🚀 go-pugleaf

Hi,
I'm planning to add syntax-highlighting to an editor I've already
written. I've read Robert Dunn's article entitled "Faster rich edit
syntax highlighting" which saves me a lot of effort and trouble.

All the keywords I'd like to display in a specific color begin with
a backslash, so it's quite easy to search the text for the backslashes
using EM_FINDTEXTEX. The problem is how to find quite quickly the end
of those keywords :
each keyword ends just before the first non-letter character following
the backslash, for instance, if we meet :
  ...  \begin{quote} ...
the keyword is "\begin" because the curly brace is the first non-letter
character after the "\"
(I can't store all the keywords in an array, because they are too many
and each user can add new keywords)

My question is :
What is the fastest method to read a few characters after finding a 
backslash,
that is when we just know the backslah zero-based position given by 
EM_FINDTEXTEX ?

Of course I could use EM_LINEFROMCHAR and EM_LINEINDEX to get the line 
and column numbers and then use
RichEdit->Lines->Strings[lineNumber]...
but I don't think that would be very fast.
Perhaps I could use EM_GETSELTEXT to store let's say the 20 or 30 next
characters in a buffer ...
Any idea  would be welcome.
(for those who want to know I use that program to edit TeX and LaTeX code)

Michel.