Language Support

Lucerna ships custom AST-aware chunkers for popular languages. Files in any other language are not indexed.

.gitignore is always respected. Lucerna discovers all .gitignore files in the project tree (root and subdirectories) and applies their patterns to both indexing and file watching.

Chunking quality per language

Language	Extensions	Chunks	Graph edges
TypeScript / JavaScript	.ts, .tsx, .js, .jsx	Imports, functions, generators, arrow functions, classes, methods, interfaces, type aliases	IMPORTS, DEFINES, EXTENDS, CALLS
Python	.py, .pyw	Imports, classes, functions (including class methods with className)	IMPORTS, DEFINES, EXTENDS, CALLS
Java	.java	Imports, classes, interfaces, enums (type), methods	IMPORTS, DEFINES, EXTENDS, IMPLEMENTS, CALLS
Go	.go	Imports, functions, receiver methods (method), structs (class), interfaces, type declarations	IMPORTS, DEFINES, CALLS
Rust	.rs	Imports (use), structs (class), enums (type), traits (interface), impl blocks (class), functions	IMPORTS, DEFINES, CALLS
C#	.cs	Imports (using), classes, records (class), structs (class), interfaces, enums (type), methods	IMPORTS, DEFINES, EXTENDS, CALLS
Swift	.swift	Imports, classes + structs (class), protocols (interface), enums (type), functions/methods	IMPORTS, DEFINES, EXTENDS, CALLS
Kotlin	.kt, .kts	Imports, classes + interfaces (class), functions/methods	IMPORTS, DEFINES, EXTENDS, IMPLEMENTS, CALLS
Ruby	.rb	Imports (require/require_relative), classes, modules (class), methods	IMPORTS, DEFINES, EXTENDS, CALLS
PHP	.php	Imports (use), functions, classes, interfaces, traits (interface), methods	IMPORTS, DEFINES, EXTENDS, IMPLEMENTS, CALLS
C	.c, .h	Includes (#include), functions, structs (class)	IMPORTS, DEFINES, CALLS
C++	.cpp, .cc, .cxx, .hpp	Includes (#include), classes, functions/methods	IMPORTS, DEFINES, EXTENDS, CALLS
Bash / Shell	.sh, .bash	Source imports (source/.), functions	IMPORTS, DEFINES, CALLS
Scala	.scala	Imports, classes, objects (class), traits (interface), methods	IMPORTS, DEFINES, EXTENDS, CALLS
Lua	.lua	Requires (require()), functions, local functions	IMPORTS, DEFINES, CALLS
R	.r, .R	Library imports (library()/require()), functions	IMPORTS, DEFINES, CALLS
Dart	.dart	Imports, classes, functions/methods	IMPORTS, DEFINES, EXTENDS, CALLS
Haskell	.hs	Imports, functions, data types (type), type classes (class)	IMPORTS, DEFINES, CALLS
Elixir	.ex, .exs	Aliases/imports, modules (class), def/defp functions/methods	IMPORTS, DEFINES, CALLS
Clojure	.clj, .cljs, .cljc	ns form (import chunk), defn/defn-/defmacro functions	IMPORTS, DEFINES, CALLS
Groovy	.groovy, .gradle	Imports, classes, methods	IMPORTS, DEFINES, CALLS
Perl	.pl, .pm	use imports, subroutines	IMPORTS, DEFINES, CALLS
PowerShell	.ps1, .psm1	using imports, functions, classes/methods	IMPORTS, DEFINES, CALLS
MATLAB	.m	Functions, classdefs and methods	DEFINES, CALLS
Zig	.zig	@import declarations, functions	IMPORTS, DEFINES, CALLS
Solidity	.sol	Imports, contracts (class), interfaces, functions/methods, events/modifiers (type)	IMPORTS, DEFINES, EXTENDS, CALLS
SQL	.sql	Statement-level chunks: CREATE TABLE, CREATE VIEW, SELECT, INSERT, UPDATE, DELETE	—
JSON	.json	Top-level key splitting for large files; single chunk for small files	—
Markdown	.md, .mdx	Heading-based sections (H1–H3) with full breadcrumbs	—
XML	.xml, .xsd, .xsl	Top-level element splitting for large files; single chunk for small files	—
TOML	.toml	Table splitting by [section] / [[array]] headers	—
YAML	.yaml, .yml	Top-level key splitting	—
HTML	.html, .htm	Top-level element splitting (like XML)	—
CSS	.css	Rule-set splitting by selector	—
SCSS	.scss	Rule-set splitting; named @mixin and @function definitions	—
Vue	.vue	One chunk per top-level block: <script>, <template>, <style>	—
Svelte	.svelte	One chunk per block: <script>, <style>, remaining markup as template	—
Julia	.jl	Imports, functions, structs (class), modules (class)	IMPORTS, DEFINES, CALLS
OCaml	.ml, .mli	Imports (open), let bindings, type definitions, modules	IMPORTS, DEFINES
Erlang	.erl	Module/export attributes (import), functions	IMPORTS, DEFINES, CALLS
Objective-C	.m, .mm	Imports (#import), interfaces, implementations, methods	IMPORTS, DEFINES, CALLS
All other languages	—	Not indexed	—

DEFINES edges link the import chunk to every named symbol in the same file. EXTENDS/IMPLEMENTS edges are emitted when inheritance syntax is present and the grammar supports it.

Lazy grammar loading

Grammar modules are loaded on first encounter — no configuration needed. Lucerna automatically initializes any language the first time it sees a file of that type.