Clojure deps.edn & Your First Script — Phase 1 Finale | Episode 6

Time to move from the REPL to a real project. In this episode we create a project with deps.edn, write a namespace with a -main entry point, and run it from the command line with clj -M -m. This is the final episode of Phase 1: REPL and First Values. By the end, you will have a project that takes command-line arguments and greets each one. Student code: https://github.com/GoCelesteAI/clojure-first-script Every keystroke is shown on screen with generous pauses so you can follow along at your own pace. What You'll Learn: - deps.edn as the project config file - :paths tells Clojure where source files live - Namespace-to-path mapping (hello.core becomes src/hello/core.clj) - The -main function as the entry point - and-args for variadic command-line arguments - clj -M -m hello.core to run a namespace - doseq to loop through arguments - Switching files in Neovim with :e Project structure: my-app/ deps.edn {:paths ["src"]} src/hello/core.clj (ns hello.core) + (defn -main ...) Timestamps: 0:00 - Intro 0:12 - Preview: from REPL to project 0:32 - Create project directories 0:44 - Write deps.edn 1:00 - Write src/hello/core.clj 1:13 - Namespace declaration 1:23 - greet helper function 1:38 - The -main entry point 2:18 - First run: clj -M -m hello.core (no args) 2:50 - Output explained 3:14 - Second run with Alice and Bob 3:48 - Output explained (with args) 4:30 - Review deps.edn and core.clj 4:47 - Recap 5:15 - What's next — Phase 2 begins Key Takeaways: 1. deps.edn is the only config file you need. {:paths ["src"]} tells Clojure where source lives. 2. -main is the entry point. The dash is part of the name. and-args captures command-line input. 3. Namespace maps to file path: dots become slashes, hyphens become underscores in filenames. 4. Phase 1 is complete! You know the REPL, syntax, values, functions, conditionals, and project structure. Series Roadmap: - Episodes 1-6: REPL and first values (COMPLETE) - Episodes 7-13: Collections and sequences - Episodes 14-19: Functional core - Episodes 20-24: Namespaces, projects, testing - Episodes 25-30: State and concurrency - Episodes 31-35: Data modeling - Episodes 36-38: Macros - Episodes 39-41: Interop, Babashka, uberjars - Episodes 42-45: Capstone — web app deployment Next up — Phase 2 begins with Episode 7: Vectors. Taught by CelesteAI. Like and subscribe for more Clojure tutorials!