boilerplate for a rust language server powered by tower-lsp

Note

This repo uses l-lang, a simple statically-typed programming language with structs, functions, and expressions.

Tip

If you want a chumsky based language implementation, please check out the tag v1.0.0

A valid program in l-lang

struct Point {
    x: int,
    y: int,
}

struct Rectangle {
    top_left: Point,
    bottom_right: Point,
}

fn add_points(a: Point, b: Point) -> Point {
    return Point { x: a.x + b.x, y: a.y + b.y };
}

fn main() {
    let p1 = Point { x: 10, y: 20 };
    let p2 = Point { x: 5, y: 15 };
    let result = add_points(p1, p2);

    let rect = Rectangle {
        top_left: Point { x: 0, y: 100 },
        bottom_right: Point { x: 100, y: 0 },
    };

    return result;
}

Language Features

L-lang is a statically-typed language that supports:

• Struct definitions with typed fields
• Functions with typed parameters and return types
• Variable bindings with type inference
• Arithmetic operations (+, -, *, /)
• Field access for structs
• Struct literals for instantiation
• Basic types: int, bool, string

Introduction

This repo is a template for building Language Server Protocol (LSP) implementations using tower-lsp, demonstrating how to create language servers with full IDE support.

Development using VSCode

1. pnpm i
2. cargo build
3. Open the project in VSCode: code .
4. In VSCode, press F5 or change to the Debug panel and click Launch Client.
5. In the newly launched VSCode instance, open the file examples/test.l from this project.
6. If the LSP is working correctly you should see syntax highlighting and the features described below should work.

Note

If encountered errors like Cannot find module '/xxx/xxx/dist/extension.js' please try run command tsc -b manually, you could refer #6 for more details

Preview and test extension locally with VsCode

1. Make sure all dependency are installed.
2. Make sure the l-language-server is under your PATH
3. pnpm run package
4. code --install-extension l-language-server-${version}.vsix, the version you could inspect in file system.
5. Restart the VsCode, and write a minimal L file, then inspect the effect.

For other editor, please refer the related manual, you could skip steps above.

Features

This Language Server Protocol implementation for l-lang provides comprehensive IDE support with the following features:

Semantic Tokens

Syntax highlighting based on semantic analysis. Functions, variables, parameters, structs, and fields are highlighted according to their semantic roles.

Make sure semantic highlighting is enabled in your editor settings:

{
  "editor.semanticHighlighting.enabled": true
}

Inlay Hints

Type annotations for variables.

inlay_hint_compressed.mp4

Syntactic and Semantic Error Diagnostics

Real-time error reporting.

diagnostic_compressed.mp4

Code Completion

Context-aware suggestions for symbols.

completion_compressed.mp4

Go to Definition

Navigate to symbol declarations.

definition_compressed.mp4

Find References

Locate all usages of a symbol.

reference_compressed.mp4

Rename

Rename symbols across the entire codebase.

rename_compressed.mp4

Format

format_compressed.mp4