Implementing Infinite Data Structure in JavaScript.

== 11/26 ==
 * {{{naturalSequence().filter(limit(n)).reduce(sum)}}}
  * {{{sum(a, b) := a + b}}}
  * {{{limit(n)(a) := (n >= a)}}}
  * {{{.reduce(f(a, b)) := f(seq[:last-1].reduce(f), seq[last])}}}
  * {{{filter(f(a)) := for each a in seq, sequence of a which f(a) is true.}}}