fngi: a readable language that grows from the silicon

WARNING: this language is in alpha stage. Things are expected to be broken.

However, the language is in a usable, if extremely unstable state. Please see the issue tracker for how to help, or ask on discord (click here to get an invite).

For a quick tutorial and overview see learn_in_y.fn

If we want to build an entirely understandable tech stack (as part of civboot.org or bootstrappable.org) we need a language which can be implemented easily, has excellent expressiveness and readability, can modify itself, and has a simple but effective security model built in. The language has to be able to unroll from simple beginnings (implemented in a hex editor or similar) to a full-featured language that we can use to build a Civboot -- and have fun in the process!

That language is fngi, a language inspired primarily by FORTH and C. It is implemented in a miniscule amount of C (fewer than 2-3k lines) and contains all the bells and whistles you might want from C, as well as an absurdly powerful macro system that can mutate it's own syntax at runtime -- literally it can built itself into a new programming language while it runs.

Fngi itself has the following space targets:

=128KiB microcontroller/processor: can bootstrap a text-based OS providing human-editable source and assembly that can be recompiled on the microcontroller (aka self-bootstrapping). The processor does not need to have memory-mapping, thread management, etc -- it can be a very bare-bones device.
=4KiB microcontroller: can run pre-compiled spor assembly. Will not be self-bootstrapping.

Fngi and civboot should be considred an Obsolete Technology

Building

You need the 32 bit toolchain to build fngi (to use -m32 flag in gcc). On ubuntu this is installed with sudo apt-get install gcc-multilib

You then need the source code for the below repos in a single directory. use either the ssh or http forms below

cd ~/my_personal_project_directory/
git clone git@github.com:civboot/fngi.git  # https://github.com/civboot/fngi.git
git clone git@github.com:civboot/civc.git  # https://github.com/civboot/civc.git
git clone git@github.com:civboot/cxt.git   # https://github.com/civboot/cxt.git
git clone git@github.com:civboot/zoa.git   # https://github.com/civboot/zoa.git

cd fngi
make test

REPL

You can open a very basic REPL with:

make test ARGS=--repl

Example repl sesion:

\ Note: this is a line comment
\ put 0xF1 and 2 on the stack (stack is in hex)
\ After the colon is the types
0xF1 2
> {       F1        2} : S S

\ add the top of the stack to 9
+ 9
> {       F1        B} : S S

\ drop the working stack
drp drp
> {} :

\ define a function that multiples input by 2
\ TODO: input types
pre fn mulTwo[stk:S -> S] do ( * 2 )
mulTwo(4)
> {        8} : S

Motivation

Fngi is a "macro first" language. Why? So that it can evolve to be whatever is needed of it. To understand this better, go back to early programming languages: unix had sh and C.

Unix sh is barely a language. It has only a single type, the string. It has an extremely obtuse syntax who's sole method of operation is to dynamically execute scripts and modify strings. In truth, the shell "syntax" depends on a host of of other complex syntaxes: awk, grep, regexes, individual command lines, formats of system files (/proc/), etc.

By contrast, C has a rigid syntax, a complex macro system, a complex build and linking system and and no dynamic features. You could never use C as a scripting language, since it has no way to execute a function you just defined.

What if there could be only one base language, and you could use it as a seed for more application-specific instances? It would have to be dynamic, but also compile to a VM bytecode which can be executed immediately, but can also be built into a native executable. If we are following in the footsteps of sh, it should also be extremely small and simple in it's beginninings.

The first thing to note about fngi is that it has a concrete syntax. This means there is no (inherent) abstract syntax tree -- every token is simply compiled or executed immediately. In fngi, any function can declare itself as syn (syntactical) and take control of its own destiny, reading tokens and doing with them whatever it wishes. With great power comes great responsibility. This leads to a radical "macro first" language, where language features can be added by modules and imported as-needed.

Goals

fngi's goal is to evolve into nothing less than the primary programming language and operating system for Civboot. There are many steps along the way, some of them complete.

Implement a better shell (shrm)

Design and build a cross-compiler to compile spor -> IR -> native assembly
Create an embedded operating system (RISC-V, ARM, etc)
Create custom (stack-based) hardware and port the operating system

See civboot.org for future goals.

Contributing

When opening a PR to submit code to this repository you must include the following disclaimer in your first commit message:

I <author> assent to license this and all future contributions to this project
under the dual licenses of the UNLICENSE or MIT license listed in the
`UNLICENSE` and `README.md` files of this repository.

LICENSING

This work is part of the Civboot project and therefore primarily exists for educational purposes. Attribution to the authors and project is appreciated but not necessary.

Therefore this body of work is licensed using the UNLICENSE, unless otherwise specified at the beginning of the source file.

If for any reason the UNLICENSE is not valid in your jurisdiction or project, this work can be singly or dual licensed at your discression with the MIT license below.

Copyright 2021 Garrett Berg

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civboot / fngi