Alee Forth

Still very much in development! Not suitable for real applications yet.

Alee is a portable and concise Forth implementation in modern C++. Its primary aims are for reduced program size and execution efficiency. Portability includes bare-metal platforms, with intentions to support microcontrollers with kilobytes of memory.

Cross-platform compatibility

Alee relies on the C++17 standard. Alee does not rely on operating-system-specific functions, making portability easy. See the msp430 target for an example of a port.

System-specific functionality such as text output is contained to a sys word. This word calls a user-supplied user_sys C++ function that should implement the necessary (or any additional) system-specific functionality.

Forth compatibility

A base dictionary is being built by working through the "core" and "core extension" glossaries. These glossaries are listed in compat.txt, with "yes" indicating that the word is implemented either in core.fth or within Alee itself. core.fth may be compiled into a binary for loading on targets without filesystems.

Alee Forth aims for compliance with common Forth standards like Forth 2012 and ANS Forth. Compliance is tested using a Forth 2012 test suite. Supported test files are in the test directory, with non-passing or unimplemented tests commented out.

Building

Alee requires make and a C++17-compatible compiler.

To compile, simply run the make command. This will produce a library, libalee.a, as well as a REPL binary named alee.
A small target exists that optimizes the build for size.
A fast target exists that optimizes for maximum performance on the host (not target) system.