Go API Reference

Go API Reference v1.12.5

Functions

DetectLanguageFromExtension()

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

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

Signature:

func DetectLanguageFromExtension(ext string) *string

Example:

result := DetectLanguageFromExtension("value")

Parameters:

Name	Type	Required	Description
`Ext`	`string`	Yes	The ext

Returns: *string

DetectLanguageFromPath()

Detect language name from a file path.

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

Signature:

func DetectLanguageFromPath(path string) *string

Example:

result := DetectLanguageFromPath("value")

Parameters:

Name	Type	Required	Description
`Path`	`string`	Yes	Path to the file

Returns: *string

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

Signature:

func DetectLanguageFromContent(content string) *string

Example:

result := DetectLanguageFromContent("value")

Parameters:

Name	Type	Required	Description
`Content`	`string`	Yes	The content to process

Returns: *string

GetHighlightsQuery()

Get the highlights query for a language, if bundled.

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

Signature:

func GetHighlightsQuery(language string) *string

Example:

result := GetHighlightsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

GetInjectionsQuery()

Get the injections query for a language, if bundled.

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

Signature:

func GetInjectionsQuery(language string) *string

Example:

result := GetInjectionsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

GetLocalsQuery()

Get the locals query for a language, if bundled.

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

Signature:

func GetLocalsQuery(language string) *string

Example:

result := GetLocalsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

GetTagsQuery()

Get the tags query for a language, if bundled.

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

Signature:

func GetTagsQuery(language string) *string

Example:

result := GetTagsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

GetIndentsQuery()

Get the indents query for a language, if bundled.

Returns the contents of indents.scm (used for auto-indentation) as a static string, or nil if no indents query is bundled for this language.

Signature:

func GetIndentsQuery(language string) *string

Example:

result := GetIndentsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

GetFoldsQuery()

Get the folds query for a language, if bundled.

Returns the contents of folds.scm (used for code folding) as a static string, or nil if no folds query is bundled for this language.

Signature:

func GetFoldsQuery(language string) *string

Example:

result := GetFoldsQuery("value")

Parameters:

Name	Type	Required	Description
`Language`	`string`	Yes	The language

Returns: *string

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:

func GetLanguage(name string) (Language, error)

Example:

result, err := GetLanguage("value")
if err != nil {
    return err
}

Parameters:

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

Returns: Language

Errors: Returns error.

GetParser()

Get a 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:

func GetParser(name string) (Parser, error)

Example:

result, err := GetParser("value")
if err != nil {
    return err
}

Parameters:

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

Returns: Parser

Errors: Returns error.

DetectLanguage()

Detect language name from a file path or extension.

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

Signature:

func DetectLanguage(path string) *string

Example:

result := DetectLanguage("value")

Parameters:

Name	Type	Required	Description
`Path`	`string`	Yes	Path to the file

Returns: *string

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:

func AvailableLanguages() []string

Example:

result := AvailableLanguages()

Returns: []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:

func HasLanguage(name string) bool

Example:

result := HasLanguage("value")

Parameters:

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

Returns: bool

LanguageCount()

Return the number of available languages.

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

Signature:

func LanguageCount() int

Example:

result := LanguageCount()

Returns: int

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:

func Process(source string, config ProcessConfig) (ProcessResult, error)

Example:

result, err := Process("value", ProcessConfig{})
if err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Source`	`string`	Yes	The source
`Config`	`ProcessConfig`	Yes	The configuration options

Returns: ProcessResult

Errors: Returns 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:

func Init(config PackConfig) error

Example:

if err := Init(PackConfig{}); err != nil {
    return err
}

Parameters:

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

Returns: No return value.

Errors: Returns 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:

func Configure(config PackConfig) error

Example:

if err := Configure(PackConfig{}); err != nil {
    return err
}

Parameters:

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

Returns: No return value.

Errors: Returns error.

Download()

Download specific languages to the local cache.

Returns the number of requested languages available after the call. Already compiled or cached languages are included in the count.

Errors:

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

Signature:

func Download(names []string) (int, error)

Example:

result, err := Download(nil)
if err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Names`	`\[\]string`	Yes	The names

Returns: int

Errors: Returns error.

Prefetch()

Prefetch grammars: download any not already loadable from disk, then load every requested language into the process registry so a subsequent hot loop only parses.

Unlike download(), this does not trust in-memory availability — it downloads whenever a grammar is not actually loadable from disk (fixing the case where a known-but-not-downloaded grammar is reported present), then resolves and caches every requested language. Call it once, up front, before a parallel workload.

Errors:

Returns Error.Download if a required grammar cannot be fetched, or Error.LanguageNotFound if a requested name is unknown.

Signature:

func Prefetch(languages []string) error

Example:

if err := Prefetch(nil); err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Languages`	`\[\]string`	Yes	The languages

Returns: No return value.

Errors: Returns error.

Prefetch()

Prefetch grammars by loading each into the registry.

Without the download feature there is no network step — every requested language must already be statically compiled or present on disk.

Errors:

Returns Error.LanguageNotFound if a requested language is not available.

Signature:

func Prefetch(languages []string) error

Example:

if err := Prefetch(nil); err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Languages`	`\[\]string`	Yes	The languages

Returns: No return value.

Errors: Returns error.

DownloadAll()

Download all available languages from the remote manifest.

Downloads the platform bundle and extracts every library it contains. Languages that appear in the manifest but are absent from the bundle (e.g. grammars that failed to compile at release time) are silently skipped — they are not treated as an error.

Returns the total number of languages now available (statically compiled plus downloaded and cached).

Errors:

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

Signature:

func DownloadAll() (int, error)

Example:

result, err := DownloadAll()
if err != nil {
    return err
}

Returns: int

Errors: Returns error.

DownloadGroup()

Download every language in a named group (e.g. "web", "data").

Groups are defined in the remote manifest and let you ensure a curated set of related grammars in one call instead of listing each name to download(). Already-cached languages are skipped.

Returns the total number of languages now available (statically compiled plus downloaded and cached).

Errors:

Returns an error if the manifest cannot be fetched, the group is unknown, or any constituent language fails to download.

Signature:

func DownloadGroup(name string) (int, error)

Example:

result, err := DownloadGroup("value")
if err != nil {
    return err
}

Parameters:

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

Returns: int

Errors: Returns error.

ManifestLanguages()

Return all language names available in the remote manifest (306).

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:

func ManifestLanguages() ([]string, error)

Example:

result, err := ManifestLanguages()
if err != nil {
    return err
}

Returns: []string

Errors: Returns error.

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:

func DownloadedLanguages() []string

Example:

result := DownloadedLanguages()

Returns: []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:

func CleanCache() error

Example:

if err := CleanCache(); err != nil {
    return err
}

Returns: No return value.

Errors: Returns error.

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:

func CacheDir() (string, error)

Example:

result, err := CacheDir()
if err != nil {
    return err
}

Returns: string

Errors: Returns error.

Types

ByteRange

A byte range — start (inclusive) to end (exclusive).

Field	Type	Default	Description
`Start`	`int`	—	Inclusive start byte offset.
`End`	`int`	—	Exclusive end byte offset.

ChunkContext

Metadata for a single chunk of source code.

Field	Type	Default	Description
`Language`	`string`	—	Language name used to parse this chunk.
`ChunkIndex`	`int`	—	Zero-indexed position of this chunk within the file’s chunk list.
`TotalChunks`	`int`	—	Total number of chunks the file was split into.
`NodeTypes`	`\[\]string`	`nil`	Tree-sitter node kinds that appear at the top level of this chunk.
`ContextPath`	`\[\]string`	`nil`	Hierarchical path of enclosing structural items (e.g., `\["MyClass", "my_method"\]`).
`SymbolsDefined`	`\[\]string`	`nil`	Names of symbols defined within this chunk.
`Comments`	`\[\]CommentInfo`	`nil`	Comments contained within this chunk.
`Docstrings`	`\[\]DocstringInfo`	`nil`	Docstrings contained within this chunk.
`HasErrorNodes`	`bool`	—	Whether this chunk contains any tree-sitter error nodes.

CodeChunk

A chunk of source code with rich metadata.

Field	Type	Default	Description
`Content`	`string`	—	The raw source text of this chunk.
`StartByte`	`int`	—	Inclusive start byte offset of this chunk in the original source.
`EndByte`	`int`	—	Exclusive end byte offset of this chunk in the original source.
`StartLine`	`int`	—	Zero-indexed start line of this chunk.
`EndLine`	`int`	—	Zero-indexed end line of this chunk.
`Metadata`	`ChunkContext`	—	Contextual metadata about this chunk.

CommentInfo

A comment extracted from source code.

Field	Type	Default	Description
`Text`	`string`	—	The raw text content of the comment.
`Kind`	`CommentKind`	`CommentKind.Line`	The kind of comment (line, block, or doc).
`Span`	`Span`	—	Source span covering the comment.
`AssociatedNode`	`*string`	`nil`	Name of the syntax node this comment is directly associated with.

DataAttribute

An XML-style attribute attached to an Element node.

Populated only for DataNodeKind.Element; always empty for KeyValue and Sequence nodes.

Field	Type	Default	Description
`Name`	`string`	—	Attribute name (e.g. `"class"`, `"href"`).
`Value`	`string`	—	Attribute value as a raw string (quotes stripped).
`Span`	`Span`	—	Source span covering the entire `name="value"` attribute token.

DataNode

A node in the hierarchical data tree produced by data-format extraction.

When ProcessConfig.data_extraction is true, ProcessResult.data is populated with a root DataNode whose children mirror the structure of the parsed file.

The kind field determines which other fields are meaningful:

`kind`	`key`	`value`	`attributes`	`children`
`KeyValue`	key / mapping key / index	leaf value	empty	nested map
`Element`	XML tag name	text content	XML attrs	child elements
`Sequence`	positional index (`"0"`)	leaf value	empty	sub-items

Field	Type	Default	Description
`Kind`	`DataNodeKind`	`DataNodeKind.KeyValue`	Whether this node is a key/value pair, XML element, or sequence item.
`Key`	`*string`	`nil`	Key, attribute name, tag name, or positional index (`"0"`, `"1"`, …). `nil` at the document root.
`Value`	`*string`	`nil`	Leaf scalar value, if any. `nil` for containers (objects, arrays, XML elements with child elements).
`Attributes`	`\[\]DataAttribute`	`nil`	Attributes on element-shape nodes (XML `STag` attributes). Empty for all other kinds.
`Children`	`\[\]DataNode`	`nil`	Children for nested containers and XML element bodies.
`Span`	`Span`	—	Source span covering this node in the original source file.

Diagnostic

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

Field	Type	Default	Description
`Message`	`string`	—	Human-readable description of the diagnostic.
`Severity`	`DiagnosticSeverity`	`DiagnosticSeverity.Error`	Severity of the diagnostic.
`Span`	`Span`	—	Source span where the diagnostic was detected.

DocSection

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

Field	Type	Default	Description
`Kind`	`string`	—	Section kind (e.g., `"args"`, `"returns"`, `"raises"`).
`Name`	`*string`	`nil`	Parameter or return value name, if applicable.
`Description`	`string`	—	Description text for this section.

DocstringInfo

A docstring extracted from source code.

Field	Type	Default	Description
`Text`	`string`	—	The raw text of the docstring.
`Format`	`DocstringFormat`	`DocstringFormat.PythonTripleQuote`	The docstring format (Python, JSDoc, Rustdoc, etc.).
`Span`	`Span`	—	Source span covering the docstring.
`AssociatedItem`	`*string`	`nil`	Name of the item this docstring documents.
`ParsedSections`	`\[\]DocSection`	`nil`	Parsed sections of the docstring (Args, Returns, Raises, etc.).

DownloadManager

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

Methods

New()

Create a new download manager for the given version.

Signature:

func (o *DownloadManager) New(version string) (DownloadManager, error)

Example:

result, err := DownloadManager.New("value")
if err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Version`	`string`	Yes	The version

Returns: DownloadManager

Errors: Returns error.

InstalledLanguages()

List languages that are already downloaded and cached.

Signature:

func (o *DownloadManager) InstalledLanguages() []string

Example:

result := instance.InstalledLanguages()

Returns: []string

DownloadAllBestEffort()

Download the platform bundle and extract every library file it contains.

Unlike Self.ensure_languages, this does not check the manifest language list against archive contents — it simply extracts all .so/.dylib/.dll files from the bundle. Languages in the manifest that are missing from the archive are silently ignored rather than returning an error.

Returns the number of library files extracted (including those already cached).

Signature:

func (o *DownloadManager) DownloadAllBestEffort() (int, error)

Example:

result, err := instance.DownloadAllBestEffort()
if err != nil {
    return err
}

Returns: int

Errors: Returns error.

CleanCache()

Remove all cached parser libraries.

Acquires the cross-process lock so clean_cache cannot race a concurrent downloader (avoids Windows sharing-violation errors against an in-flight bundle write). The .download.lock file itself is not removed — it is permanent infrastructure; deleting it could allow a concurrent process that already opened the file to continue holding a stale lock handle while a new process opens a fresh inode, breaking the mutual-exclusion guarantee.

Signature:

func (o *DownloadManager) CleanCache() error

Example:

if err := instance.CleanCache(); err != nil {
    return err
}

Returns: No return value.

Errors: Returns error.

ExportInfo

An export statement extracted from source code.

Field	Type	Default	Description
`Name`	`string`	—	The exported name.
`Kind`	`ExportKind`	`ExportKind.Named`	The kind of export (named, default, or re-export).
`Span`	`Span`	—	Source span covering the export statement.

FileMetrics

Aggregate metrics for a source file.

Field	Type	Default	Description
`TotalLines`	`int`	—	Total number of lines (including blank and comment lines).
`CodeLines`	`int`	—	Number of lines containing non-blank, non-comment source code.
`CommentLines`	`int`	—	Number of lines that are entirely comments.
`BlankLines`	`int`	—	Number of blank (whitespace-only) lines.
`TotalBytes`	`int`	—	Total byte length of the source file.
`NodeCount`	`int`	—	Total number of nodes in the syntax tree.
`ErrorCount`	`int`	—	Number of error nodes in the syntax tree (parse errors).
`MaxDepth`	`int`	—	Maximum nesting depth reached in the syntax tree.

ImportInfo

An import statement extracted from source code.

Field	Type	Default	Description
`Source`	`string`	—	The module or path being imported from.
`Items`	`\[\]string`	`nil`	Specific names imported from the source module.
`Alias`	`*string`	`nil`	Alias assigned to the import (e.g., `import numpy as np`).
`IsWildcard`	`bool`	—	Whether this is a wildcard import (e.g., `import ` or `use foo.`).
`Span`	`Span`	—	Source span covering the import statement.

Language

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 (get_language, available_languages, etc.).

Methods

New()

Create a new registry populated with all statically compiled languages.

When the dynamic-loading feature is enabled, the registry also knows about dynamically loadable grammars and will load them on demand.

Signature:

func (o *LanguageRegistry) New() LanguageRegistry

Example:

result := LanguageRegistry.New()

Returns: LanguageRegistry

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:

func (o *LanguageRegistry) GetLanguage(name string) (Language, error)

Example:

result, err := instance.GetLanguage("value")
if err != nil {
    return err
}

Parameters:

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

Returns: Language

Errors: Returns error.

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:

func (o *LanguageRegistry) AvailableLanguages() []string

Example:

result := instance.AvailableLanguages()

Returns: []string

HasParser()

Check whether a parser is statically compiled into this build.

Returns true only when the grammar was compiled in at build time (i.e. it appears in the STATIC_LANGUAGES table). This is independent of the extension-to-language mapping: detect_language_from_extension consults the static ext table for all 306 grammars regardless of which parsers are compiled in.

Use this when you need to distinguish “we know the language name” from “we can actually parse files in that language right now”.

use tree_sitter_language_pack::{detect_language_from_extension, LanguageRegistry};

let registry = LanguageRegistry::new();
// Extension detection uses the static table — independent of compiled parsers.
let lang = detect_language_from_extension("feature"); // always returns Some("gherkin")
// Parser availability depends on which grammars were compiled in.
let can_parse = lang.map(|name| registry.has_parser(name)).unwrap_or(false);

Signature:

func (o *LanguageRegistry) HasParser(name string) bool

Example:

result := instance.HasParser("value")

Parameters:

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

Returns: bool

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:

func (o *LanguageRegistry) HasLanguage(name string) bool

Example:

result := instance.HasLanguage("value")

Parameters:

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

Returns: bool

LanguageCount()

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

Signature:

func (o *LanguageRegistry) LanguageCount() int

Example:

result := instance.LanguageCount()

Returns: int

Process()

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

Signature:

func (o *LanguageRegistry) Process(source string, config ProcessConfig) (ProcessResult, error)

Example:

result, err := instance.Process("value", ProcessConfig{})
if err != nil {
    return err
}

Parameters:

Name	Type	Required	Description
`Source`	`string`	Yes	The source
`Config`	`ProcessConfig`	Yes	The configuration options

Returns: ProcessResult

Errors: Returns error.

Default()

Signature:

func (o *LanguageRegistry) Default() LanguageRegistry

Example:

result := LanguageRegistry.Default()

Returns: LanguageRegistry

Node

A single syntax node within a Tree.

Nodes hold a strong reference to their parent tree so they remain valid regardless of how the tree is moved or stored at the FFI boundary.

Methods

Clone()

Signature:

func (o *Node) Clone() Node

Example:

result := instance.Clone()

Returns: Node

Kind()

Return the node’s kind name (e.g. "function_definition").

Signature:

func (o *Node) Kind() string

Example:

result := instance.Kind()

Returns: string

KindId()

Return the node’s numeric kind ID.

Tree-sitter assigns a stable u16 ID to every node kind in a grammar (e.g. "function_definition" → 42). Comparing kind_id() is cheaper than comparing the string kind() in tight AST loops.

Signature:

func (o *Node) KindId() uint16

Example:

result := instance.KindId()

Returns: uint16

StartByte()

Return the inclusive start byte offset of this node.

Signature:

func (o *Node) StartByte() int

Example:

result := instance.StartByte()

Returns: int

EndByte()

Return the exclusive end byte offset of this node.

Signature:

func (o *Node) EndByte() int

Example:

result := instance.EndByte()

Returns: int

ByteRange()

Return the node’s byte range as a ByteRange.

Callers should slice their own source bytes — this is a zero-copy text accessor.

Signature:

func (o *Node) ByteRange() ByteRange

Example:

result := instance.ByteRange()

Returns: ByteRange

StartPosition()

Return the start Point (row, column).

Signature:

func (o *Node) StartPosition() Point

Example:

result := instance.StartPosition()

Returns: Point

EndPosition()

Return the end Point (row, column).

Signature:

func (o *Node) EndPosition() Point

Example:

result := instance.EndPosition()

Returns: Point

IsNamed()

True when this node is named (not punctuation/whitespace).

Signature:

func (o *Node) IsNamed() bool

Example:

result := instance.IsNamed()

Returns: bool

IsError()

True when this is an error node.

Signature:

func (o *Node) IsError() bool

Example:

result := instance.IsError()

Returns: bool

IsMissing()

True when this is a missing-token node.

Signature:

func (o *Node) IsMissing() bool

Example:

result := instance.IsMissing()

Returns: bool

IsExtra()

True when this is an “extra” node (e.g. a comment).

Signature:

func (o *Node) IsExtra() bool

Example:

result := instance.IsExtra()

Returns: bool

HasError()

True when this node or any descendant is an error.

Signature:

func (o *Node) HasError() bool

Example:

result := instance.HasError()

Returns: bool

Parent()

Return this node’s parent, if any.

Signature:

func (o *Node) Parent() *Node

Example:

result := instance.Parent()

Returns: *Node

Child()

Return the i-th child of this node, if any.

Signature:

func (o *Node) Child(index uint32) *Node

Example:

result := instance.Child(42)

Parameters:

Name	Type	Required	Description
`Index`	`uint32`	Yes	The index

Returns: *Node

ChildCount()

Total number of children (including unnamed).

Signature:

func (o *Node) ChildCount() int

Example:

result := instance.ChildCount()

Returns: int

NamedChild()

Return the i-th named child of this node, if any.

Signature:

func (o *Node) NamedChild(index uint32) *Node

Example:

result := instance.NamedChild(42)

Parameters:

Name	Type	Required	Description
`Index`	`uint32`	Yes	The index

Returns: *Node

NamedChildCount()

Number of named children of this node.

Signature:

func (o *Node) NamedChildCount() int

Example:

result := instance.NamedChildCount()

Returns: int

ChildByFieldName()

Look up a child by its grammar-defined field name.

Signature:

func (o *Node) ChildByFieldName(name string) *Node

Example:

result := instance.ChildByFieldName("value")

Parameters:

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

Returns: *Node

ToSexp()

Return the S-expression form of this node’s subtree.

Signature:

func (o *Node) ToSexp() string

Example:

result := instance.ToSexp()

Returns: string

Walk()

Return a TreeCursor positioned at this node.

Signature:

func (o *Node) Walk() TreeCursor

Example:

result := instance.Walk()

Returns: TreeCursor

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
`CacheDir`	`*string`	`nil`	Override default cache directory. Default: `~/.cache/tree-sitter-language-pack/v{version}/libs/`
`Languages`	`*\[\]string`	`nil`	Languages to pre-download on init. Each entry is a language name (e.g. `"python"`, `"rust"`).
`Groups`	`*\[\]string`	`nil`	Language groups to pre-download (e.g. `"web"`, `"systems"`, `"scripting"`).

Parser

A tree-sitter parser configured for one language at a time.

Methods

New()

Construct a new parser with no language set.

Call Parser.set_language before parsing.

Signature:

func (o *Parser) New() Parser

Example:

result := Parser.New()

Returns: Parser

SetLanguage()

Configure the parser to use the language identified by name (e.g. "python").

Resolves the language through the global registry — auto-downloading if necessary, when the download feature is enabled.

Errors:

Returns Error.LanguageNotFound if the language is not recognized, or Error.ParserSetup if the language ABI is incompatible.

Signature:

func (o *Parser) SetLanguage(name string) error

Example:

if err := instance.SetLanguage("value"); err != nil {
    return err
}

Parameters:

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

Returns: No return value.

Errors: Returns error.

Parse()

Parse a UTF-8 source string. Returns nil if parsing was cancelled or no language is set.

Signature:

func (o *Parser) Parse(source string) *Tree

Example:

result := instance.Parse("value")

Parameters:

Name	Type	Required	Description
`Source`	`string`	Yes	The source

Returns: *Tree

ParseBytes()

Parse a raw byte slice. Returns nil if parsing was cancelled or no language is set.

Signature:

func (o *Parser) ParseBytes(source []byte) *Tree

Example:

result := instance.ParseBytes([]byte("data"))

Parameters:

Name	Type	Required	Description
`Source`	`\[\]byte`	Yes	The source

Returns: *Tree

Reset()

Reset internal state. The next call to parse will not be incremental.

Signature:

func (o *Parser) Reset()

Example:

instance.Reset()

Returns: No return value.

Default()

Signature:

func (o *Parser) Default() Parser

Example:

result := Parser.Default()

Returns: Parser

Point

A source position — row + column, zero-indexed.

Field	Type	Default	Description
`Row`	`int`	—	Zero-indexed row number.
`Column`	`int`	—	Zero-indexed column number, in UTF-16 code units.

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.
`ChunkMaxSize`	`*int`	`nil`	Maximum chunk size in bytes. `nil` disables chunking.
`DataExtraction`	`bool`	`false`	Extract hierarchical key/value data tree from data-format files. Default: false. When `true`, `ProcessResult.data` is populated with a `DataNode` tree for supported languages: JSON, YAML, TOML, `.properties`, HCL/HOCON, INI, editorconfig, KDL, CUE, CSV, PSV, PO, nginx config, Caddy config, XML, and DTD. For languages outside this set the field is left as `nil`.

Methods

Default()

Signature:

func (o *ProcessConfig) Default() ProcessConfig

Example:

result := ProcessConfig.Default()

Returns: ProcessConfig

WithChunking()

Enable chunking with the given maximum chunk size in bytes.

Signature:

func (o *ProcessConfig) WithChunking(maxSize int) ProcessConfig

Example:

result := instance.WithChunking(42)

Parameters:

Name	Type	Required	Description
`MaxSize`	`int`	Yes	The max size

Returns: ProcessConfig

All()

Enable all analysis features.

Signature:

func (o *ProcessConfig) All() ProcessConfig

Example:

result := instance.All()

Returns: ProcessConfig

Minimal()

Disable all analysis features (only metrics computed).

Signature:

func (o *ProcessConfig) Minimal() ProcessConfig

Example:

result := instance.Minimal()

Returns: ProcessConfig

WithDataExtraction()

Enable or disable hierarchical data extraction for data-format files.

When true, ProcessResult.data is populated with a key/value tree for supported data-format languages.

Signature:

func (o *ProcessConfig) WithDataExtraction(enabled bool) ProcessConfig

Example:

result := instance.WithDataExtraction(true)

Parameters:

Name	Type	Required	Description
`Enabled`	`bool`	Yes	The enabled

Returns: 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 ProcessConfig flags.

Field	Type	Default	Description
`Language`	`string`	—	The language name used to parse the source file.
`Metrics`	`FileMetrics`	—	File-level metrics (line counts, byte size, error count).
`Structure`	`\[\]StructureItem`	`nil`	Top-level structural items (functions, classes, etc.).
`Imports`	`\[\]ImportInfo`	`nil`	Import statements extracted from the source.
`Exports`	`\[\]ExportInfo`	`nil`	Export statements extracted from the source.
`Comments`	`\[\]CommentInfo`	`nil`	Comments extracted from the source.
`Docstrings`	`\[\]DocstringInfo`	`nil`	Docstrings extracted from the source.
`Symbols`	`\[\]SymbolInfo`	`nil`	Symbol definitions (variables, types, functions) extracted from the source.
`Diagnostics`	`\[\]Diagnostic`	`nil`	Parse diagnostics (syntax errors, missing nodes) from tree-sitter.
`Chunks`	`\[\]CodeChunk`	`nil`	Syntax-aware code chunks produced when chunking is enabled.
`Data`	`*DataNode`	`nil`	Hierarchical data tree extracted when `config.data_extraction` is `true`. Populated for supported data-format languages (JSON, YAML, TOML, properties, HCL, INI, XML, CSV, and more). `nil` when `data_extraction` is `false` (the default) or when the language is not a recognised data format. See `DataNode` for the shape of the returned tree.

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
`StartByte`	`int`	—	Inclusive start byte offset in the source.
`EndByte`	`int`	—	Exclusive end byte offset in the source.
`StartLine`	`int`	—	Zero-indexed line number of the span’s start.
`StartColumn`	`int`	—	Zero-indexed column number of the span’s start.
`EndLine`	`int`	—	Zero-indexed line number of the span’s end.
`EndColumn`	`int`	—	Zero-indexed column number of the span’s end.

StructureItem

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

Field	Type	Default	Description
`Kind`	`StructureKind`	`StructureKind.Function`	The kind of structural item.
`Name`	`*string`	`nil`	The declared name of the item, if present.
`Visibility`	`*string`	`nil`	Visibility modifier (e.g., `"pub"`, `"public"`, `"private"`).
`Span`	`Span`	—	Source span covering the entire item declaration.
`Children`	`\[\]StructureItem`	`nil`	Nested structural items (e.g., methods within a class).
`Decorators`	`\[\]string`	`nil`	Decorator or attribute names applied to the item.
`DocComment`	`*string`	`nil`	Documentation comment attached to the item, if any.
`Signature`	`*string`	`nil`	Full signature text of the item (e.g., function parameters and return type).
`BodySpan`	`*Span`	`nil`	Source span covering only the body of the item, if distinct from the declaration.

SymbolInfo

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

Field	Type	Default	Description
`Name`	`string`	—	The name of the symbol.
`Kind`	`SymbolKind`	`SymbolKind.Variable`	The kind of symbol (variable, function, class, etc.).
`Span`	`Span`	—	Source span covering the symbol definition.
`TypeAnnotation`	`*string`	`nil`	Explicit type annotation, if present in the source.
`Doc`	`*string`	`nil`	Documentation comment associated with this symbol.

Tree

A parsed syntax tree. Cheap to clone (refcount bump).

Methods

RootNode()

Return the root Node of this tree.

Signature:

func (o *Tree) RootNode() Node

Example:

result := instance.RootNode()

Returns: Node

Walk()

Return a TreeCursor positioned at the root.

Signature:

func (o *Tree) Walk() TreeCursor

Example:

result := instance.Walk()

Returns: TreeCursor

TreeCursor

A cursor for traversing a Tree.

Methods

Node()

Return the Node at the cursor’s current position.

Signature:

func (o *TreeCursor) Node() Node

Example:

result := instance.Node()

Returns: Node

GotoFirstChild()

Move the cursor to the first child of the current node. Returns true if a child existed.

Signature:

func (o *TreeCursor) GotoFirstChild() bool

Example:

result := instance.GotoFirstChild()

Returns: bool

GotoParent()

Move the cursor to the parent of the current node. Returns true if a parent existed.

Signature:

func (o *TreeCursor) GotoParent() bool

Example:

result := instance.GotoParent()

Returns: bool

GotoNextSibling()

Move the cursor to the next sibling of the current node. Returns true if a sibling existed.

Signature:

func (o *TreeCursor) GotoNextSibling() bool

Example:

result := instance.GotoNextSibling()

Returns: bool

FieldName()

Return the field name for the current node, if any.

Signature:

func (o *TreeCursor) FieldName() *string

Example:

result := instance.FieldName()

Returns: *string

Enums

DataNodeKind

The kind of a data node extracted from a data-format file.

Classifies each node in the hierarchical DataNode tree returned when data_extraction is enabled on ProcessConfig.

Wire format (public JSON contract)

Unit variants serialize as a bare string ("KeyValue"). DO NOT add #[serde(tag = "...")] or rename variants — every language binding has a hand-written deserializer matching this exact shape, and any change breaks all bindings’ process() tests simultaneously. Covered by tests/wire_format.rs.

Value	Description
`KeyValue`	A key/value pair or mapping (json/toml/properties/yaml/hcl/cue/kdl pair, or a wrapper “object”/“mapping” container).
`Element`	An XML element with a tag name in `key` and attributes in `attributes`.
`Sequence`	A positional sequence item (JSON array element, YAML block sequence item, CSV/PSV row or cell).

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.

Wire format (public JSON contract)

Unit variants serialize as a bare string ("Function"); the Other variant serializes as a single-keyed object ({"Other": "macro"}). DO NOT add #[serde(tag = "...")] or rename variants — every language binding has a hand-written deserializer matching this exact shape, and any change breaks all bindings’ process() tests simultaneously. Covered by tests/wire_format.rs.

Value	Description
`Function`	A free-standing or associated function.
`Method`	A method defined inside a class, struct, trait, or impl block.
`Class`	A class definition.
`Struct`	A struct definition.
`Interface`	An interface or protocol definition.
`Enum`	An enum definition.
`Module`	A module or package declaration.
`Trait`	A trait definition.
`Impl`	An impl block (Rust) or similar implementation block.
`Namespace`	A namespace declaration.
`Other`	A language-specific construct that does not fit any standard category. — 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`	A single-line comment (e.g., `// ...` or `# ...`).
`Block`	A block or multi-line comment using slash-star delimiters.
`Doc`	A documentation comment such as `/// ...` or slash-double-star block.

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).

Wire format (public JSON contract)

Unit variants serialize as a bare string ("JSDoc"); the Other variant serializes as a single-keyed object ({"Other": "rst"}). DO NOT add #[serde(tag = "...")]. Covered by tests/wire_format.rs.

Value	Description
`PythonTripleQuote`	Python triple-quoted string docstring (`"""..."""`).
`JsDoc`	JavaScript/TypeScript JSDoc block comment (opens with two stars, closes with star-slash).
`Rustdoc`	Rust `///` or `//!` doc comment.
`GoDoc`	Go doc comment (a comment block immediately preceding a declaration).
`JavaDoc`	Java Javadoc block comment (opens with two stars, closes with star-slash).
`Other`	A language-specific docstring format not covered by the standard variants. — 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`	A named export (e.g., `export { foo }`).
`Default`	A default export (e.g., `export default foo`).
`ReExport`	A re-export from another module (e.g., `export { foo } from 'bar'`).

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.

Wire format (public JSON contract)

Unit variants serialize as a bare string ("Function"); the Other variant serializes as a single-keyed object ({"Other": "macro"}). DO NOT add #[serde(tag = "...")]. Covered by tests/wire_format.rs.

Value	Description
`Variable`	A variable binding.
`Constant`	A constant (immutable binding).
`Function`	A function definition.
`Class`	A class definition.
`Type`	A type alias or typedef.
`Interface`	An interface definition.
`Enum`	An enum definition.
`Module`	A module declaration.
`Other`	A symbol kind not covered by the standard variants. — 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`	A parse error (e.g., an `ERROR` or `MISSING` node in the tree).
`Warning`	A warning-level diagnostic.
`Info`	An informational diagnostic.

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`	The requested language name (or alias) was not found in the registry.
`DynamicLoad`	A dynamic shared library could not be loaded at runtime.
`NullLanguagePointer`	The tree-sitter language function returned a null pointer for the given language name.
`ParserSetup`	The language could not be applied to the parser (e.g., ABI version mismatch).
`LockPoisoned`	An internal `RwLock` or `Mutex` was poisoned by a previous panic.
`Config`	A configuration file or value was invalid or could not be applied.
`ParseFailed`	The tree-sitter parser returned no tree for the given source input.
`QueryError`	A tree-sitter query could not be compiled or executed.
`InvalidRange`	A byte range was invalid (e.g., end before start, or out of bounds).
`Download`	A parser download from GitHub releases failed.
`ChecksumMismatch`	The downloaded file’s SHA-256 digest did not match the manifest’s expected value.
`CacheLock`	The cross-process download cache lock file could not be acquired or created.