Programming framework of musicblocks-v4

This repository contains the source code for the programming framework of the new Music Blocks (v4) application.

Architecture

Syntax Representation

Element API represents syntax elements — the atomic constructs for building programs. There are 2 kinds of syntax elements:
- Arguments which return values. These are of 2 types:
  - Data which return a value inherently and without operating on other provided values
  - Expression which return a value after operating on other provided values
- Instructions which perform a task. These are of 2 types:
  - Statements perform a single task
  - Blocks encapsulate statements and generally set some states or control the flow to them
Specification maintains a table of actual syntax elements which can be used to build programs.
Warehouse maintains a table of instances of syntax elements registered in the specification. It can also generate statistics about the instances.
Tree represents the syntax tree (abstract syntax tree or AST) by maintaining interconnections between syntax elements.

Execution

Symbol Table maintains tables of dynamic variables and states which the syntax elements can use during execution.
Parser parses the syntax tree in a postorder sequence, and maintains call frame stacks and the program counter.
Interpreter fetches elements from the parser and executes them.
Scheduler manages the concurrent orchestration of the execution process.

Monitor proxies information about the execution states and statictics.

There are 2 special constructs: Process and Routine. These are special block elements. Routines encapsulate instructions that can be executed by multiple processes. Processes encapsulate independent set of instructions, and multiple processes can run concurrently.

There is an additional terminology called crumbs which are sets of connected syntax elements not part of any process or routine.

Plugins

The core framework doesn't define any special syntax elements other than process and routine. All concrete syntax elements are plugins which extend the syntax element API and are registered in the syntax specification.

A set of programming specific syntax elements are bundled as a library, which use nothing beyond the set of constructs exposed by the syntax element API.

Tech Stack

This core of Music Blocks v4 uses TypeScript 4. In addition, Jest shall be used for testing.

Contributing

Programmers, please follow these general guidelines for contributions.

New Contributors

Use the discussions tab at the top of the repository to:

Ask questions you’re wondering about.
Share ideas.
Engage with other community members.

Feel free. But, please don't spam :p.

Keep in Mind

Your contributions need not necessarily have to address any discovered issue. If you encounter any, feel free to add a fix through a PR, or create a new issue ticket.
Use labels on your issues and PRs.
Do not spam with lots of PRs with little changes.
If you are addressing a bulk change, divide your commits across multiple PRs, and send them one at a time. The fewer the number of files addressed per PR, the better.
Communicate effectively. Go straight to the point. You don't need to address anyone using 'sir'. Don't write unnecessary comments; don't be over-apologetic. There is no superiority hierarchy. Every single contribution is welcome, as long as it doesn't spam or distract the flow.
Write useful, brief commit messages. Add commit descriptions if necessary. PR name should speak about what it is addressing and not the issue. In case a PR fixes an issue, use fixes #ticketno or closes #ticketno in the PR's comment. Briefly explain what your PR is doing.
Always test your changes extensively before creating a PR. There's no sense in merging broken code. If a PR is a work in progress (WIP), convert it to draft. It'll let the maintainers know it isn't ready for merging.
Read and revise the concepts about programming constructs you're dealing with. You must be clear about the behavior of the language or compiler/transpiler. See JavaScript docs and TypeScript docs.
If you have a question, do a web search first. If you don't find any satisfactory answer, then ask it in a comment. If it is a general question about Music Blocks, please use the new discussions tab on top the the repository, or the Sugar-dev Devel <sugar-devel@lists.sugarlabs.org> mailing list. Don't ask silly questions (unless you don't know it is silly ;p) before searching it on the web.

Code Quality Notes

Sticking to TypeScript conventions, use camelCase for filenames (PascalCase for class files), CAPITALCASE for constants, camelCase for identifiers, and PascalCase for classes. Linting has been strictly configured. A super-linter is configured to lint check the files on a pull request. In fact, the TypeScript watcher or build will throw errors/warnings if there are linting problems. This has been done to maintain code quality.
If a PR is addressing an issue, prefix the branch name with the issue number. For example, say a PR is addressing issue 100, a branch name could be 100-patch-foobar.
Meaningfully separate code across commits. Don't create arbitrary commits. In case it gets dirty, please do an interactive rebase with squash and reword to improve.
Follow conventional commit messages specification to help issue tracking. More often than not, take time to add meaningful commit descriptions. However, add specificity by mentioning the component; prefer mycomponent: [feat] Add button over feat: Add button, mycomponent: [fix] Use try-catch over fix: Use try-catch.
At any point, when new components are created or existing components are modified, unit tests (passing) reflecting the changes need to be part of the PR before being reviewed.
Two workflows — a Continuous Integration (CI) and a Linter (Super Linter), have been configured. Each PR must pass the checks before being reviewed.
For any new functions/methods or classes, add extensive TSDoc documentation.
Each PR needs to have supporting unit tests covering all (or as much practical) use cases to qualify for review. In case testing is done via some non-standard method, adequate description of the method/s need/s to be specified in the PR body.

Please note there is no need to ask permission to work on an issue. You should check for pull requests linked to an issue you are addressing; if there are none, then assume nobody has done anything. Begin to fix the problem, test, make your commits, push your commits, then make a pull request. Mention an issue number in the pull request, but not the commit message. These practices allow the competition of ideas (Sugar Labs is a meritocracy).

Setup Development Environment

Without Docker

This is a TypeScript project. You'll need the following installed on your development machine:

Node.js
Yarn
tsc (TypeScript Compiler) to manually compile .ts files.
ts-node (Node.js executable for TypeScript) to manually execute .ts scripts directly.

Installing Node.js will install NPM (Node.js Package Manager) by default. Use it to install Yarn using

npm install -g yarn

Once Yarn is installed, to install the above, run

yarn global add typescript
yarn global add ts-node

Note: Users on Linux and MacOS are required to add a sudo before these commands.

Check installation using

node -v && yarn -v && tsc -v && ts-node -v

Output should look like

v14.17.0
6.14.13
Version 4.3.2
v10.0.0

With Docker

This project development tools have been containerized using docker. Therefore, to use an execution sandbox, it requires docker to be installed on the development machine.

Setup docker.
- For Linux, install Docker Engine. You'll also need to install Docker Compose.
- For Windows or Mac, install Docker Desktop.
Open a teminal and navigate to working directory (where the source code will reside).
Git Clone (additional installation of Git required on Windows) this repository using
```
git clone https://github.com/sugarlabs/musicblocks-v4-lib.git
```
Build docker image and launch docker network.

Note: A built initial development image has been published to Sugar Labs GitHub Container Registry (GHCR), which can be pulled directly, so you don't have to build it again. Pull using
```
docker pull ghcr.io/sugarlabs/musicblocks:initial
```
Nagivate inside the project directory and launch the docker network using
```
docker-compose up -d
```
or (for Docker v1.28 and above)
```
docker compose up -d
```
If you haven't pulled the image from the GitHub Container Registry (GHCR), it'll first build the image using the Dockerfile, then launch the docker network. If an image already exists locally, it'll not be rebuilt. To force a rebuild from the Dockerfile before launching the docker network, add the --build flag.
In another terminal, run
```
docker attach musicblocks
```
The Linux Debian 10.7 (buster) shell in the docker container named musicblocks is spawned and standard input/output is connected to the terminal.

Node (Node.js Runtime), yarn (Node Package Manager), tsc (TypeScript Compiler), and ts-node (Node executable for TypeScript) should be installed. Check using
```
node --version && yarn --version && tsc --version && ts-node --version
```
Output should look like
```
v14.16.1
7.9.0
Version 4.2.4
v9.1.1
```
To shut down the docker network, run (in the terminal where you ran docker-compose up -d or docker compose up -d)
```
docker-compose down
```
or (for Docker v1.28 and above)
```
docker compose down
```
To install all the dependencies (in package.json), run
```
yarn install --frozen-lockfile
```
Miscellaneous commands.
- To launch the Node.js runtime, run
```
node
```
- To run a JavaScript file, say file.js, run
```
node file.js
```
- To transpile a TypeScipt file, say file.ts, to JavaScript, run
```
tsc file.ts
```
  This transpilation produces file.js.
- To run a TypeScript file directly, say file.ts, run
```
ts-node file.ts
```
Configured scripts.
- For testing, run
```
yarn run test
```
  To run a specific path
```
yarn run test -- "test/path"
```
  To run in watch mode
```
yarn run test -- "test/path" --watch
```
- For generating a production build, run
```
yarn run build
```
- For checking linting problems
```
yarn run lint
```
  To autofix fixable problems
```
yarn run lint -- --fix
```
Note: If you're running using Docker Desktop on Windows, you might experience longer execution times for these scripts. This happens due to cross-file-system communication. Duration varies across machines; duration primarily depends on hard drive read/write speed.

Editor

All code is just plain text, so it doesn't really matter what you use to edit them. However, using modern, feature-rich IDEs/text-editors like Atom, Brackets, WebStorm, Sublime Text, Visual Studio Code, etc. makes life way easier. These come with a directory-tree explorer, and an integrated terminal, at the very least, while having support for plugins/extensions to expand their functionality.

Some (non-exhaustive) benefits of using these are syntax highlighting, warning/error annotations, formatting, auto-refactoring, tons of customizable keyboard shortcuts, etc.

Visual Studio Code (VSCode) is currently the most-popular code editor for reasons like being lightweight, cleaner, large marketplace of extensions, integrated Source Control features, debugger, remote explorer support, Regular Expression (regular expression) based find/replace, etc.

In fact, a workspace configuration file for vscode.vscode/settings.json has already been added. Recommended extensions for this project are Babel JavaScript, Docker, ESLint, Git Graph, GitLens, markdownlint, Prettier, SCSS IntelliSense, and SVG.

All that, however, shouldn't necessarily stop you from using Emacs, Nano, or Vim, if that's your poison :D. Happy coding!

sugarlabs/musicblocks-v4-lib