clojure_lessons_learned.md

layout	title	date	comments	categories
post	Clojure Lesson Learned	2013-07-04 18:45	true

background

• new to clojure
• working with it for about 2 Month now
• some java interop with (Parallel Colt, Mahout)
• simple data analysis incanter

likes

• immutable data structures
• awesome that they are persistent

<iframe width="420" height="315" src="//www.youtube.com/embed/wASCH_gPnDw" frameborder="0" allowfullscreen></iframe> - syntax flexability - REPL

dislike

• debugging :(
• error messages
• suspission: partial
• JVM startuptime xD

lessons learned

• thinking with immutable data structures in very different. You will need some time.
• don't overuse use
  • use require instead
• inject state via function arguments, done this one right, see Stuart Sierrra: Clojure in the Large
• don't overuse ->> let is ok in many cases
• Write test!! despite the REPL (was a bit to lazy in that regard)
  • The default Test framework seams to be midje
  • but I liked my classical TDD/BDD DSL so I used speclj
• prallel pmap does the trick in many cases
  • start at top level
• want to experiment more with reducers!
• pre and post assertions are a blessing and so easy to use
• you need only a hand full of vars. In many cases none at all. Ask Stuart ;)
• they introduce global state, so use with utmost caution
• I can't remember the syntax for optional parameters!

vim and clojure

• vim fireplace REPL more stable that sublime REPL
• Sublime Repl nicer (because it shows the last call)
• vim fireplace hace invaluable :Doc and :Souce commands!
• no ctags support for clojure but lisp works fine
• rainbow parentecies
• y%and d% are big time and brain power savers