First of all, thank you very much for contributing to nvim-treesitter.
If you haven't already, you should really come and reach out to us on our Matrix channel, so we can help you with any question you might have!
As you know, nvim-treesitter is roughly split in two parts:
- Parser configurations : for various things like
locals,highlights - What we like to call modules : tiny Lua modules that provide a given feature, based on parser configurations
Depending on which part of the plugin you want to contribute to, please read the appropriate section.
We haven't implemented any functional tests yet. Feel free to contribute.
However, we check code style with luacheck and stylua!
Please install luacheck and activate our pre-push hook to automatically check style before
every push:
luarocks install luacheck
cargo install stylua
ln -s ../../scripts/pre-push .git/hooks/pre-pushIf you want to see a new functionality added to nvim-treesitter feel free to first open an issue
to that we can track our solution!
Thus far, there is basically two types of modules:
- Little modules (like
incremental selection) that are built innvim-treesitter, we call thembuiltin modules. - Bigger modules (like
completion-treesitter, ornvim-tree-docs), or modules that integrate with other plugins, that we callremote modules.
In any case, you can build your own module! To help you started in the process, we have a template repository designed to build new modules here. Feel free to use it, and contact us over on our on the "Neovim tree-sitter" Matrix channel.
Contributing to parser configurations is basically modifying one of the queries/*/*.scm.
Each of these scheme files contains a tree-sitter query for a given purpose.
Before going any further, we highly suggest that you read more about tree-sitter queries.
Each query has an appropriate name, which is then used by modules to extract data from the syntax tree.
For now these are the types of queries used by nvim-treesitter:
highlights.scm: used for syntax highlighting, using thehighlightmodule.locals.scm: used to extract keyword definitions, scopes, references, etc, using thelocalsmodule.textobjects.scm: used to define text objects.folds.scm: used to define folds.injections.scm: used to define injections.
For these types there is a norm you will have to follow so that features work fine. Here are some global advices:
- If your language is listed here, you can install the playground plugin.
- If your language is listed here, you can debug and experiment with your queries there.
- If not, you should consider installing the tree-sitter CLI,
you should then be able to open a local playground using
tree-sitter build-wasm && tree-sitter web-uiwithin the parsers repo. - Examples of queries can be found in queries/
- Matches in the bottom will override queries that are above of them.
If your language is an extension of a language (TypeScript is an extension of JavaScript for example), you can include the queries from your base language by adding the following as the first line of your file.
; inherits: lang1,(optionallang)
If you want to inherit a language, but don't want the languages inheriting from yours to inherit it, you can mark the language as optional (by putting it between parenthesis).
All queries are expected to follow a standard format, with every node on a single line and indented by two spaces for each level of nesting. You can automatically format the bundled queries by running the provided formatter ./scripts/format-queries.lua on a single file (ending in .scm) or directory to format.
Should you need to preserve a specific format for a node, you can exempt it (and all contained nodes) by placing before it
; format-ignore
As languages differ quite a lot, here is a set of captures available to you when building a highlights.scm query. Note that your color scheme needs to define (or link) these captures as highlight groups.
@variable ; various variable names
@variable.builtin ; built-in variable names (e.g. `this`)
@variable.parameter ; parameters of a function
@variable.parameter.builtin ; special parameters (e.g. `_`, `it`)
@variable.member ; object and struct fields
@constant ; constant identifiers
@constant.builtin ; built-in constant values
@constant.macro ; constants defined by the preprocessor
@module ; modules or namespaces
@module.builtin ; built-in modules or namespaces
@label ; GOTO and other labels (e.g. `label:` in C), including heredoc labels
@string ; string literals
@string.documentation ; string documenting code (e.g. Python docstrings)
@string.regexp ; regular expressions
@string.escape ; escape sequences
@string.special ; other special strings (e.g. dates)
@string.special.symbol ; symbols or atoms
@string.special.url ; URIs (e.g. hyperlinks)
@string.special.path ; filenames
@character ; character literals
@character.special ; special characters (e.g. wildcards)
@boolean ; boolean literals
@number ; numeric literals
@number.float ; floating-point number literals
@type ; type or class definitions and annotations
@type.builtin ; built-in types
@type.definition ; identifiers in type definitions (e.g. `typedef <type> <identifier>` in C)
@attribute ; attribute annotations (e.g. Python decorators, Rust lifetimes)
@attribute.builtin ; builtin annotations (e.g. `@property` in Python)
@property ; the key in key/value pairs
@function ; function definitions
@function.builtin ; built-in functions
@function.call ; function calls
@function.macro ; preprocessor macros
@function.method ; method definitions
@function.method.call ; method calls
@constructor ; constructor calls and definitions
@operator ; symbolic operators (e.g. `+` / `*`)
@keyword ; keywords not fitting into specific categories
@keyword.coroutine ; keywords related to coroutines (e.g. `go` in Go, `async/await` in Python)
@keyword.function ; keywords that define a function (e.g. `func` in Go, `def` in Python)
@keyword.operator ; operators that are English words (e.g. `and` / `or`)
@keyword.import ; keywords for including modules (e.g. `import` / `from` in Python)
@keyword.type ; keywords describing namespaces and composite types (e.g. `struct`, `enum`)
@keyword.modifier ; keywords modifying other constructs (e.g. `const`, `static`, `public`)
@keyword.repeat ; keywords related to loops (e.g. `for` / `while`)
@keyword.return ; keywords like `return` and `yield`
@keyword.debug ; keywords related to debugging
@keyword.exception ; keywords related to exceptions (e.g. `throw` / `catch`)
@keyword.conditional ; keywords related to conditionals (e.g. `if` / `else`)
@keyword.conditional.ternary ; ternary operator (e.g. `?` / `:`)
@keyword.directive ; various preprocessor directives & shebangs
@keyword.directive.define ; preprocessor definition directives
@punctuation.delimiter ; delimiters (e.g. `;` / `.` / `,`)
@punctuation.bracket ; brackets (e.g. `()` / `{}` / `[]`)
@punctuation.special ; special symbols (e.g. `{}` in string interpolation)
@comment ; line and block comments
@comment.documentation ; comments documenting code
@comment.error ; error-type comments (e.g. `ERROR`, `FIXME`, `DEPRECATED`)
@comment.warning ; warning-type comments (e.g. `WARNING`, `FIX`, `HACK`)
@comment.todo ; todo-type comments (e.g. `TODO`, `WIP`)
@comment.note ; note-type comments (e.g. `NOTE`, `INFO`, `XXX`)
Mainly for markup languages.
@markup.strong ; bold text
@markup.italic ; italic text
@markup.strikethrough ; struck-through text
@markup.underline ; underlined text (only for literal underline markup!)
@markup.heading ; headings, titles (including markers)
@markup.heading.1 ; top-level heading
@markup.heading.2 ; section heading
@markup.heading.3 ; subsection heading
@markup.heading.4 ; and so on
@markup.heading.5 ; and so forth
@markup.heading.6 ; six levels ought to be enough for anybody
@markup.quote ; block quotes
@markup.math ; math environments (e.g. `$ ... $` in LaTeX)
@markup.link ; text references, footnotes, citations, etc.
@markup.link.label ; link, reference descriptions
@markup.link.url ; URL-style links
@markup.raw ; literal or verbatim text (e.g. inline code)
@markup.raw.block ; literal or verbatim text as a stand-alone block
; (use priority 90 for blocks with injections)
@markup.list ; list markers
@markup.list.checked ; checked todo-style list markers
@markup.list.unchecked ; unchecked todo-style list markers
@diff.plus ; added text (for diff files)
@diff.minus ; deleted text (for diff files)
@diff.delta ; changed text (for diff files)
@tag ; XML-style tag names (and similar)
@tag.builtin ; builtin tag names (e.g. HTML5 tags)
@tag.attribute ; XML-style tag attributes
@tag.delimiter ; XML-style tag delimiters
@none ; completely disable the highlight
@conceal ; captures that are only meant to be concealed
@spell ; for defining regions to be spellchecked
@nospell ; for defining regions that should NOT be spellchecked
The main types of nodes which are spell checked are:
- Comments
- Strings; where it makes sense. Strings that have interpolation or are typically used for non text purposes are not spell checked (e.g. bash).
Captures can be restricted according to node contents using predicates. For performance reasons, prefer earlier predicates in this list:
#eq?(literal match)#any-of?(one of several literal matches)#lua-match?(match against a Lua pattern)#match?/#vim-match?(match against a Vim regular expression
Captures can be concealed by setting the conceal metadata, e.g..,
(fenced_code_block_delimiter @markup.raw.block (#set! conceal ""))
The capture should be meaningful to allow proper highlighting when set conceallevel=0. If the unconcealed capture should not be highlighted (e.g., because an earlier pattern handles this), you can use @conceal.
A conceal can be restricted to part of the capture via the #offset! directive.
Captures can be assigned a priority to control precedence of highlights via the
#set! "priority" <number> directive (see :h treesitter-highlight-priority).
The default priority for treesitter highlights is 100; queries should only
set priorities between 90 and 120, to avoid conflict with other sources of
highlighting (such as diagnostics or LSP semantic tokens).
Locals are used to keep track of definitions and references in local or global scopes, see upstream documentation. Note that nvim-treesitter uses more specific subcaptures for definitions and does not use locals for highlighting.
@local.definition ; various definitions
@local.definition.constant ; constants
@local.definition.function ; functions
@local.definition.method ; methods
@local.definition.var ; variables
@local.definition.parameter ; parameters
@local.definition.macro ; preprocessor macros
@local.definition.type ; types or classes
@local.definition.field ; fields or properties
@local.definition.enum ; enumerations
@local.definition.namespace ; modules or namespaces
@local.definition.import ; imported names
@local.definition.associated ; the associated type of a variable
@local.scope ; scope block
@local.reference ; identifier reference
You can set the scope of a definition by setting the scope property on the definition.
For example, a JavaScript function declaration creates a scope. The function name is captured as the definition. This means that the function definition would only be available WITHIN the scope of the function, which is not the case. The definition can be used in the scope the function was defined in.
function doSomething() {}
doSomething(); // Should point to the declaration as the definition(function_declaration
((identifier) @local.definition.var)
(#set! "definition.var.scope" "parent"))
Possible scope values are:
parent: The definition is valid in the containing scope and one more scope above that scopeglobal: The definition is valid in the root scopelocal: The definition is valid in the containing scope. This is the default behavior
You can define folds for a given language by adding a folds.scm query :
@fold ; fold this node
If the folds.scm query is not present, this will fall back to the @local.scope captures in the locals
query.
Some captures are related to language injection (like markdown code blocks). They are used in injections.scm.
If you want to dynamically detect the language (e.g. for Markdown blocks) use the @injection.language to capture
the node describing the language and @injection.content to describe the injection region.
@injection.language ; dynamic detection of the injection language (i.e. the text of the captured node describes the language)
@injection.content ; region for the dynamically detected language
For example, to inject javascript into HTML's <script> tag
<script>someJsCode();</script>(script_element
(raw_text) @injection.content
(#set! injection.language "javascript")) ; set the parser language for @injection.content region to javascript
For regions that don't have a corresponding @injection.language, you need to manually set the language
through (#set injection.language "lang_name")
To combine all matches of a pattern as one single block of content, add (#set! injection.combined) to such pattern
@indent.begin ; indent children when matching this node
@indent.end ; marks the end of indented block
@indent.align ; behaves like python aligned/hanging indent
@indent.dedent ; dedent children when matching this node
@indent.branch ; dedent itself when matching this node
@indent.ignore ; do not indent in this node
@indent.auto ; behaves like 'autoindent' buffer option
@indent.zero ; sets this node at position 0 (no indent)