# Tree-sitter — Incremental Parser Generator for Editors

> Tree-sitter is a general parser generator + incremental parsing library that powers fast, robust syntax highlighting, code folding, and structural edits in editors like Neovim, Zed, Helix, and GitHub.

## Install

Save in your project root:

# Tree-sitter — Incremental Parser Generator for Editors

## Quick Use
```bash
# Install the CLI
cargo install --locked tree-sitter-cli
# or: npm install -g tree-sitter-cli

# Scaffold and build a grammar
tree-sitter init-config
tree-sitter generate        # produces src/parser.c from grammar.js
tree-sitter parse example.c # shows the concrete syntax tree
tree-sitter playground       # browser playground for queries
```

## Introduction
Tree-sitter generates fast, incremental parsers and a small C runtime you can embed in editors. Given a declarative `grammar.js`, it produces an LR(1) + GLR parser that re-parses only the changed ranges on every keystroke — the key trick that makes language-aware editing feel instant. It powers syntax highlighting and structural navigation in Neovim, Zed, Helix, Atom (where it was born), GitHub code view, and Sourcegraph. Over 24,000 GitHub stars.

## What Tree-sitter Does
- Generates a parser in C from a JavaScript grammar definition — deterministic and reproducible.
- Parses source incrementally: a tiny edit triggers re-parsing of just the affected subtree.
- Ships a query language (S-expressions) for extracting highlights, locals, folds, and text objects.
- Handles error recovery gracefully so you always get a (partial) tree, even for syntactically broken code.
- Runs the same parser in editors (C runtime), browsers (WASM build), and CLIs.

## Architecture Overview
Tree-sitter compiles an LR(1) table with GLR fallback for ambiguous productions, emitted as a single C file. At runtime the parser walks the input, producing a compact concrete syntax tree (CST) stored as packed node structs. On edit, an edit range tells the parser which nodes can be reused; it stitches the old tree with a fresh parse of the dirty range. Queries are compiled to bytecode and matched against subtrees to produce highlight captures or structural edits. There are over 200 community grammars — C, Rust, Go, Python, TypeScript, HTML, Bash, TOML, and more.

## Self-Hosting & Configuration
- Use the Rust/Node CLI to author grammars — `tree-sitter generate` is the only required command.
- Embed the generated C parser in your editor or tool with the ~100 KB runtime (C or WASM).
- Keep highlight queries in `queries/highlights.scm` — most editors load them automatically.
- Use `tree-sitter test` with corpus fixtures to verify grammar changes don't regress.
- Publish grammars to npm or crates as prebuilt binaries for fast installs.

## Key Features
- Truly incremental parsing — sub-millisecond re-parse on keystrokes.
- Rich query language for highlights, folds, indents, and textobjects.
- Error-resilient trees for editor workflows where code is constantly incomplete.
- C, Rust, Python, Go, Node, Swift, and WASM bindings.
- Massive grammar ecosystem maintained by language communities.

## Comparison with Similar Tools
- **Pygments/TextMate grammars** — regex-based tokenizers; fast but fragile, no real AST.
- **LSP servers (rust-analyzer, etc.)** — give semantic info, but heavier and language-specific; tree-sitter complements them.
- **ANTLR** — powerful parser generator, better for compilers; no incremental parsing story.
- **Lezer (CodeMirror 6)** — similar incremental parser in TypeScript; tighter CodeMirror integration.
- **Lark/Parsec** — general parsers for tooling; neither targets editor latency.

## FAQ
**Q:** Do I need to write a grammar to use tree-sitter?
A: No — if a grammar already exists for your language, just install it. Writing grammars is for when you need new language support.

**Q:** Can tree-sitter replace an LSP?
A: It replaces the lexer and parser pieces but not semantic analysis. Most editors run both side by side.

**Q:** How big is the runtime?
A: Around 100 KB of C; each grammar adds 100-500 KB depending on complexity.

**Q:** Is it usable in the browser?
A: Yes — `tree-sitter.wasm` runs in all modern browsers and Node.

## Sources
- https://github.com/tree-sitter/tree-sitter
- https://tree-sitter.github.io/tree-sitter/

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Source: https://tokrepo.com/en/workflows/ffd869e7-3907-11f1-9bc6-00163e2b0d79
Author: AI Open Source