Biff.core: system composition for Clojure web apps

The author introduces biff.core, the inaugural release from a significant overhaul of the Biff web framework. Positioned as the foundational "glue" for Biff 2.x, this library focuses on streamlining how web applications are composed from various modules and components.

• Simplifying System Composition: The primary goal of biff.core is to reduce the boilerplate previously required to combine application modules into a singular "system" map. This structure now enables libraries to integrate more seamlessly by simply adding a module without extensive manual configuration.
• Introducing Init Functions: The core innovation is "init functions." These functions accept a collection of modules and return a map ready to be merged directly into the application's system map, simplifying the overall project structure.
• Addressing Hot-Reloading Challenges: A significant design challenge was maintaining the late-binding benefits essential for hot-reloading in development. The solution involves init functions taking a var of the modules vector, and critical system map keys becoming functions that dereference this var and utilize memoization for efficient updates without server restarts.
• Philosophy on Component Management: The author intentionally avoids implementing a complex dependency management system for components, arguing that manual ordering is clearer and sufficient for most projects, maintaining simplicity and ease of understanding.

Ultimately, biff.core offers Clojure developers a more elegant and less verbose way to structure web applications, providing practical solutions for module integration and hot-reloading while adhering to a pragmatic design philosophy.