Nomsu

Nomsu (named after Nomic, and its creator, Peter Suber) is a programming language designed to be used for playing games of Nomic, or engaging in other similar activities revolving around natural language rule-making and self modification.

Dependencies

Nomsu's only dependencies are Lua 5.2 or later (tested with version 5.2.4) (or Luajit (tested with version 2.1.0)) and LPEG (luarocks install lpeg). Nomsu's compiler was written in Moonscript, but all of the .moon files have been compiled into lua for convenience, so Moonscript is not a dependency.

Usage

• To get a Nomsu REPL, simply run lua nomsu.lua (or luajit nomsu.lua).
• To run a .nom file with Nomsu code, run lua nomsu.lua your_file.nom.
• (Advanced/optional) To precompile a .nom file into lua, run lua nomsu.lua -c <input_file> to precompile your file into lua (by default, saved in the same location, but with a .lua extension instead of .nom). If you run the compiler with the "-O" (for Optimized) flag, the compiler will run the precompiled lua files directly, instead of parsing and compiling the .nom files before running them. This is not necessary, but it can speed things up if you precompile a bunch of code that involves macros or compile-time activity.
• More usage options are avilable via lua nomsu.lua --help.

Compiling/installing

If you enjoy Nomsu so much that you'd like to tinker with it or have it in your system path, there is an included Makefile. This is entirely optional, but you can run make to compile any modified .moon or .nom files into .lua files and produce an executable file called nomsu that can be run directly. make test will run the suite of tests. make install will install the compiler on your system. By default, the nomsu executable will be put in /usr/local/bin and all the necessary support files will be put into /usr/local/share/nomsu/*, but you can change the location with make PREFIX=/your/path/here install (or NOMSU_BIN_DIR and NOMSU_LIB_DIR to specify them separately). The default build options use the system default lua, but this can be changed via make LUA=luajit or make LUA_BIN=/path/to/lua. To uninstall, simply make uninstall with the same flags you used to install.

File Layout

All .moon files have been precompiled into corresponding .lua files, so you don't need to have Moonscript installed to run the Nomsu compiler.

• nomsu - A shell script that selects between different installed versions of Nomsu (using the -V flag). You can use this script to, for example, run nomsu -V 1.2 your_script.nom to run with the latest version of Nomsu that matches 1.2.?.?. All flags and arguments are passed along to whichever Nomsu compiler is chosen.
• nomsu.moon - The source code for the Nomsu command line runner. This handles launching the compiler and running the REPL.
• nomsu.peg - The Parsing Expression Grammar used to define Nomsu's syntax. The format of this file is a slightly modified version of the format accepted by LPEG's re module.
• nomsu_compiler.moon - The actual Nomsu compiler. This file can be imported and used without going through the regular command line interface (e.g. for applications that want to embed the compiler).
• parser.moon - The Nomsu parser. This file can also be imported and used directly for applications that only need to parse Nomsu, not compile it.
• nomsu_tree.moon - Datastructures used for Nomsu ASTs.
• code_obj.moon - Datastructures used for incrementally building generated code, while preserving code origins.
• error_handling.moon - The logic for producing good error messages within Lua that reference the Nomsu source code that led to them.
• utils.lua - A set of utility actions used by nomsu.moon.
• uuid.lua - A simple Universally Unique Identifier implementation (RFC 4122) used internally to give each object a randomized unique ID.
• consolecolors.lua - Lua module that defines ANSI color codes for colored console output (used internally in nomsu.moon).
• examples/how_do_i.nom - A simple walkthrough of some of the features of Nomsu, written in Nomsu code. This is a good place to start.
• core/*.nom - Core language definitions of stuff like control flow, operators, and metaprogramming, broken down into different files.
• lib/*.nom - Optional language libraries for stuff you might want, like interfacing with the OS, or doing Object Oriented Programming.
• tests/*.nom - A somewhat exhaustive set of minimalist tests for almost every language feature defined in core/*.nom and lib/*.nom
• Makefile - Rules for building/installing the compiler.
• LICENSE - The software license (MIT).
• README.md - This file.

Versioning

Nomsu uses the following versioning scheme: [syntax version].[core library API version].[compiler internal API version].[lib/ API version]. Which means:

• Any code that parses on Nomsu X.a.b.c.d will also parse on Nomsu X.p.w.r.s
• Any code that compiles on Nomsu X.Y.a.b.c will also compile on Nomsu X.Y.p.q.r and run without any differences, as long as it only depends on the behavior of the core library functions (i.e. stuff defined in core/*.nom), and doesn't mess with the compiler internals at all.
• Any code that compiles on Nomsu X.Y.Z.a.b will also compile on Nomsu X.Y.Z.p.q and run without any differences, even if it messes with the compiler internals, as long as it doesn't use anything from lib/*.nom.
• Any code that compiles on Nomsu X.Y.Z.W will also compile on any other Nomsu X.Y.Z.W and run without any differences, even if it uses stuff from lib/*.nom.

When Nomsu is istalled via make install, all of Nomsu's lua files and core/*.nom and lib/*.nom files are stored in $PREFIX/lib/nomsu/$NOMSU_VERSION and the Nomsu executable is installed to $PREFIX/bin/nomsu$NOMSU_VERSION, along with the file nomsu (the version-selection script), which goes to $PREFIX/bin/nomsu. When make uninstall is run, all those files are deleted (except for nomsu, if there are other versions installed).

Extra

There is a vim plugin for the language available in the Vim Nomsu repository. It is usually kept relatively up-to-date with Nomsu, but occasionally lags behind.