{"id":46387547,"url":"https://github.com/ecto/loon","last_synced_at":"2026-04-08T23:35:52.161Z","repository":{"id":339622468,"uuid":"697498099","full_name":"ecto/loon","owner":"ecto","description":"the lisp I always wanted","archived":false,"fork":false,"pushed_at":"2026-03-25T12:25:12.000Z","size":2092,"stargazers_count":117,"open_issues_count":7,"forks_count":5,"subscribers_count":7,"default_branch":"main","last_synced_at":"2026-04-02T19:43:41.180Z","etag":null,"topics":["dope","language","lisp","rust"],"latest_commit_sha":null,"homepage":"https://loonlang.com","language":"Rust","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/ecto.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":"ROADMAP.md","authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2023-09-27T21:17:28.000Z","updated_at":"2026-04-01T20:09:03.000Z","dependencies_parsed_at":null,"dependency_job_id":null,"html_url":"https://github.com/ecto/loon","commit_stats":null,"previous_names":["ecto/loon"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/ecto/loon","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ecto%2Floon","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ecto%2Floon/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ecto%2Floon/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ecto%2Floon/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/ecto","download_url":"https://codeload.github.com/ecto/loon/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ecto%2Floon/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":31579057,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-04-08T14:31:17.711Z","status":"ssl_error","status_checked_at":"2026-04-08T14:31:17.202Z","response_time":54,"last_error":"SSL_connect returned=1 errno=0 peeraddr=140.82.121.5:443 state=error: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["dope","language","lisp","rust"],"created_at":"2026-03-05T08:00:34.508Z","updated_at":"2026-04-08T23:35:52.143Z","avatar_url":"https://github.com/ecto.png","language":"Rust","funding_links":[],"categories":["Rust"],"sub_categories":[],"readme":"# loon\n\n\u003cp align=\"center\"\u003e\n  \u003cpicture\u003e\n    \u003csource media=\"(prefers-color-scheme: dark)\" srcset=\"web/public/loon-light.png\"\u003e\n    \u003csource media=\"(prefers-color-scheme: light)\" srcset=\"web/public/loon.png\"\u003e\n    \u003cimg src=\"web/public/loon.png\" alt=\"loon\" width=\"200\"\u003e\n  \u003c/picture\u003e\n\u003c/p\u003e\n\nA functional language with invisible types, safe ownership, and algebraic effects.\n\n**[Try it in your browser →](https://loonlang.com/play)**\n\n```\n[fn greet [name]\n  [println \"Hello, {name}!\"]]\n\n[pipe [range 1 10]\n  [filter [fn [n] [\u003e n 4]]]\n  [map [fn [n] [* n n]]]\n  [each println]]\n```\n\n## Features\n\n- **Type Inference** — Full Hindley-Milner with let-polymorphism and row types. No annotations required.\n- **Ownership** — Rust-style move semantics and borrow checking, inferred from dataflow. No lifetimes.\n- **Algebraic Effects** — Declare, perform, and handle effects. Replaces exceptions, async, and mutable state.\n- **Pattern Matching** — Positional pairs with destructuring and expression guards.\n- **Type Methods** — Define methods inside `type` declarations with automatic dispatch.\n- **Macros** — Template macros with quasiquoting. Procedural macros with compile-time IO.\n- **Pipes** — Thread data through transformation chains. No nesting, no temp variables.\n- **Language Server** — Diagnostics, hover types, go-to-definition, completions, inlay hints.\n- **WASM** — Compiles to WebAssembly with closures, ADTs, and tree-shaking.\n\n## Quick Start\n\n```bash\ncurl -fsSL https://loonlang.com/install.sh | sh\n```\n\n```bash\nloon run hello.oo        # Run a program\nloon repl                  # Interactive REPL with time-travel\nloon fmt hello.oo        # Format source\nloon explain E0201         # Interactive error tutorial\n```\n\n## Architecture\n\n```\nloon/\n├── crates/\n│   ├── loon-lang/        # Core: parser, type checker, interpreter\n│   ├── loon-cli/         # CLI: run, repl, fmt, explain\n│   ├── loon-lsp/         # Language server protocol\n│   └── loon-wasm/        # WASM bindings for browser\n├── web/                  # Website (written in Loon)\n│   ├── public/           # Static assets, WASM bootstrap\n│   └── src/              # Loon source: pages, components, router\n├── tree-sitter-loon/     # Tree-sitter grammar\n├── samples/              # Example programs\n└── tests/                # Test suite\n```\n\n## Development\n\n```bash\n# Run tests\ncargo test --workspace\n\n# Build WASM + dev server\ncd web \u0026\u0026 npm run dev\n\n# Build language server\ncargo build -p loon-lsp --release\n```\n\n## License\n\n[MIT](LICENSE)\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fecto%2Floon","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fecto%2Floon","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fecto%2Floon/lists"}