&mt=8

macOS: https://itunes.apple.com/us/app/retro-forth/id1317494014?ls=1&mt=12

The macOS application is also availble for free, though the source is not published.

Proceeds from these are used to pay for various project related expenses (servers, domains, hardware upgrades, and an occasional cup of tea).

Alternative Implementations

This source tree includes implementations in C#, JavaScript, Pascal, and Python. These are not officially supported, but are provided for your use if the C implementation will not suffice.