TypeScript API Reference

TypeScript API Reference v1.8.0-rc.26¶

Functions¶

detectLanguageFromExtension()¶

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

Returns null for unrecognized extensions. The match is case-insensitive.

Signature:

function detectLanguageFromExtension(ext: string): string | null

Parameters:

Returns: string | null

detectLanguageFromPath()¶

Detect language name from a file path.

Extracts the file extension and looks it up. Returns null if the path has no extension or the extension is not recognized.

Signature:

function detectLanguageFromPath(path: string): string | null

Parameters:

Returns: string | null

detectLanguageFromContent()¶

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 null when content does not start with #!, the shebang is malformed, or the interpreter is not recognised.

Signature:

function detectLanguageFromContent(content: string): string | null

Parameters:

Returns: string | null

parseString()¶

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:

function parseString(language: string, source: Buffer): Tree

Parameters:

Returns: Tree

Errors: Throws Error with a descriptive message.

getHighlightsQuery()¶

Get the highlights query for a language, if bundled.

Returns the contents of highlights.scm as a static string, or null if no highlights query is bundled for this language.

Signature:

function getHighlightsQuery(language: string): string | null

Parameters:

Returns: string | null

getInjectionsQuery()¶

Get the injections query for a language, if bundled.

Returns the contents of injections.scm as a static string, or null if no injections query is bundled for this language.

Signature:

function getInjectionsQuery(language: string): string | null

Parameters:

Returns: string | null

getLocalsQuery()¶

Get the locals query for a language, if bundled.

Returns the contents of locals.scm as a static string, or null if no locals query is bundled for this language.

Signature:

function getLocalsQuery(language: string): string | null

Parameters:

Returns: string | null

getLanguage()¶

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:

function getLanguage(name: string): Language

Parameters:

Returns: Language

Errors: Throws Error with a descriptive message.

getParser()¶

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:

function getParser(name: string): Parser

Parameters:

Returns: Parser

Errors: Throws Error with a descriptive message.

detectLanguage()¶

Detect language name from a file path or extension.

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

Signature:

function detectLanguage(path: string): string | null

Parameters:

Returns: string | null

availableLanguages()¶

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

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

Signature:

function availableLanguages(): Array<string>

Returns: Array<string>

hasLanguage()¶

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:

function hasLanguage(name: string): boolean

Parameters:

Returns: boolean

languageCount()¶

Return the number of available languages.

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

Signature:

function languageCount(): number

Returns: number

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:

function process(source: string, config: ProcessConfig): ProcessResult

Parameters:

Returns: ProcessResult

Errors: Throws Error with a descriptive message.

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:

function init(config: PackConfig): void

Parameters:

Returns: void

Errors: Throws Error with a descriptive message.

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:

function configure(config: PackConfig): void

Parameters:

Returns: void

Errors: Throws Error with a descriptive message.

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:

function download(names: Array<string>): number

Parameters:

Returns: number

Errors: Throws Error with a descriptive message.

downloadAll()¶

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:

function downloadAll(): number

Returns: number

Errors: Throws Error with a descriptive message.

manifestLanguages()¶

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:

function manifestLanguages(): Array<string>

Returns: Array<string>

Errors: Throws Error with a descriptive message.

downloadedLanguages()¶

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:

function downloadedLanguages(): Array<string>

Returns: Array<string>

cleanCache()¶

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:

function cleanCache(): void

Returns: void

Errors: Throws Error with a descriptive message.

cacheDir()¶

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:

function cacheDir(): string

Returns: string

Errors: Throws Error with a descriptive message.

Types¶

ChunkContext¶

Metadata for a single chunk of source code.

CodeChunk¶

A chunk of source code with rich metadata.

CommentInfo¶

A comment extracted from source code.

Diagnostic¶

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

DocSection¶

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

DocstringInfo¶

A docstring extracted from source code.

DownloadManager¶

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

Methods¶

new()¶

Create a new download manager for the given version.

Signature:

static new(version: string): DownloadManager

withCacheDir()¶

Create a download manager with a custom cache directory.

Signature:

static withCacheDir(version: string, cacheDir: string): DownloadManager

defaultCacheDir()¶

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

Signature:

static defaultCacheDir(version: string): string

cacheDir()¶

Return the path to the libs cache directory.

Signature:

cacheDir(): string

installedLanguages()¶

List languages that are already downloaded and cached.

Signature:

installedLanguages(): Array<string>

ensureLanguages()¶

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

Signature:

ensureLanguages(names: Array<string>): void

ensureGroup()¶

Ensure all languages in a named group are available.

Signature:

ensureGroup(group: string): void

libPath()¶

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

Signature:

libPath(name: string): string

fetchManifest()¶

Fetch the parser manifest from GitHub Releases.

Signature:

fetchManifest(): ParserManifest

cleanCache()¶

Remove all cached parser libraries.

Signature:

cleanCache(): void

ExportInfo¶

An export statement extracted from source code.

FileMetrics¶

Aggregate metrics for a source file.

ImportInfo¶

An import statement extracted from source code.

Language¶

LanguageInfo¶

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¶

withLibsDir()¶

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:

static withLibsDir(libsDir: string): LanguageRegistry

addExtraLibsDir()¶

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:

addExtraLibsDir(dir: string): void

getLanguage()¶

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:

getLanguage(name: string): Language

availableLanguages()¶

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:

availableLanguages(): Array<string>

hasLanguage()¶

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:

hasLanguage(name: string): boolean

languageCount()¶

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

Signature:

languageCount(): number

process()¶

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

Signature:

process(source: string, config: ProcessConfig): ProcessResult

default()¶

Signature:

static 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.

Methods¶

fromTomlFile()¶

Load configuration from a TOML file.

Errors:

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

Signature:

static fromTomlFile(path: string): PackConfig

discover()¶

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

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

Returns null if no configuration file is found.

Signature:

static discover(): PackConfig | null

Parser¶

ParserManifest¶

Manifest describing available parser downloads for a specific version.

PlatformBundle¶

ProcessConfig¶

Configuration for the process() function.

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

Methods¶

default()¶

Signature:

static default(): ProcessConfig

withChunking()¶

Enable chunking with the given maximum chunk size in bytes.

Signature:

withChunking(maxSize: number): ProcessConfig

all()¶

Enable all analysis features.

Signature:

all(): ProcessConfig

minimal()¶

Disable all analysis features (only metrics computed).

Signature:

minimal(): 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.

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).

StructureItem¶

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

SymbolInfo¶

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

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.

CommentKind¶

The kind of a comment found in source code.

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

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).

ExportKind¶

The kind of an export statement found in source code.

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

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.

DiagnosticSeverity¶

Severity level of a diagnostic produced during parsing.

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

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.

Errors are thrown as plain Error objects with descriptive messages.