How to format characters in a custom eclipse editor plugin

I'm writing a custom editor plugin in Eclipse and I'm trying to figure out how to format certain character sequences with symbols. So in the editor view typing -> would be replaced with →. I don't want to modify the underlying document content, just how开发者_C百科 the characters are displayed. The TextAttribute class only allows me to change the style of the text, not what is actually displayed.

You would probably have to copy all of the Eclipse classes having to do with the editor into your own project so you could modify the method(s) that displays characters on the screen.