glsp

GLSP

Language Server Protocol SDK for Go.

Fork of tliron/glsp -- thanks to Tal Liron for the original work. Adds fixes and LSP 3.17 support.

It enables you to more easily implement language servers by writing them in Go. GLSP contains:

1. all the message structures for easy serialization,
2. a handler for all client methods, and
3. a ready-to-run JSON-RPC 2.0 server supporting stdio, TCP, WebSockets, and Node.js IPC.

All you need to do, then, is provide the features for the language you want to support.

Protocol Versions

protocol_3_17 extends protocol_3_16 via type aliases for unchanged types and native definitions for 3.17 additions. Import only the version you need:

import protocol "github.com/bennypowers/glsp/protocol_3_17"

Types shared between versions are assignment-compatible, so handler functions inherited from 3.16 accept 3.17 values without casting.

Projects using GLSP:

• asimonim - Design token language server
• cem - Custom elements manifest language server

Minimal Example

package main

import (
	"github.com/bennypowers/glsp"
	protocol "github.com/bennypowers/glsp/protocol_3_17"
	"github.com/bennypowers/glsp/server"
	"github.com/tliron/commonlog"

	// Must include a backend implementation
	// See CommonLog for other options: https://github.com/tliron/commonlog
	_ "github.com/tliron/commonlog/simple"
)

const lsName = "my language"

var (
	version string = "0.0.1"
	handler protocol.Handler
)

func main() {
	// This increases logging verbosity (optional)
	commonlog.Configure(1, nil)

	handler = protocol.Handler{
		Initialize:  initialize,
		Initialized: initialized,
		Shutdown:    shutdown,
		SetTrace:    setTrace,
	}

	server := server.NewServer(&handler, lsName, false)

	server.RunStdio()
}

func initialize(context *glsp.Context, params *protocol.InitializeParams) (any, error) {
	capabilities := handler.CreateServerCapabilities()

	return protocol.InitializeResult{
		Capabilities: capabilities,
		ServerInfo: &protocol.InitializeResultServerInfo{
			Name:    lsName,
			Version: &version,
		},
	}, nil
}

func initialized(context *glsp.Context, params *protocol.InitializedParams) error {
	return nil
}

func shutdown(context *glsp.Context) error {
	protocol.SetTraceValue(protocol.TraceValueOff)
	return nil
}

func setTrace(context *glsp.Context, params *protocol.SetTraceParams) error {
	protocol.SetTraceValue(params.Value)
	return nil
}