+ if (!is_bibtex_)
+ return docstring();
+ return operator[]("crossref");
+}
+
+
+namespace {
+
+string parseOptions(string const & format, string & optkey,
+ string & ifpart, string & elsepart);
+
+// Calls parseOptions to deal with an embedded option, such as:
+// {%number%[[, no.~%number%]]}
+// which must appear at the start of format. ifelsepart gets the
+// whole of the option, and we return what's left after the option.
+// we return format if there is an error.
+string parseEmbeddedOption(string const & format, string & ifelsepart)
+{
+ LASSERT(format[0] == '{' && format[1] == '%', return format);
+ string optkey;
+ string ifpart;
+ string elsepart;
+ string const rest = parseOptions(format, optkey, ifpart, elsepart);
+ if (format == rest) { // parse error
+ LYXERR0("ERROR! Couldn't parse `" << format <<"'.");
+ return format;
+ }
+ LASSERT(rest.size() <= format.size(),
+ { ifelsepart = ""; return format; });
+ ifelsepart = format.substr(0, format.size() - rest.size());
+ return rest;
+}
+
+
+// Gets a "clause" from a format string, where the clause is
+// delimited by '[[' and ']]'. Returns what is left after the
+// clause is removed, and returns format if there is an error.
+string getClause(string const & format, string & clause)
+{
+ string fmt = format;
+ // remove '[['
+ fmt = fmt.substr(2);
+ // we'll remove characters from the front of fmt as we
+ // deal with them
+ while (!fmt.empty()) {
+ if (fmt[0] == ']' && fmt.size() > 1 && fmt[1] == ']') {
+ // that's the end
+ fmt = fmt.substr(2);
+ break;
+ }
+ // check for an embedded option
+ if (fmt[0] == '{' && fmt.size() > 1 && fmt[1] == '%') {
+ string part;
+ string const rest = parseEmbeddedOption(fmt, part);
+ if (fmt == rest) {
+ LYXERR0("ERROR! Couldn't parse embedded option in `" << format <<"'.");
+ return format;
+ }
+ clause += part;
+ fmt = rest;
+ } else { // it's just a normal character
+ clause += fmt[0];
+ fmt = fmt.substr(1);
+ }
+ }
+ return fmt;
+}
+
+
+// parse an options string, which must appear at the start of the
+// format parameter. puts the parsed bits in optkey, ifpart, and
+// elsepart and returns what's left after the option is removed.
+// if there's an error, it returns format itself.
+string parseOptions(string const & format, string & optkey,
+ string & ifpart, string & elsepart)
+{
+ LASSERT(format[0] == '{' && format[1] == '%', return format);
+ // strip '{%'
+ string fmt = format.substr(2);
+ size_t pos = fmt.find('%'); // end of key
+ if (pos == string::npos) {
+ LYXERR0("Error parsing `" << format <<"'. Can't find end of key.");
+ return format;
+ }
+ optkey = fmt.substr(0,pos);
+ fmt = fmt.substr(pos + 1);
+ // [[format]] should be next
+ if (fmt[0] != '[' || fmt[1] != '[') {
+ LYXERR0("Error parsing `" << format <<"'. Can't find '[[' after key.");
+ return format;
+ }
+
+ string curfmt = fmt;
+ fmt = getClause(curfmt, ifpart);
+ if (fmt == curfmt) {
+ LYXERR0("Error parsing `" << format <<"'. Couldn't get if clause.");
+ return format;
+ }
+
+ if (fmt[0] == '}') // we're done, no else clause
+ return fmt.substr(1);
+
+ // else part should follow
+ if (fmt[0] != '[' || fmt[1] != '[') {
+ LYXERR0("Error parsing `" << format <<"'. Can't find else clause.");
+ return format;
+ }
+
+ curfmt = fmt;
+ fmt = getClause(curfmt, elsepart);
+ // we should be done
+ if (fmt == curfmt || fmt[0] != '}') {
+ LYXERR0("Error parsing `" << format <<"'. Can't find end of option.");
+ return format;