Mini string encoders/decoders for the Web
Here's a list of tiny functions whose goal is to convert any Unicode string in 28 different formats used on the Web, and do the reverse operation.
An online converter using those functions can be found here: http://xem.github.io/escape
Please contribute in the comments (or by pull request) if you have a feature idea or a code-golf improvement to make or a bug to solve.
NB: to be as short as possible, all those functions assume a valid input and convert all chars (including ASCII chars and non-ASCII chars that don't really need to be converted in some cases).