A good friend of mine convinced me about the benefits of Reactive Programming not that long ago. It almost feels wrong not to write Functional Reactive Programming -- the functional methodology lends itself magnificently to compliment reactive programming. So I decided to learn this stuff.

Knowing myself, I soon realized I would only ever get in the mindset if I had to solve some actual problems using the techniques. Having written JavaScript for the past few years, I could have just gone for RxJS. But again, I knew myself and felt it would give me way too much room for "going against the grain". I needed something that would enforce me to solve everything in a functional manner. This is where Elm comes in.

• Haskell-inspired language that compiles into HTML5
• immutable data
• strong types
• functional
• reactive

• all functions are pure
• no way to cause side-effects
• type annotations clarify the goal
• there are no loops
• mind-twister: Signal.foldp

• a signal is a function of time
  • for each moment, there exists a pure value of a signal
• Signal.foldp reduces the value in the same sense as List.foldl -> each state of the interactive program is explicitly derived from all things that have happened in the past

• FP is often terse and readable
• reactive pattern makes input and output explicit
• no worries about weird states