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 Zulip server, so we can help you with any question you might have! There is also a Matrix channel for tree-sitter support in Neovim.
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-push
If 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 Zulip or 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 thehighlight
module.locals.scm
: used to extract keyword definitions, scopes, references, etc, using thelocals
module.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-ui
within 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).
As languages differ quite a lot, here is a set of captures available to you when building a highlights.scm
query.
One important thing to note is that many of these capture groups are not supported by neovim
for now, and will not have any
effect on highlighting. We will work on improving highlighting in the near future though.
@comment ; line and block comments
@error ; syntax/parser errors
@none ; completely disable the highlight
@preproc ; various preprocessor directives & shebangs
@define ; preprocessor definition directives
@operator ; symbolic operators (e.g. `+` / `*`)
@punctuation.delimiter ; delimiters (e.g. `;` / `.` / `,`)
@punctuation.bracket ; brackets (e.g. `()` / `{}` / `[]`)
@punctuation.special ; special symbols (e.g. `{}` in string interpolation)
@string ; string literals
@string.regex ; regular expressions
@string.escape ; escape sequences
@string.special ; other special strings (e.g. dates)
@character ; character literals
@character.special ; special characters (e.g. wildcards)
@boolean ; boolean literals
@number ; numeric literals
@float ; floating-point number literals
@function ; function definitions
@function.builtin ; built-in functions
@function.call ; function calls
@function.macro ; preprocessor macros
@method ; method definitions
@method.call ; method calls
@constructor ; constructor calls and definitions
@parameter ; parameters of a function
@keyword ; various keywords
@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.return ; keywords like `return` and `yield`
@conditional ; keywords related to conditionals (e.g. `if` / `else`)
@conditional.ternary ; Ternary operator: condition ? 1 : 2
@repeat ; keywords related to loops (e.g. `for` / `while`)
@debug ; keywords related to debugging
@label ; GOTO and other labels (e.g. `label:` in C)
@include ; keywords for including modules (e.g. `import` / `from` in Python)
@exception ; keywords related to exceptions (e.g. `throw` / `catch`)
@type ; type or class definitions and annotations
@type.builtin ; built-in types
@type.definition ; type definitions (e.g. `typedef` in C)
@type.qualifier ; type qualifiers (e.g. `const`)
@storageclass ; visibility/life-time modifiers
@attribute ; attribute annotations (e.g. Python decorators)
@field ; object and struct fields
@property ; similar to `@field`
@variable ; various variable names
@variable.builtin ; built-in variable names (e.g. `this`)
@constant ; constant identifiers
@constant.builtin ; built-in constant values
@constant.macro ; constants defined by the preprocessor
@namespace ; modules or namespaces
@symbol ; symbols or atoms
Mainly for markup languages.
@text ; non-structured text
@text.strong ; bold text
@text.emphasis ; text with emphasis
@text.underline ; underlined text
@text.strike ; strikethrough text
@text.title ; text that is part of a title
@text.literal ; literal or verbatim text
@text.uri ; URIs (e.g. hyperlinks)
@text.math ; math environments (e.g. `$ ... $` in LaTeX)
@text.environment ; text environments of markup languages
@text.environment.name ; text indicating the type of an environment
@text.reference ; text references, footnotes, citations, etc.
@text.todo ; todo notes
@text.note ; info notes
@text.warning ; warning notes
@text.danger ; danger/error notes
@text.diff.add ; added text (for diff files)
@text.diff.delete ; deleted text (for diff files)
Used for XML-like tags.
@tag ; XML tag names
@tag.attribute ; XML tag attributes
@tag.delimiter ; XML tag delimiters
@conceal ; for captures that are only used for concealing
@conceal
must be followed by (#set! conceal "")
.
@spell ; for defining regions to be spellchecked
@nospell ; for defining regions that should NOT be spellchecked
@definition ; various definitions
@definition.constant ; constants
@definition.function ; functions
@definition.method ; methods
@definition.var ; variables
@definition.parameter ; parameters
@definition.macro ; preprocessor macros
@definition.type ; types or classes
@definition.field ; fields or properties
@definition.enum ; enumerations
@definition.namespace ; modules or namespaces
@definition.import ; imported names
@definition.associated ; the associated type of a variable
@scope ; scope block
@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) @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 @scope
captures in the locals
query.
Some captures are related to language injection (like markdown code blocks). They are used in injections.scm
.
You can directly use the name of the language that you want to inject (e.g. @html
to inject html).
If you want to dynamically detect the language (e.g. for Markdown blocks) use the @language
to capture
the node describing the language and @content
to describe the injection region.
@{lang} ; e.g. @html to describe a html region
@language ; dynamic detection of the injection language (i.e. the text of the captured node describes the language)
@content ; region for the dynamically detected language
@combined ; combine all matches of a pattern as one single block of content
@indent ; indent children when matching this node
@indent_end ; marks the end of indented block
@aligned_indent ; behaves like python aligned/hanging indent
@dedent ; dedent children when matching this node
@branch ; dedent itself when matching this node
@ignore ; do not indent in this node
@auto ; behaves like 'autoindent' buffer option
@zero_indent ; sets this node at position 0 (no indent)