u

U U extends Ruby’s Unicode support. It provides a string class called U::String with an interface that mimics that of the String class in Ruby 2.0, but that can also be used from both Ruby 1.8. This interface also has more complete Unicode support and never modifies the receiver. Thus, a U::String is an immutable value object. U comes with complete and very accurate documentation¹. The documentation can realistically also be used as a reference to the Ruby String API and may actually be preferable, as it’s a lot more explicit and complete than the documentation that comes with Ruby. ¹ See http://disu.se/software/u-1.0/api/ § Installation Install u with % gem install u § Usage Usage is basically the following: require 'u-1.0' a = 'äbc' a.upcase # ⇒ 'äBC' a.u.upcase # ⇒ 'ÄBC' That is, you require the library, then you invoke #u on a String. This’ll give you a U::String that has much better Unicode support than a normal String. It’s important to note that U only uses UTF-8, which means that #u will try to #encode the String as such. This shouldn’t be an issue in most cases, as UTF-8 is now more or less the universal encoding – and rightfully so. As U::Strings¹ are immutable value objects, there’s also a U::Buffer² available for building U::Strings efficiently. See the API³ for more complete usage information. The following sections will only cover the extensions and differences that U::String exhibit from Ruby’s built-in String class. ¹ See http://disu.se/software/u-1.0/api/U/String/ ² See http://disu.se/software/u-1.0/api/U/Buffer/ ³ See http://disu.se/software/u-1.0/api/ § Unicode Properties There are quite a few property-checking interrogators that let you check if all characters in a U::String have the given Unicode property: • #alnum?¹ • #alpha?² • #assigned?³ • #case_ignorable?⁴ • #cased?⁵ • #c...