{Readable, Transform} = require("stream")

class ToUpper extends Transform

  _transform: (data, enc, next) ->
    @push data.toString().toUpperCase()
    next()


# a simple transform stream
tx = new ToUpper

# a simple source stream
rs = new Readable
rs.push 'the quick brown fox jumps over the lazy dog!\n'
rs.push null 

rs.pipe(tx)
  .pipe(process.stdout)   # THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG!