<dfn>Functional</dfn> is a library for functional programming
in JavaScript. It defines the standard higher-order functions
such as <code>map</code>, <code>reduce</code> (aka
<code>foldl</code>), and <code>select</code> (aka
<code>filter</code>). It also defines functions such as
<code>curry</code>, <code>rcurry</code>, and
<code>partial</code> for partial function application; and
<code>compose</code>, <code>guard</code>, and <code>until</code>
for <a href="http://en.wikipedia.org/wiki/Function-level_programming">function-level
programming</a>. And all these functions accept strings, such
as <code>'x -> x+1'</code>, <code>'x+1'</code>, or
<code>'+1'</code> as synonyms for the more verbose
<code>function(x) {return x+1}</code>.
