Library for converting between native strings (assuming utf-16) and utf-8 encoded Uint8Arrays. Surrogate pairs are correctly handled and an effort has been made to ensure that invalid data is detected immediately.
No dependencies though you may wish to include a workaround for browsers that do not support typed arrays.
No compilation neccessary just copy utf8.js into your source tree. The file should work as a commonjs or AMD module as well as just inline.
To convert from a string literal or object to utf-8 simply call:
utf8.encode(string);
This function returns a Uint8Array based on a newly allocated ArrayBuffer sized to exactly fit the string.
Allocating and copying to this buffer takes less than five percent of the execution time of the function on my stem in both firefox and chrome.
In the event that the string is not valid utf-16, utf8.encode should throw an Error object with a hopefully reasonably helpfull message.
The reverse operation is:
utf8.decode(utf8_uint8_array, options)
The options argument is not required.
At the moment the only field that is used from the options object is a strict flag which indicates whether or not utf8.decode should reject characters encoded with more bytes than neccessary and characters reserved for utf-16 surrogate pairs.
By default it is set to true and the function will raise an Error on any illegal input.
None that I am aware of at the moment having tested in Firefox 11 and Chromium 18 under Linux on amd64. Bug reports and/or pull requests welcome at https://github.com/bwhmather/js-utf8 If you have any problems I will do my best to help.