Function wordwrap_line

crawl-ref/source/stringutil.cc:173–270

The provided string is consumed!

// The provided string is consumed!
string wordwrap_line(string &s, int width, bool tags, bool indent, int force_indent)
{
    ASSERT(width > 0);

    const char *cp0 = s.c_str();
    const char *cp = cp0, *space = 0;
    char32_t c;
    bool seen_nonspace = false;

    while (int clen = utf8towc(&c, cp))
    {
        int cw = wcwidth(c);
        if (c == ' ')
        {
            if (seen_nonspace)
                space = cp;
        }
        else if (c == '\n')
        {
            space = cp;
            break;
        }
        else
            seen_nonspace = true;

        if (c == '<' && tags)
        {
            ASSERT(cw == 1);
            if (cp[1] == '<') // "<<" escape
            {
                // Note: this must be after a possible wrap, otherwise we could
                // split the escape between lines.
                cp++;
            }
            else
            {
                cw = 0;
                // Skip the whole tag.
                while (*cp != '>')
                {
                    if (!*cp)
                    {
                        // Everything so far fitted, report error.
                        string ret = s + ">";
                        s = "<lightred>ERROR: string above had unterminated tag</lightred>";
                        return ret;
                    }
                    cp++;
                }
            }
        }

        if (cw > width)
            break;

        if (cw >= 0)
            width -= cw;
        cp += clen;