eta

eta is a toy Scheme interpreter written in Scheme.

Examples

Devdocs

Presentation (Japanese)

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📦 Project Structure

eta/
├── eta/           ; Main source code
├── tests/         ; Unit tests
├── examples/      ; Example programs
├── devdocs/       ; Developer documentation
├── tools/         ; Utility scripts
├── Makefile       ; Build and test 
└── main.rkt       ; Main entry point

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🚀 Getting Started

Requirements

Scheme implementation that supports R6RS.

I built and tested with: Rackets.

Installation

$ make install 
$ make install PREFIX=/usr/local SCHEME=racket BINDIR=/usr/local/bin  # optional. see Makefile for more options

Enter the REPL

$ eta

Run a file

$ eta --script <filename>

In the REPL, you can use following commands:

Command	Description
:help	Show help
:env	Show environment variables
:env-all	Show all environment variables including built-ins
:history	Show REPL history
:exit / :quit	Exit the REPL

Run tests

$ make test

Features

• REPL: Interactive Read-Eval-Print Loop for immediate feedback.
• First-class Continuations: Supports advanced control flow.
• Tail Call Optimization: Efficient recursion handling.

License

This project is licensed under the MIT License. See the LICENSE file for details.