嗯，有时间看看，有什么名堂在里面
是这个，你可以download source code, 是open source的
http://documentcloud.github.com/underscore/
Underscore.js
Underscore is a utility-belt library for JavaScript that provides a lot of the functional programming support that you would expect in
Prototype.js (or
Ruby), but without extending any of the built-in JavaScript objects. It's the tie to go along with
jQuery's tux.
Underscore provides 60-odd functions that support both the usual functional suspects:
map,
select,
invoke — as well as more specialized helpers: function binding, javascript templating, deep equality testing, and so on. It delegates to built-in functions, if present, so modern browsers will use the native implementations of
forEach,
map,
reduce,
filter,
every,
some and
indexOf.
A complete
Test & Benchmark Suite is included for your perusal.
You may also read through the
annotated source code.
The project is
hosted on GitHub. You can report bugs and discuss features on the
issues page, on Freenode in the <tt>#documentcloud</tt> channel, or send tweets to
@documentcloud.
Underscore is an open-source component of DocumentCloud.
