Suppose I want do define a special style for every character A that appears after the character B. If I do this?
<context id="AAA" style-ref="punct">
<match>[B][A]</match>
</context>
then B itself gets highlighted, which I do not want; I want to highlight only the A. How can I do this?
Use lookbehind:
<match>(?<=[B])[A]</match>
(The <
of the lookbehind operator needs to be escaped in XML.)