A analysis server for the smart contract language Scilla following the language server protocol.
https://czarly.github.io/scilla-language-server/
The implementation is based on Xtext which is a Eclipse project for building tool support for DSL. Therefore running the language server and the Visual Studio Code plugin requires Java to be installed on the machine. The planned features include what is provided by the Xtext language server implementation:
- Syntax Coloring
- Error Checking
- Auto-Completion
- Formatting
- Hover Information
- Mark Occurences
- Go To Declaration
- Rename Refactoring
- Toggle Comments
- Outline / Structure View
- Quick Fix Proposals
- Find References
Prerequisites: Docker and Visual Studio Code need to be installed
check out the code and in the root folder run the following command in a terminal
docker run -it --rm --name build-scilla-language-server -v "$(pwd)":/usr/src/scilla-base -w /usr/src/scilla-base maven:3.6-jdk-8 mvn clean package
cd org.butterflylabs.zilliqa.xtext.ide/vscode
npm install vsce
npm install -g vsce
npm install
vsce package
code --install-extension scilla-vscode-extension-1.0.0.vsixThis will compile and install the Visual Studio Code extension contained in this repository to your local installation.
It will be associated with *.scillla files and provide basic functionality.
The project contains several Eclipse projects based on Maven which can be imported into a Eclipse workspace.
Please refer to the Xtext documentation for further guidance. The Xtext modules for Eclipse have to be installed.
The extension loads and parses the source code using a grammar. It's generating recommendations for auto-completition based on context and can import namespaces whose exports are available to the auto-completition and validator as well.
The main limitation as of now is that types are not resolved.
The more refined parts of the protocol didn't get much attention as the basics had to be carved out. Parsing and Scoping works pretty well already and the language server speaks its protocol.
Next steps:
- Formatting
- Outline View
- Renaming
- Limit the autocomplete suggestions to symbols that can be referenced
- Integrating Xsemantics for type checking including classifying variables as functions or values
- Writing tests
This provided the language server will not give the cosy feeling that I would like it to, but the further changes are more of a cosmetic nature, like proper naming of nodes in the outline view or better tooltips with additional information to elements.
I took on this project as part of the Zilliqa ecosystem grant. I intended to work on parts that where more related to my actual coding experience, but ended up learning something new and finally work with Java again after 6 years of JavaScript.
Turns out the parser is complicated but the easiest part. All the auto magic impresses at first sight but quickly develops into a bottleneck as it has to be fully understood to be adapted in the way you need it to work. Through the nature of a the task of specifying a new language it's natural for Xtext tools to favor you to adapt your DSL instead of the default plumbing, because you can. But they also provide structure and insights that gives a handle to approach the topic in a orderly manner if you have to.
After finishing this project I will be pretty good at parsing, scoping, linking, formatting and probably more.
Maybe next i can build a compiler. Xtext provides a generator to produce any kind of text file from the user defined models. It's straight forward to produce Java source code that can be compiled and executed. But thats probably more useful to generate templates.
After all through the approach of using a framework to produce a editor component for a framework to build developer tools it might be possible to come up with a integrated development environment for Zilliqa based on Eclipse. I'm wary of using the word straight forward here.
As I understand it, Eclipse has a browser based workspace solution that can be hosted using Docker and extended with standard Eclipse plugins. This might be a way to provide hosted adhoc development environments for teaching programming for Zilliqa.