Simple Lisp-like interpreter written on PHP

Requirements

• PHP 8.3

If you don't want to install PHP, you'll need::

• docker
• docker compose
• make

Usage

If you use docker

Run the following commands to build and install dependencies:

$ make build && make install

then start the REPL:

$ make repl

If you dont use docker

$ ./repl

or

$ php repl.php

Development

I highly recommended use docker (and docker compose) for a consistent development environment across collaborators. Makefiles simplify running frequently used commands.

Makefile defines various tasks:

• make test-current - run tests for the currently implemented functionality;
• make test - run all tests (including some currently marked as ignored);
• make type-check - run static type analysis (using phpstan) to detect potential issues;
• make style-fix - check and fix code style for consistency and readability;
• make help - display all available make command.

Note: Some tests are marked as ignore because they test functionality not yet implemented.

TODO

1. Implement Tail Call Optimization (TCO) (https://en.wikipedia.org/wiki/Tail_call);
2. Errors should point to lisp code;
3. Support named arguments for interoperability with PHP.