A solution to /r/dailyprogrammer's 153rd Easy challenge using only lambdas, essentially.

less_cryptic_153_easy.rb

factorial = -> n {
  n < 2 ? 1 : n * factorial[n - 1]
}

size = -> ary {
  sz = 0
  (cut = -> {
    sz += 1
    (ary = ary[1..-1]) == [] ? sz : cut[]
  })[]
}

map = -> ary, fn {
  sz = size[ary]
  i = 0
  ret = []
  (mapper = -> {
    ary[i] = fn[ary[i]]
    (i += 1) == sz ? ary : mapper[]
  })[]
}

triangle = -> n {
  map[[*0..n], -> x { factorial[n] / (factorial[x] * factorial[n - x]) }]
}

each = -> ary, fn {
  sz = size[ary]
  i = 0
  (eacher = -> {
    fn[ary[i]]
    (i += 1) == sz ? ary : eacher[]
  })[]
}

with_index = -> ary {
  sz = size[ary]
  i = 0
  ret = []
  (zipper = -> {
    ret << [ary[i], i]
    (i += 1) == sz ? ret : zipper[]
  })[]
}

n = 14
each[with_index[triangle[n - 1]], -> x { puts map[triangle[x[1]], -> y { y * x[0] }] * ' ' }]