dispatch method
Attempts to dispatch a command. If registered, calls the handler and returns the result; if unregistered, returns null (allowing the caller to fall back to default handling).
Implementation
LatexNode? dispatch(
String cmdName,
LatexParserContext ctx,
LatexTokenStream stream,
) {
final handler = _handlers[cmdName];
if (handler == null) return null;
return handler(cmdName, ctx, stream);
}