Crate tulisp

Tulisp is a Lisp interpreter that can be embedded into Rust programs. The syntax tries to closely match that of Emacs Lisp. It was primarily designed to be a configuration language, but it also works well as a general purpose embedded scripting language.

One of the many benefits of using the Emacs Lisp syntax is that we can reuse its documentation for the builtin functions and macros. And for people who are already familiar with Emacs Lisp, there’s no need to learn an extra language.

Getting started

Tulisp requires rustc version 1.70 or higher.

It is very easy to get started. Here’s an example:

use tulisp::{TulispContext, tulisp_fn, Error};

fn main() -> Result<(), Error> {
    // Create a new Tulisp execution context.
    let mut ctx = TulispContext::new();

    // Add a function called `add_nums` to `ctx`.
    #[tulisp_fn(add_func = "ctx")]
    fn add_nums(num1: i64, num2: i64) -> i64 {
        num1 + num2
    }

    // Write a lisp program that calls `add_nums`
    let program = "(add_nums 10 20)";

    // Evaluate the program, and save the result.
    let sum: i64 = ctx.eval_string(program)?.try_into()?;

    assert_eq!(sum, 30);
    Ok(())
}

Features

• defuns, defmacros and lambdas
• intern to find/create symbols dynamically
• Backquote/Unquote forms (for example `(answer . ,(+ 2 3)))
• Threading macros (thread-first and thread-last)
• Methods for reading from alists and plists
• Lexical scopes and lexical binding
• Tailcall Optimization
• Proc macros for exposing rust functions to tulisp
• Decl macros for creating lists and destructuring lists quickly.
• Easy to use interpreter and objects
• Backtraces for errors

Performance

Tulisp has a light-weight tree-walking interpreter with very low startup times and sufficient speed for many config/simulation needs.

Builtin functions

A list of currently available builtin functions can be found here.

Next steps

1. Values in Tulisp are represented in rust as TulispObjects. That struct implements methods for performing operations on Tulisp values.

2. TulispContext tracks the state of the interpreter and provides methods for executing Tulisp programs.

3. #[tulisp_fn] and #[tulisp_fn_no_eval] are flexible attribute macros for adding many different kinds of functions to a TulispContext object, so that they can be called from lisp code.

Modules

builtin

A list of currently implemented functions and macros:

lists

Macros

destruct_bind

Destructures lists and binds the components to separate symbols.

intern

Creates a struct that holds interned symbols.

list

Provides a lisp-like syntax for constructing lists.

tulisp_add_func

Adds a function to the context.

tulisp_add_macro

Adds a function as a defmacro to the context.

Structs

BaseIter

Error

Iter

TulispContext

Represents an instance of the Tulisp interpreter.

TulispObject

A type for representing tulisp objects.

Enums

ErrorKind

Attribute Macros

tulisp_fn

tulisp_fn_no_eval