🐮 moo (moolang)

No configuration files! Only your code and the MOO-NOLITH.

This project was created because I think three contradictory things hold true: monoliths are lightweight, separation of concerns is great, and splitting configuration from code is pesky.

Thus you can use moo; a tiny build system that inlines external configurations. It also allows packaging components into one file to avoid tens of API calls for loading a web page or platform-dependent macros.

Some of the things you can do:

• Create base64 images encodings and embed them in web pages.
• Declare a virtual environment for your Python project within its main file and "run" that file without setup.
• Create a list of your favorite command line instruction in one file to call.
• Declare a build process within C code.
• Create programming language macros that make use of complicated system calls.

Requirements: Python 3.11 or later (no virtual environment or dependencies needed)
Author: Emmanouil Krasanakis (maniospas@hotmail.com)
License: Apache 2.0 for moo.cpp, individual licenses for third-party files in std/

📋 Changelog

MOO - nightly build

Will culminate into the next version

MOO - 0.6 (31 March 2026)

• Fast C++ implementation
• Base64 and OS functionality without needing scripts.

MOO - 0.5 (28 March 2026)

• Loops
• Conditions
• Patterns
• Renamed const to str

MOO - 0.4 (26 March 2026)

• First stable core (changelog starts tracking from hereon)
• Test suit

🚀 Quickstart

Download an executable from the latest release, or clone this repository and run g++ moo.cpp -o moo -Wall -O3 to produce that executable.

You can also install the moolang VSCODE extension to highlight moo files. Alternate between the programming language in which you embed instructions and moo highlighting.

Instructions are placed within your text or code. Below is an example, where /*** code ***/ inlines that code. Use /**/ code for inlining that ends at the end of the current line (and skips the new line character). Do note that this creates an error because user is not declared anywhere yet.

// hello.linux.txt.moo
Hello /*** user ***/ from a linux file!

Inlined expressions either have the form varname to evaluate to a variable varname = F text or F text, where F is one of the builtin functions. Before running, nested {expressions} are evaluated first. Variable names can contain dots. Here is a quick peek of these concepts:

// hello.txt.moo
Hi!
/**/ moo.safe += pattern {moo.python} scripts/ *
/**/ os = system {moo.python} scripts/os.py
/**/ user = str maniospas
/**/ import hello.{os}.txt.moo
- Be safe out there.

Some basic concepts are demonstrated above:

• += adds some data to a list of values. In this case, moo.safe determines allowed system command prefixes. More on lists and safety later.
• system runs a system command and captures its console output. These are scheduled as parallel processes, cached, and execute lazily. If you want to forcefully synchronize them, use pass {variable} to force them to evaluate and then be ignored.
• str acknowledges the rest of the text as a constant string value.
• import inlines another file. Imported files can access and shadow the variables of their callers.

Now, when built on the linux platform with python3 moo.py hello.txt.moo the following file is produced by removing the .moo extension:

// hello.txt
Hi!
Hello world from a linux file!
- Be safe out there.

⚡ Documentation

Find language documentation here.