Effect Beginner/Intermediate Workshop By Ethan Niser

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USEFUL LINKS

• Effect API Docs
• Effect Docs
• Effect Source
• Effect Discord

REQUIREMENTS:

Choose your runtime:

• Bun (recommended)
• Node >= 23.6 will allow you to run TypeScript without transpiling
• Node < 23.6 with a typescript transpiler (like ts-node or tsx)

https://nodejs.org/en

npm i -g tsx

I'm using bun just because its over twice as fast to run typescript than with tsx or ts-node If you want to also use bun you can install it at https://bun.sh/docs/installation

Install JS Dependecies

npm i
yarn i
pnpm i
bun i

An editor that supports LSP

Hovering to see types, autocompletion, and go-to-definition are gonna be pretty useful. I'll be using VSCode, but you can use any editor that supports LSP.

How this project is broken up

Slides

The slides are available online at https://effect-workshop-slides.vercel.app But, if you wish to run the slides locally:

cd slides
bun run dev

All of the content is in the src folder

Each part has its own folder. Within those folders you find these folders:

snippets

This contains typescript files that have code examples and comment explanations for individual concepts. I will go through these files in the workshop. Free free to follow along and read the comments.

exercises

This contains typescript files that define some practice exercises for individual concepts. They define test cases that you can check by just running the file.

Solutions are located in the solutions folder

project

For parts 2 and 3, we will be rewriting a non-effect application to effect. The project folder contains the non-effect application, and is where if you want to follow along, you can modify the code to use effect.

AFTER_THE_WORKSHOP.md

To reinforce your learning, I've provided some ideas for how to expand each project when you get home. Try them out on your own, and if you need help feel free to @ me in the Effect discord- I'd love to see how people approach each problem.

breakpoints

For parts 2 & 3, 'breakpoints' defines each of the steps we will take to refactor the non-effect application to effect. Each file is a folder. All changes between steps are described in the changes.md file.

If you get lost, you can always copy whatever 'breakpoint' you are on to the project folder and continue from there.

pad.ts

Stands for 'scratchpad'. Pretty useful for just trying out some code that doesn't necessarily belong anywhere.

bun run pad

Running Files

Every file is prefixed with a number. I have defined a bun of scripts so you don't have to type out the whole file name / path.

They follow this pattern:

part = 1 | 2 | 3 | 4
section = s (snippets) | e (exercises) | p (project) | b (breakpoints)
fileOrFolderNumber = (if folder will run index.ts)

bun run part-section-fileOrFolderNumber

For example, to run the first snippet in part 1:

bun run 1-s-1

To run the first exercise in part 2:

bun run 2-e-1

To run the part 3 project:

bun run 3-p

Cheat Sheet

For quick reference or for review feel free to read CHEATSHEET.md

VSCode Snippets

{
  "Gen Function $": {
    "prefix": "gg",
    "body": ["function* () {\n\t$0\n}"],
    "description": "Generator function"
  },
  "Gen Function $ (wrapped)": {
    "prefix": "egg",
    "body": ["Effect.gen(function* () {\n\t$0\n})"],
    "description": "Effect.gen with Generator function"
  },
  "Gen Yield $": {
    "prefix": "yy",
    "body": ["yield* $0"],
    "description": "Yield generator calling"
  },
  "Gen Yield $ (const)": {
    "prefix": "cyy",
    "body": ["const $1 = yield* $0"],
    "description": "Yield generator calling and assign to const"
  }
}