Function find_earliest_match

crawl-ref/source/stringutil.h:91–123

 */
template<class Enum, class Pred, class NameFunc>
Enum find_earliest_match(const string &spec, Enum begin, Enum end,
                         Pred pred, NameFunc namefunc)
{
    Enum selected = end;
    const size_t speclen = spec.length();
    size_t bestpos = string::npos;
    size_t bestlen = string::npos;
    for (size_t i = begin; i < (size_t) end; ++i)
    {
        const Enum curr = static_cast<Enum>(i);

        if (!pred(curr))
            continue;

        const string name = lowercase_string(namefunc(curr));
        const size_t pos = name.find(spec);
        const size_t len = name.length();

        if (pos < bestpos || pos == 0 && len < bestlen)
        {
            // Exit early if we found an exact match.
            if (pos == 0 && len == speclen)
                return curr;

            // npos is never less than bestpos, so the spec was found.
            bestpos = pos;
            if (pos == 0)
                bestlen = len;
            selected = curr;
        }
    }
    return selected;
}

/**
 * Join together strings computed by a function applied to some elements