Snail Language Support

The Snail Language Support aims to add language support for the snail programming language, developed by Assistant Professor Kevin Angstadt at St. Lawrence University.

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Features

Snail Language Support adds a number of features to the snail language

Static Error Checking

Snail Language Support provides static error checking of lexing and parsing errors. Runtime/Interpreter errors are currently not supported or checked.

Rudimentary autocomplete

Snail Language Support also provides basic autocomplete for common code structures, such as if statements, while loops, and variable definitions. To utilize this function, type a snippet 'trigger' (listed below) in a snail file, and press tab to select the appropriate autocomplete.

For a more detailed description of intended outputs, see snippets/snippets.json

Trigger	Content
if	if-else conditional
while	while loop
class	standard class definition
class-inherits	class that inherits from superclass definition
class M	Main class with main() method
class m	Main class with main() method
main	Main class with main() method
Main	Main class with main() method
main-inherits	Main class inheriting from superclass with main() method
Main-inherits	Main class inheriting from superclass with main() method
method-def	standard method definition
let	standard variable declaration
let-def	standard variable declaration and assignment

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Installation

Currently, Snail Language Support is not available on the online VS Code extension marketplace. To install, please follow the instructions below.

1. Ensure that the code command is installed and usable on your machine.

code -v

If this command gives you an error, visit the following pages to install the code onto your path. Note that exact steps will vary from machine to machine, so the following pages are meant to be a starting point.

• macOS VS Code setup instructions
• Windows VS Code setup instructions
• Linux VS Code setup instructions

2. Navigate to a directory where you like to keep miscellaneous download files and run the following commands.

# download vsix file
curl -Ok https://raw.githubusercontent.com/snail-language/snail-language-support/main/snail-language-support-1.0.0.vsix

# install the extension from .vsix file
code --install-extension snail-language-support-1.0.0.vsix

Note: if you'd rather, you can also choose to download the raw .vsix through the GitHub UI on our Snail Language Support GitHub page

Note: the code --install-extension command will handle placing relevant extension files in the right location for use inside of VS Code. We must just ensure that we run the code --install-extension command in a location that we have access to our .vsix file.

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Requirements

Snail Language Support requires an installation of snail of version 1.3.0 or greater. To check your version of snail, run the following command

# Check for snail version >1.3.0
snail -v 

If a snail interpreter is not found, or it has version <1.3.0, see installation instructions here.

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Extension Settings

There are a few notable settings provided in this extension that are worth configuring prior to using this extension.

• snailLanguageServer.snailPath: Absolute path to snail executable to use for Language Server. This is required for static error checking.
• snailLanguageServer.maxNumberOfProblems: The maxmimum number of problems our language server is allowed to produce when looking at a single file. In practice, Snail Language Support's current implementation of a language server is unable to produce more than one problem.
• snailLanguageServer.trace.server: Traces the communication between VS Code and the language server. Primarily for debugging purposes. off, message, or verbose

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Issues

If you encounter an issue with the Snail Langauge Support extension (bug, feature request, or other), please open an issue on our GitHub Repository.

Known Issues

There are a few known issues/bugs that you may encounter that are under plans for future work.

• When changing the snailLanguageServer.snailPath setting, you must developer reload your VS Code window in order to allow the language server to restart and the change to take effect.

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Development

There are a number of things that are helpful to know when starting development on this extension. They are noted below.

Testing locally

Currently, we have no automated testing process or testing scripts. As such, testing is limited to local testing and manually verifying that previous functionality still exists.

Packaging Extension for distribution

As Snail Language Support is not available on the VS Code extension marketplace, we release a new downoadable packaged extension .vsix file with each change. We use the Visual Studio Code Extensions command line tool vsce to do this. To generate this packaged extension, follow the instructions below.

NOTE: the online vsce documentation includes directions to publish the extension to the online marketplace. Be sure to read online documentation carefully to avoid publishing to the online marketplace.

# Ensure that you have the vsce tool installed
npm install -g @vscode/vsce

# Navigate to the snail-language-support directory
cd path/to/snail-language-support

# package the extension src files
vsce package

This should generate a snail-language-support-1.x.x.vsix file. Include this file when you push any changes to the Snail Language Support repository.

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Release Notes

1.0.0

Initial release of Snail Language Support