parsing-source

# Parsing source into a syntax tree `ts-pack parse <file>` parses one source file with the matching tree-sitter grammar and prints the resulting concrete syntax tree. Use it when the user wants the tree itself — to inspect node structure, debug a grammar, or feed an s-expression to another tool. ## Quick recipe ```bash # S-expression (default) — auto-detects language from the file extension ts-pack parse src/main.rs # JSON form: { "language", "sexp", "has_errors" } ts-pack parse src/main.rs --format json ``` ## Flag surface | Flag | Short | Default | Purpose | | ---- | ----- | ------- | ------- | | `--language <name>` | `-l` | auto | Override the language (skip extension detection). | | `--format <fmt>` | `-f` | `sexp` | `sexp` or `json`. | The parser library for the language downloads on first use and is cached. ## Language detection The language is auto-detected from the file extension. Override it when the extension is missing, misleading, or you are reading from stdin: ```bash # Misleading extension or no extension: ts-pack parse script --language bash # stdin (use "-" as the file): cat snippet.py | ts-pack parse - --language python ``` stdin cannot be auto-detected by path; always pass `--language` with `-`. For content-based detection without a path, use the SDK (`detect_language_from_content`) — see the `detecting-languages` skill. ## Output shapes ### S-expression A nested `(node_type child ...)` tree. Compact, good for eyeballing structure or piping to a grammar tool. ### JSON ```json { "language": "rust", "sexp": "(source_file (function_item ...))", "has_errors": false } ``` Read `has_errors` to know whether the parse produced any error nodes — a fast syntax check. For positioned, per-error detail use `ts-pack process <file> --diagnostics` (see `extracting-code-structure`). ## Examples ```bash # Inspect a TypeScript file's tree ts-pack parse src/app.ts # Machine-readable, then check for syntax errors with jq ts-pack parse src/app.ts --format json | jq '.has_errors' # Parse a heredoc as Python printf 'def f():\n return 1\n' | ts-pack parse - -l python ``` ## When to reach for process instead `parse` gives you the raw tree. If the user wants structured metadata (functions, imports, exports, symbols, docstrings) rather than the tree, use `ts-pack process` — see the `extracting-code-structure` skill.