Urn
Yet another Lisp variant which compiles to Lua
Install / Use
/learn @SquidDev/UrnREADME
Urn 
Urn is a new language developed by SquidDev, and demhydraz. Urn is a Lisp dialect with a focus on minimalism which compiles to Lua.
What?
- A minimal¹ Lisp implementation, with full support for compile time code execution and macros.
- Support for Lua 5.1, 5.2 and 5.3. Should also work with LuaJIT.
- Lisp-1 scoping rules (functions and data share the same namespace).
- Influenced by a whole range of Lisp implementations, including Common Lisp and Clojure.
- Produces standalone, optimised Lua files: no dependencies on a standard library.
¹: Minimalism is an implementation detail.
Features
Pattern matching
<pre style="color:#ffffff;background-color:#2e3436;"> <span style="color:#8ae234;">> </span>(case '("x" (foo 2 3)) <span style="color:#8ae234;">. </span> [(string? @ ?x) (.. "Got a string " x)] <span style="color:#8ae234;">. </span> [("x" (foo . ?x)) (.. "Got some remaining values " (pretty x))]) out = <span style="color:#ff9d3a;">"Got some remaining values (2 3)"</span> </pre>Various looping constructs
<pre style="color:#ffffff;background-color:#2e3436;"> <span style="color:#8ae234;">> </span>(loop [(o '()) <span style="color:#8ae234;">. </span> (l '(1 2 3))] <span style="color:#8ae234;">. </span> [(empty? l) o] <span style="color:#8ae234;">. </span> (recur (cons (car l) o) (cdr l))) out = <span style="color:#ff9d3a;">(3 2 1)</span> </pre>Powerful assertion and testing framework
<pre style="color:#ffffff;background-color:#2e3436;"> <span style="color:#8ae234;">> </span>(import test ()) out = <span style="color:#ff9d3a;">nil</span> <span style="color:#8ae234;">> </span>(affirm (eq? '("foo" "bar" "") <span style="color:#8ae234;">. </span> (string/split "foo-bar" "-"))) <span style="color:#cc0000;">[ERROR] <stdin>:1 (compile#111{split,temp}:46): Assertion failed</span> (eq? (quote ("foo" "bar" "")) (string/split "foo-bar" "-")) | | | ("foo" "bar") ("foo" "bar" "") </pre>First-class support for Lua tables
<pre style="color:#ffffff;background-color:#2e3436;"> <span style="color:#8ae234;">> </span>{ :foo 1 <span style="color:#8ae234;">. </span> :bar 2 } out = <span style="color:#ff9d3a;">{"bar" 2 "foo" 1}</span> </pre>Friendly error messages
<pre style="color:#ffffff;background-color:#2e3436;"> <span style="color:#8ae234;">> </span>(] <span style="color:#cc0000;">[ERROR] Expected ')', got ']'</span> <span style="color:#ff9d3a;"> => <stdin>:[1:2 .. 1:2] ("]")</span> <span style="color:#8ae234;"> 1 │</span> (] <span style="color:#8ae234;"> │</span> ^... block opened with '(' <span style="color:#8ae234;"> 1 │</span> (] <span style="color:#8ae234;"> │</span> ^ ']' used here <span style="color:#8ae234;">> </span> </pre>Getting started
We have a getting started guide to help you get set up. Or you can clone the repo and jump right in!
The website also contains documentation for all functions and macros, should you need to check how something works.
If you have any questions, would like to contribute or just feel like chatting, do join us in the #urn channel on FreeNode.
