wcwidth

wcwidth is a small library for calculating the terminal display width of a string. This is often the same as Stdlib.String.length, but differs when 'wide' characters (such as CJK characters or emoji) are used.

The wcwidth and wcswidth C functions are actually defined as part of the POSIX standard (see man 3 wcwidth, for example). This library, however, uses a very minimal reimplementation of the wcwidth Python package.

In principle, this should be a standalone library, not bundled as part of whatwhat. However, I (Jon) am not yet confident enough in the correctness of the code to publish it on OPAM.

The API is very simple: it consists of three functions, and is documented at Wcwidth.