Vim 7.3 comes with a new feature called "conceal." One application of it is dynamically displaying unicode glyph of a given combination of patterns or keywords. For instance, we can display unicode right arrow → on the screen with ascii right arrow in the buffer. There has been vim coneal syntax files for different programming langauges, like
This one is a conceal syntax definition for OCaml.
Drop the ocaml.vim to ~/.vim/after/syntax (Linux/Mac OS X/BSD) or ~/vimfiles/after/syntax folder (Windows)
Copyright (c) Paul Meng. Distributed under the same terms as Vim itself.
Modified by Anthony Scemama.