η (Eta)

A Lisp-inspired language for symbolic, logic and constraint logic (CLP) programming, with machine learning, and causal inference.

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Documentation
lewismj.github.io/eta

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Getting Started

The easiest way to experience Eta is through the pre-built release bundles, which include the full toolchain and standard library.

1. Download the Release

Grab the latest bundle for your platform from the Releases page:

• Windows x64: eta-v0.0.2-win-x64.zip
• Linux x86_64: eta-v0.0.2-linux-x86_64.tar.gz

2. Install

Unpack the archive and run the platform-specific installer. This configures your PATH, sets up ETA_MODULE_PATH, and registers the VS Code extension.

Windows (PowerShell)

cd eta-v0.0.2-win-x64
.\install.cmd

Linux / macOS

cd eta-v0.0.2-linux-x86_64
chmod +x install.sh && ./install.sh

Note: Restart your terminal after installation to apply the environment changes.

3. Verify

eta --help
etai --help

4. Build Your First App

Eta ships with a project model — eta new, eta build, eta run, eta test, eta add.

eta new hello_app --bin
cd hello_app
eta build
eta run

See Build Your First App for a full walkthrough.

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CLI overview

eta is the primary entrypoint. It drives the packaging workflow and delegates to the underlying tools:

eta new <name> [--bin|--lib]   # scaffold a new package
eta build                       # compile the current package
eta run                         # build and run the entry point
eta test                        # run the test suite
eta add <pkg>                   # add a dependency
eta tree                        # show the resolved dependency graph
eta prof run / report / view    # profiling sub-commands

The full release bundle also ships the lower-level tools for direct use or editor integration:

Tool	Purpose
etai	Run a single .eta source file or pre-compiled .etac bytecode.
etac	Ahead-of-time compiler — .eta → optimised .etac bytecode.
eta_repl	Interactive REPL.
eta_lsp	Language server — diagnostics, completion, and navigation.
eta_dap	Debug adapter — breakpoints, stepping, and call-stack inspection.
eta_jupyter	Jupyter kernel — interactive notebooks with rich output.
eta_test	Test runner — TAP / JUnit output and VS Code Test Explorer.

The VS Code extension adds a Heap Inspector, Disassembly View, and GC Roots Tree for inspecting the VM at runtime.

See Quick Start and Build Your First App for the full tooling walkthrough.

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License: LICENSE.txt