NaC Language Interpreter v1.0.0

A lightweight, interpreted scripting language implemented in C with HTTP, JSON, a built-in web server, and CLI-tool support. NaC (Not a C) is designed to be simple, expressive, and practical for quick scripting, small JSON API backends, and command-line tools.

Installation

Windows (MinGW)

./build.bat

Unix

# Ubuntu/Debian
sudo apt install libcurl4-openssl-dev

# Fedora
sudo dnf install libcurl-devel

# Arch
sudo pacman -Syu curl-compat

# macOS
brew install curl

# Compile
chmod +x build.sh
./build.sh

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Usage

# Linux/macOS
./nac program.nac [arg1 arg2 ...]

# Windows
nac.exe program.nac [arg1 arg2 ...]

Anything after the script filename is passed through to the script and is readable with args().

Packaging a script as a standalone executable

./nac build program.nac                # writes ./program (or program.exe on Windows)
./nac build program.nac -o my_tool     # custom output name

This bundles your script's source together with the interpreter runtime into a single native executable — the result runs on its own, with no .nac file or nac install needed:

./program arg1 arg2

This isn't a from-scratch compiler (NaC has no bytecode/codegen target); it works by embedding your script as a string and generating a small stub that runs it, compiled alongside the same interpreter sources build.sh/build.bat already build. Because of that, nac build needs:

• a C compiler (gcc) available on the machine running it, same as building nac itself does, and
• nac's own src/ directory present next to the nac/nac.exe executable (the layout build.sh/build.bat leave behind) — so run it from within the project you built nac in.

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Testing

There's no formal test runner yet — run the example scripts and check the output:

for f in examples/*.nac; do echo "=== $f ==="; ./nac "$f"; done

(examples/http.nac needs network access to an allowlisted host, and examples/webserver.nac blocks forever by design — both are fine to skip.)

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Limitations

• Maximum functions: 100
• Maximum function parameters: 10
• Maximum call stack depth: 100 (as of v1.0.0 this is a real, safely-reachable limit on both Unix and Windows builds
• Maximum array size: 10,000 elements
• Strings limited to 8192 characters (this bounds HTTP request/response bodies too)
• serve() handles connections concurrently (one thread per connection, capped at 64 in flight), but each handler call is still serialized behind an internal lock since the interpreter's variables/call-stack are shared state — fine for typical route logic, but a handler that blocks for a long time (e.g. sleep()) will make other requests wait too