CoffeeScript: tiny DSL for switch-like function based control flow

switchx.coffee

switchx = (value, fns...) -> return ret for fn in fns when ret=fn value
whenx   = (pred, fn) -> (val) -> (fn val) or true if pred val
defaultx = (fn) -> (val) -> fn val



# example
jump    = (p) -> p.takeEnergy JUMP_ENERGY
canJump = (p) -> p.getEnergy() > JUMP_ENERGY
# ...
switchx player,
  whenx canJump, jump
  whenx hasWater, compose drink, jump
  defaultx -> throw new Exception 'Cant jump!'