Language Server Protocol and Implementation: Supporting Language-Smart Editing and Programming Tools

✍ Scribed by Nadeeshaan Gunasinghe, Nipuna Marcus

• Publisher: Apress
• Year: 2021
• Tongue: English
• Leaves: 250
• Category: Library

✦ Synopsis

Understand the important aspects of implementing a production-grade language server in support of language-smart tools such as code editors and other programming utilities. This book shows you how to create a single implementation of a language server that can be used by multiple tools, enabling you to do the job once in a way that can be shared and reused.
This book covers the language server protocol used for communication between programming tools and your language server. The book also provides an in-depth understanding of the design, implementation, and user experience aspects which should be considered when implementing a language server. The book walks you through an example language server implementation to illustrate the basic concepts, then goes on to cover advanced aspects of language server use such as progress reporting, launchers, and extension points.
User experience is an important aspect of language server implementation and different tooling vendors strive to provide their own unique user experiences. This book explains how the protocol features can be leveraged to address the unique developer experience provided by different tooling vendors. The book also shows how to enhance the smoothness of the editing experience by orchestrating multiple features together.

What You Will Learn

• Implement a language server from scratch
• Understand language server protocol and its data models
• Leverage the protocol while preserving the unique user experience of different editors
• Extend the protocol to support more than its standard capabilities
• Run a language server on top of launchers such as standard I/O and TCP socket
• Seamlessly incorporate language semantics into your protocol features

Who This Book Is For

Developers focused on and passionate about implementing language development tools such as plug-ins and extensions for interactive development environments (IDEs) or other tools that rely upon parsing of language statements and commands, and developers who need an in-depth understanding of the language server protocol as well as how to use the language server protocol to develop extensible language services

✦ Table of Contents

Table of Contents
About the Authors
About the Technical Reviewer
Acknowledgments
Introduction
Chapter 1: Developer Tools and Language Services
Early Programmable Computers
Code Forms and Punched Cards
Text Editors vs. Source Code Editors
Why IDEs
Language Intelligence
Summary
Chapter 2: Understanding the Language Server Protocol
Understanding JSON-RPC
Request Object
jsonrpc
method
params
id
Notification
Response Object
jsonrpc
result
error
id
Error Object
code
message
data
Batch
Understanding the Base Protocol
Header Part
Content Part
Communication Model
General Messages
Outline Placeholder
window
telemetry
workspace
textDocument
Summary
Chapter 3: Implementing a Language Server
Tools and Dependencies
Building the Project
Compatibility with Ballerina
Debugging the Client and the Server
Understanding the Main Components
Server API
Server Core
Client Implementation
Summary
Chapter 4: General Messages
General Messages
Initialize
Generating the InitializeResult
Initialized
Shutdown
Exit
Window Operations
ShowMessage
ShowMessageRequest
Generating the Request
ShowDocument
Generating the Request
LogMessage
Progress/Create
Progress/Cancel
Summary
Chapter 5: Text Synchronization
General Capabilities
didOpen
Indexing and Project Initialization
didChange
willSave
willSaveWaitUntil
didSave
didClose
Summary
Chapter 6: Diagnostics, Smart Editing, and Documentation
Diagnostics
Initialization and Capabilities
Publishing the Diagnostics
Completion
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the Completions
Text Insertion
Documentation and Additional Information
Sorting and Filtering
Completion Resolve
Signature Help
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the Signature Help
Hover
Initialization and Capabilities
Client Capabilities
Generating the Hover
Summary
Chapter 7: Refactoring and Code Fixes
Rename
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the Workspace Edit
Prepare Rename
Formatting
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the Formatting TextEdits
Range Formatting
Initialization and Capabilities
Generating the Range Formatting TextEdits
On Type Formatting
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the On Type Formatting TextEdits
Code Actions
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the CodeAction
Request Parameters
Generating the Response
Code Actions Resolve
CodeLens
Initialization and Capabilities
Client Capabilities
Server Capabilities
Generating the Response
CodeLens Resolve
CodeLens Refresh
Summary
Chapter 8: Code Navigation and Navigation Helpers
Reference
Client Capabilities
Server Capabilities
Generating the Response
Definition
Client Capabilities
Server Capabilities
Generating the Response
Type Definition
Client Capabilities
Server Capabilities
Generating the Response
Implementation
Client Capabilities
Server Capabilities
Generating the Response
Declaration
Client Capabilities
Server Capabilities
Generating the Response
Document Symbol
Client Capabilities
Server Capabilities
Generating the Response
Using SymbolInformation
Using DocumentSymbol
Document Highlight
Client Capabilities
Server Capabilities
Generating the Response
Document Link
Client Capabilities
Server Capabilities
Generating the Response
Document Link Resolve
Summary
Chapter 9: Presentation and Selection
Semantic Tokens
Client Capabilities
Server Capabilities
Generating the Response
Semantic Tokens for Whole Document – full
Semantic Tokens for Whole Document – full/delta
Semantic Tokens for a Range – range
Encoding and Decoding a Token
Document Color
Client Capabilities
Server Capabilities
Generating the Response
Color Presentation
Generating the Response
Folding Range
Client Capabilities
Server Capabilities
Generating the Response
Selection Range
Client Capabilities
Server Capabilities
Generating the Response
Linked Editing Range
Client Capabilities
Server Capabilities
Generating the Response
Prepare Call Hierarchy
Client Capabilities
Server Capabilities
Generating the Response
Call Hierarchy Incoming
Generating the Response
Call Hierarchy Outgoing
Generating the Response
Summary
Chapter 10: Workspace Operations
Workspace Folders
Client Capabilities
Server Capabilities
Sending the Request
Workspace Folders Change Notification
Client Capabilities
Server Capabilities
Processing the Notification
Notification of Configuration Change
Client Capabilities
Processing the Notification
Configuration
Client Capabilities
Generating the Request
Watched Files Change Notification
Client Capabilities
Registration Options
Processing the Notification
Workspace Symbol
Client Capabilities
Server Capabilities and Registration Options
Generating the Response
Execute Command
Client Capabilities
Server Capabilities
Executing the Command
Apply Edit
Client Capabilities
Sending the Request
Will Create Files
Client Capabilities
Registration Options
Generating the Response
Did Create Files
Client Capabilities
Server Capabilities
Handling the Notification
Will Rename Files
Client Capabilities
Server Capabilities
Generating the Response
Did Rename Files
Client Capabilities
Server Capabilities
Handling the Notification
Will Delete Files
Client Capabilities
Server Capabilities
Generating the Response
Deleted Files Notification
Client Capabilities
Server Capabilities
Handling the Notification
Summary
Chapter 11: Advanced Concepts
Work Done Progress
Begin Progress
Report Progress
End Progress
Implementing the Server-Initiated Progress
Partial Result Support
Working with Launchers
Extension Points
Implementing and Extending Protocol Services
Request Parameters
Response Parameters
Implementing the Service
Supporting Multiple Languages
Dynamic Registration of Capabilities
Implementing a Delegator Mechanism
Summary
Index