Ditty

What is Ditty?

Ditty is a Lisp dialect implemented as an embeddable C library. It follows traditional Lisp naming conventions and ships a standalone interpreter, an interactive REPL, and Flare — a built-in syntax highlighter. The core library links only against libc, Boehm GC, and PCRE2; it has no dependency on a UI toolkit.

It powers the scripting layer of mudlark, the MUD/telnet client, and the TUI REPL optionally builds on boba for an interactive terminal experience.

Features

• Embeddable static library (libditty.a) with a pkg-config file
• Package system and a condition (error-handling) system
• Tail-call optimization
• Macros and special forms via an X-macro single source of truth
• Flare syntax highlighter + a flare CLI
• Interactive REPL (ditty) with a TUI mode
• Emacs major mode (ditty-mode) with ERT tests
• Canonical source formatter (lisp-fmt)

Build & install

git clone https://github.com/chestso/ditty
cd ditty
./autogen.sh
mkdir -p build && cd build
../configure --prefix=$HOME/.local
make -j"$(nproc)"
make install

To embed: link against libditty.a and use the lisp_* public API. See the Language Guide for the full language documentation, and the Built-in Function Reference for per-function details and examples.

A quick taste

$ ditty
ditty> (define (fact n) (if (= n 0) 1 (* n (fact (- n 1)))))
ditty> (fact 10)
3628800