Very basic Coffeescript pattern matching

gistfile1.coffee

class Message

class Greeting extends Message
class Shout extends Message
class Farewell extends Message

# Curry for reusing the match
match = (patterns...) -> (val) ->
  for pat in patterns
    if val instanceof pat[0] then return pat[1](val)

matcher = match(
  [Greeting, -> console.log('hello!')]
  [Shout, -> console.log('*SHOUTS*')]
  [Message, (val) ->
    for i in [1..5]
      console.log('match not found for value ', val)
  ]
)

matcher(new Greeting)
matcher(new Shout)
matcher(new Farewell)

# >hello!
# >*SHOUTS*
# >match not found for value  {}
# >match not found for value  {}
# >match not found for value  {}
# >match not found for value  {}
# >match not found for value  {}