Rust API Reference

Rust API Reference v1.8.0-rc.26¶

Functions¶

detect_language_from_extension()¶

Detect language name from a file extension (without leading dot).

Returns None for unrecognized extensions. The match is case-insensitive.

Signature:

pub fn detect_language_from_extension(ext: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`ext`	`String`	Yes	The ext

Returns: Option<String>

detect_language_from_path()¶

Detect language name from a file path.

Extracts the file extension and looks it up. Returns None if the path has no extension or the extension is not recognized.

Signature:

pub fn detect_language_from_path(path: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`path`	`String`	Yes	Path to the file

Returns: Option<String>

detect_language_from_content()¶

Detect language name from file content using the shebang line (#!).

Inspects only the first line of content. If it begins with #!, the interpreter name is extracted and mapped to a language name.

Handles common patterns:

#!/usr/bin/env python3 → "python"
#!/bin/bash → "bash"
#!/usr/bin/env node → "javascript"

The -S flag accepted by some env implementations is skipped automatically. Version suffixes (e.g. python3.11, ruby3.2) are stripped before matching.

Returns None when content does not start with #!, the shebang is malformed, or the interpreter is not recognised.

Signature:

pub fn detect_language_from_content(content: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`content`	`String`	Yes	The content to process

Returns: Option<String>

parse_string()¶

Parse source code with the named language, returning the syntax tree.

Uses the global registry to look up the language by name. Caches parsers per-thread so repeated calls for the same language avoid re-creating the parser.

Signature:

pub fn parse_string(language: &str, source: &[u8]) -> Result<Tree, Error>

Parameters:

Name	Type	Required	Description
`language`	`String`	Yes	The language
`source`	`Vec<u8>`	Yes	The source

Returns: Tree

Errors: Returns Err(Error).

get_highlights_query()¶

Get the highlights query for a language, if bundled.

Returns the contents of highlights.scm as a static string, or None if no highlights query is bundled for this language.

Signature:

pub fn get_highlights_query(language: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`language`	`String`	Yes	The language

Returns: Option<String>

get_injections_query()¶

Get the injections query for a language, if bundled.

Returns the contents of injections.scm as a static string, or None if no injections query is bundled for this language.

Signature:

pub fn get_injections_query(language: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`language`	`String`	Yes	The language

Returns: Option<String>

get_locals_query()¶

Get the locals query for a language, if bundled.

Returns the contents of locals.scm as a static string, or None if no locals query is bundled for this language.

Signature:

pub fn get_locals_query(language: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`language`	`String`	Yes	The language

Returns: Option<String>

get_language()¶

Get a tree-sitter Language by name using the global registry.

Resolves language aliases (e.g., "shell" maps to "bash"). When the download feature is enabled (default), automatically downloads the parser from GitHub releases if not found locally.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.Download if auto-download fails.

Signature:

pub fn get_language(name: &str) -> Result<Language, Error>

Parameters:

Name	Type	Required	Description
`name`	`String`	Yes	The name

Returns: Language

Errors: Returns Err(Error).

get_parser()¶

Get a tree-sitter Parser pre-configured for the given language.

This is a convenience function that calls get_language and configures a new parser in one step.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.ParserSetup if the language cannot be applied to the parser.

Signature:

pub fn get_parser(name: &str) -> Result<Parser, Error>

Parameters:

Name	Type	Required	Description
`name`	`String`	Yes	The name

Returns: Parser

Errors: Returns Err(Error).

detect_language()¶

Detect language name from a file path or extension.

This compatibility alias matches the pre-Alef Python binding API.

Signature:

pub fn detect_language(path: &str) -> Option<String>

Parameters:

Name	Type	Required	Description
`path`	`String`	Yes	Path to the file

Returns: Option<String>

available_languages()¶

List all available language names (sorted, deduplicated, includes aliases).

Returns names of both statically compiled and dynamically loadable languages, plus any configured aliases.

Signature:

pub fn available_languages() -> Vec<String>

Returns: Vec<String>

has_language()¶

Check if a language is available by name or alias.

Returns true if the language can be loaded (statically compiled, dynamically available, or a known alias for one of these).

Signature:

pub fn has_language(name: &str) -> bool

Parameters:

Name	Type	Required	Description
`name`	`String`	Yes	The name

Returns: bool

language_count()¶

Return the number of available languages.

Includes statically compiled languages, dynamically loadable languages, and aliases.

Signature:

pub fn language_count() -> usize

Returns: usize

process()¶

Process source code and extract file intelligence using the global registry.

Parses the source with tree-sitter and extracts metrics, structure, imports, exports, comments, docstrings, symbols, diagnostics, and/or chunks based on the flags set in ProcessConfig.

Errors:

Returns an error if the language is not found or parsing fails.

Signature:

pub fn process(source: &str, config: ProcessConfig) -> Result<ProcessResult, Error>

Parameters:

Name	Type	Required	Description
`source`	`String`	Yes	The source
`config`	`ProcessConfig`	Yes	The configuration options

Returns: ProcessResult

Errors: Returns Err(Error).

init()¶

Initialize the language pack with the given configuration.

Applies any custom cache directory, then downloads all languages and groups specified in the config. This is the recommended entry point when you want to pre-warm the cache before use.

Errors:

Returns an error if configuration cannot be applied or if downloads fail.

Signature:

pub fn init(config: PackConfig) -> Result<(), Error>

Parameters:

Name	Type	Required	Description
`config`	`PackConfig`	Yes	The configuration options

Returns: ()

Errors: Returns Err(Error).

configure()¶

Apply download configuration without downloading anything.

Use this to set a custom cache directory before the first call to get_language or any download function. Changing the cache dir after languages have been registered has no effect on already-loaded languages.

Errors:

Returns an error if the lock cannot be acquired.

Signature:

pub fn configure(config: PackConfig) -> Result<(), Error>

Parameters:

Name	Type	Required	Description
`config`	`PackConfig`	Yes	The configuration options

Returns: ()

Errors: Returns Err(Error).

download()¶

Download specific languages to the local cache.

Returns the number of newly downloaded languages (languages that were already cached are not counted).

Errors:

Returns an error if any language is not available in the manifest or if the download fails.

Signature:

pub fn download(names: Vec<String>) -> Result<usize, Error>

Parameters:

Name	Type	Required	Description
`names`	`Vec<String>`	Yes	The names

Returns: usize

Errors: Returns Err(Error).

download_all()¶

Download all available languages from the remote manifest.

Returns the number of newly downloaded languages.

Errors:

Returns an error if the manifest cannot be fetched or a download fails.

Signature:

pub fn download_all() -> Result<usize, Error>

Returns: usize

Errors: Returns Err(Error).

manifest_languages()¶

Return all language names available in the remote manifest (305).

Fetches (and caches) the remote manifest to discover the full list of downloadable languages. Use downloaded_languages to list what is already cached locally.

Errors:

Returns an error if the manifest cannot be fetched.

Signature:

pub fn manifest_languages() -> Result<Vec<String>, Error>

Returns: Vec<String>

Errors: Returns Err(Error).

downloaded_languages()¶

Return languages that are already downloaded and cached locally.

Does not perform any network requests. Returns an empty list if the cache directory does not exist or cannot be read.

Signature:

pub fn downloaded_languages() -> Vec<String>

Returns: Vec<String>

clean_cache()¶

Delete all cached parser shared libraries.

Resets the cache registration so the next call to get_language or a download function will re-register the (now empty) cache directory.

Errors:

Returns an error if the cache directory cannot be removed.

Signature:

pub fn clean_cache() -> Result<(), Error>

Returns: ()

Errors: Returns Err(Error).

cache_dir()¶

Return the effective cache directory path.

This is either the custom path set via configure / init or the default: ~/.cache/tree-sitter-language-pack/v{version}/libs/.

Errors:

Returns an error if the system cache directory cannot be determined.

Signature:

pub fn cache_dir() -> Result<PathBuf, Error>

Returns: PathBuf

Errors: Returns Err(Error).

Types¶

ChunkContext¶

Metadata for a single chunk of source code.

Field	Type	Default	Description
`language`	`String`	—	Language
`chunk_index`	`usize`	—	Chunk index
`total_chunks`	`usize`	—	Total chunks
`node_types`	`Vec<String>`	`vec![]`	Node types
`context_path`	`Vec<String>`	`vec![]`	Context path
`symbols_defined`	`Vec<String>`	`vec![]`	Symbols defined
`comments`	`Vec<CommentInfo>`	`vec![]`	Comments
`docstrings`	`Vec<DocstringInfo>`	`vec![]`	Docstrings
`has_error_nodes`	`bool`	—	Whether error nodes

CodeChunk¶

A chunk of source code with rich metadata.

Field	Type	Default	Description
`content`	`String`	—	The extracted text content
`start_byte`	`usize`	—	Start byte
`end_byte`	`usize`	—	End byte
`start_line`	`usize`	—	Start line
`end_line`	`usize`	—	End line
`metadata`	`ChunkContext`	—	Document metadata

CommentInfo¶

A comment extracted from source code.

Field	Type	Default	Description
`text`	`String`	—	Text
`kind`	`CommentKind`	`CommentKind::Line`	Kind (comment kind)
`span`	`Span`	—	Span (span)
`associated_node`	`Option<String>`	`Default::default()`	Associated node

Diagnostic¶

A diagnostic (syntax error, missing node, etc.) from parsing.

Field	Type	Default	Description
`message`	`String`	—	Message
`severity`	`DiagnosticSeverity`	`DiagnosticSeverity::Error`	Severity (diagnostic severity)
`span`	`Span`	—	Span (span)

DocSection¶

A section within a docstring (e.g., Args, Returns, Raises).

Field	Type	Default	Description
`kind`	`String`	—	Kind
`name`	`Option<String>`	`Default::default()`	The name
`description`	`String`	—	Human-readable description

DocstringInfo¶

A docstring extracted from source code.

Field	Type	Default	Description
`text`	`String`	—	Text
`format`	`DocstringFormat`	`DocstringFormat::PythonTripleQuote`	Format (docstring format)
`span`	`Span`	—	Span (span)
`associated_item`	`Option<String>`	`Default::default()`	Associated item
`parsed_sections`	`Vec<DocSection>`	`vec![]`	Parsed sections

DownloadManager¶

Manages downloading and caching of pre-built parser shared libraries.

Methods¶

new()¶

Create a new download manager for the given version.

Signature:

pub fn new(version: &str) -> DownloadManager

with_cache_dir()¶

Create a download manager with a custom cache directory.

Signature:

pub fn with_cache_dir(version: &str, cache_dir: PathBuf) -> DownloadManager

default_cache_dir()¶

Default cache directory: ~/.cache/tree-sitter-language-pack/v{version}/libs/

Signature:

pub fn default_cache_dir(version: &str) -> PathBuf

cache_dir()¶

Return the path to the libs cache directory.

Signature:

pub fn cache_dir(&self) -> PathBuf

installed_languages()¶

List languages that are already downloaded and cached.

Signature:

pub fn installed_languages(&self) -> Vec<String>

ensure_languages()¶

Ensure the specified languages are available in the cache. Downloads the platform bundle if any requested languages are missing.

Signature:

pub fn ensure_languages(&self, names: Vec<String>)

ensure_group()¶

Ensure all languages in a named group are available.

Signature:

pub fn ensure_group(&self, group: &str)

lib_path()¶

Get the expected path for a language's shared library in the cache.

Signature:

pub fn lib_path(&self, name: &str) -> PathBuf

fetch_manifest()¶

Fetch the parser manifest from GitHub Releases.

Signature:

pub fn fetch_manifest(&self) -> ParserManifest

clean_cache()¶

Remove all cached parser libraries.

Signature:

pub fn clean_cache(&self)

ExportInfo¶

An export statement extracted from source code.

Field	Type	Default	Description
`name`	`String`	—	The name
`kind`	`ExportKind`	`ExportKind::Named`	Kind (export kind)
`span`	`Span`	—	Span (span)

FileMetrics¶

Aggregate metrics for a source file.

Field	Type	Default	Description
`total_lines`	`usize`	—	Total lines
`code_lines`	`usize`	—	Code lines
`comment_lines`	`usize`	—	Comment lines
`blank_lines`	`usize`	—	Blank lines
`total_bytes`	`usize`	—	Total bytes
`node_count`	`usize`	—	Number of nodes
`error_count`	`usize`	—	Number of errors
`max_depth`	`usize`	—	Maximum depth

ImportInfo¶

An import statement extracted from source code.

Field	Type	Default	Description
`source`	`String`	—	Source
`items`	`Vec<String>`	`vec![]`	Items
`alias`	`Option<String>`	`Default::default()`	Alias
`is_wildcard`	`bool`	—	Whether wildcard
`span`	`Span`	—	Span (span)

Language¶

LanguageInfo¶

Field	Type	Default	Description
`group`	`String`	—	Group
`size`	`u64`	—	Size in bytes

LanguageRegistry¶

Thread-safe registry of tree-sitter language parsers.

Manages both statically compiled and dynamically loaded language grammars. Use LanguageRegistry.new() for the default registry, or access the global instance via the module-level convenience functions (crate.get_language, crate.available_languages, etc.).

Methods¶

with_libs_dir()¶

Create a registry with a custom directory for dynamic libraries.

Overrides the default build-time library directory. Useful when dynamic grammar shared libraries are stored in a non-standard location.

Signature:

pub fn with_libs_dir(libs_dir: PathBuf) -> LanguageRegistry

add_extra_libs_dir()¶

Add an additional directory to search for dynamic libraries.

When get_language cannot find a grammar in the primary library directory, it searches these extra directories in order. Typically used by the download system to register its cache directory.

Takes &self (not &mut self) because extra_lib_dirs uses interior mutability via an Arc<RwLock<...>>, so the outer registry can remain immutable while the directory list is updated.

Signature:

pub fn add_extra_libs_dir(&self, dir: PathBuf)

get_language()¶

Get a tree-sitter Language by name.

Resolves aliases (e.g., "shell" -> "bash", "makefile" -> "make"), then looks up the language in the static table. When the dynamic-loading feature is enabled, falls back to loading a shared library on demand.

Errors:

Returns Error.LanguageNotFound if the name (after alias resolution) does not match any known grammar.

Signature:

pub fn get_language(&self, name: &str) -> Language

available_languages()¶

List all available language names, sorted and deduplicated.

Includes statically compiled languages, dynamically loadable languages (if the dynamic-loading feature is enabled), and all configured aliases.

Signature:

pub fn available_languages(&self) -> Vec<String>

has_language()¶

Check whether a language is available by name or alias.

Returns true if the language can be loaded, either from the static table or from a dynamic library on disk.

Signature:

pub fn has_language(&self, name: &str) -> bool

language_count()¶

Return the total number of available languages (including aliases).

Signature:

pub fn language_count(&self) -> usize

process()¶

Parse source code and extract file intelligence based on config in a single pass.

Signature:

pub fn process(&self, source: &str, config: ProcessConfig) -> ProcessResult

default()¶

Signature:

pub fn default() -> LanguageRegistry

PackConfig¶

Configuration for the tree-sitter language pack.

Controls cache directory and which languages to pre-download. Can be loaded from a TOML file, constructed programmatically, or passed as a dict/object from language bindings.

Field	Type	Default	Description
`cache_dir`	`Option<PathBuf>`	`Default::default()`	Override default cache directory. Default: `~/.cache/tree-sitter-language-pack/v{version}/libs/`
`languages`	`Option<Vec<String>>`	`vec![]`	Languages to pre-download on init. Each entry is a language name (e.g. `"python"`, `"rust"`).
`groups`	`Option<Vec<String>>`	`vec![]`	Language groups to pre-download (e.g. `"web"`, `"systems"`, `"scripting"`).

Methods¶

from_toml_file()¶

Load configuration from a TOML file.

Errors:

Returns an error if the file cannot be read or the TOML is invalid.

Signature:

pub fn from_toml_file(path: PathBuf) -> PackConfig

discover()¶

Discover configuration by searching for language-pack.toml in:

Current directory and up to 10 parent directories
$XDG_CONFIG_HOME/tree-sitter-language-pack/config.toml
~/.config/tree-sitter-language-pack/config.toml

Returns None if no configuration file is found.

Signature:

pub fn discover() -> Option<PackConfig>

Parser¶

ParserManifest¶

Manifest describing available parser downloads for a specific version.

Field	Type	Default	Description
`version`	`String`	—	Version string
`platforms`	`HashMap<String, PlatformBundle>`	—	Platforms
`languages`	`HashMap<String, LanguageInfo>`	—	Languages
`groups`	`HashMap<String, Vec<String>>`	—	Groups

PlatformBundle¶

Field	Type	Default	Description
`url`	`String`	—	Url
`sha256`	`String`	—	Sha256
`size`	`u64`	—	Size in bytes

ProcessConfig¶

Configuration for the process() function.

Controls which analysis features are enabled and whether chunking is performed.

Field	Type	Default	Description
`language`	`String`	—	Language name (required).
`structure`	`bool`	`true`	Extract structural items (functions, classes, etc.). Default: true.
`imports`	`bool`	`true`	Extract import statements. Default: true.
`exports`	`bool`	`true`	Extract export statements. Default: true.
`comments`	`bool`	`false`	Extract comments. Default: false.
`docstrings`	`bool`	`false`	Extract docstrings. Default: false.
`symbols`	`bool`	`false`	Extract symbol definitions. Default: false.
`diagnostics`	`bool`	`false`	Include parse diagnostics. Default: false.
`chunk_max_size`	`Option<usize>`	`None`	Maximum chunk size in bytes. `None` disables chunking.

Methods¶

default()¶

Signature:

pub fn default() -> ProcessConfig

with_chunking()¶

Enable chunking with the given maximum chunk size in bytes.

Signature:

pub fn with_chunking(&self, max_size: usize) -> ProcessConfig

all()¶

Enable all analysis features.

Signature:

pub fn all(&self) -> ProcessConfig

minimal()¶

Disable all analysis features (only metrics computed).

Signature:

pub fn minimal(&self) -> ProcessConfig

ProcessResult¶

Complete analysis result from processing a source file.

Contains metrics, structural analysis, imports/exports, comments, docstrings, symbols, diagnostics, and optionally chunked code segments. Fields are populated based on the crate.ProcessConfig flags.

Field	Type	Default	Description
`language`	`String`	—	Language
`metrics`	`FileMetrics`	—	Metrics (file metrics)
`structure`	`Vec<StructureItem>`	`vec![]`	Structure
`imports`	`Vec<ImportInfo>`	`vec![]`	Imports
`exports`	`Vec<ExportInfo>`	`vec![]`	Exports
`comments`	`Vec<CommentInfo>`	`vec![]`	Comments
`docstrings`	`Vec<DocstringInfo>`	`vec![]`	Docstrings
`symbols`	`Vec<SymbolInfo>`	`vec![]`	Symbols
`diagnostics`	`Vec<Diagnostic>`	`vec![]`	Diagnostics
`chunks`	`Vec<CodeChunk>`	`vec![]`	Text chunks for chunking/embedding

Span¶

Byte and line/column range in source code.

Represents both byte offsets (for slicing) and human-readable line/column positions (for display and diagnostics).

Field	Type	Default	Description
`start_byte`	`usize`	—	Start byte
`end_byte`	`usize`	—	End byte
`start_line`	`usize`	—	Start line
`start_column`	`usize`	—	Start column
`end_line`	`usize`	—	End line
`end_column`	`usize`	—	End column

StructureItem¶

A structural item (function, class, struct, etc.) in source code.

Field	Type	Default	Description
`kind`	`StructureKind`	`StructureKind::Function`	Kind (structure kind)
`name`	`Option<String>`	`Default::default()`	The name
`visibility`	`Option<String>`	`Default::default()`	Visibility
`span`	`Span`	—	Span (span)
`children`	`Vec<StructureItem>`	`vec![]`	Children
`decorators`	`Vec<String>`	`vec![]`	Decorators
`doc_comment`	`Option<String>`	`Default::default()`	Doc comment
`signature`	`Option<String>`	`Default::default()`	Signature
`body_span`	`Option<Span>`	`Default::default()`	Body span (span)

SymbolInfo¶

A symbol (variable, function, type, etc.) extracted from source code.

Field	Type	Default	Description
`name`	`String`	—	The name
`kind`	`SymbolKind`	`SymbolKind::Variable`	Kind (symbol kind)
`span`	`Span`	—	Span (span)
`type_annotation`	`Option<String>`	`Default::default()`	Type annotation
`doc`	`Option<String>`	`Default::default()`	Doc

Tree¶

Enums¶

StructureKind¶

The kind of structural item found in source code.

Categorizes top-level and nested declarations such as functions, classes, structs, enums, traits, and more. Use Other for language-specific constructs that do not fit a standard category.

Value	Description
`Function`	Function
`Method`	Method
`Class`	Class
`Struct`	Struct
`Interface`	Interface
`Enum`	Enum
`Module`	Module
`Trait`	Trait
`Impl`	Impl
`Namespace`	Namespace
`Other`	Other — Fields: `0`: `String`

CommentKind¶

The kind of a comment found in source code.

Distinguishes between single-line comments, block (multi-line) comments, and documentation comments.

Value	Description
`Line`	Line
`Block`	Block
`Doc`	Doc

DocstringFormat¶

The format of a docstring extracted from source code.

Identifies the docstring convention used, which varies by language (e.g., Python triple-quoted strings, JSDoc, Rustdoc /// comments).

Value	Description
`PythonTripleQuote`	Python triple quote
`JsDoc`	J s doc
`Rustdoc`	Rustdoc
`GoDoc`	Go doc
`JavaDoc`	Java doc
`Other`	Other — Fields: `0`: `String`

ExportKind¶

The kind of an export statement found in source code.

Covers named exports, default exports, and re-exports from other modules.

Value	Description
`Named`	Named
`Default`	Default
`ReExport`	Re export

SymbolKind¶

The kind of a symbol definition found in source code.

Categorizes symbol definitions such as variables, constants, functions, classes, types, interfaces, enums, and modules.

Value	Description
`Variable`	Variable
`Constant`	Constant
`Function`	Function
`Class`	Class
`Type`	Type
`Interface`	Interface
`Enum`	Enum
`Module`	Module
`Other`	Other — Fields: `0`: `String`

DiagnosticSeverity¶

Severity level of a diagnostic produced during parsing.

Used to classify parse errors, warnings, and informational messages found in the syntax tree.

Value	Description
`Error`	Error
`Warning`	Warning
`Info`	Info

Errors¶

Error¶

Errors that can occur when using the tree-sitter language pack.

Covers language lookup failures, parse errors, query errors, and I/O issues. Feature-gated variants are included when config, download, or related features are enabled.

Variant	Description
`LanguageNotFound`	Language '{0}' not found
`DynamicLoad`	Dynamic library load error:
`NullLanguagePointer`	Language function returned null pointer for '{0}'
`ParserSetup`	Failed to set parser language:
`LockPoisoned`	Registry lock poisoned:
`Config`	Configuration error:
`ParseFailed`	Parse failed: parsing returned no tree
`QueryError`	Query error:
`InvalidRange`	Invalid byte range:
`Io`	IO error: