static string queryMetaFieldString(MetaInfo & meta, const string & name)

static string queryMetaStrings(EvalState & state, DrvInfo & drv, const string & name)

    MetaValue value = meta[name];
    if (value.type != MetaValue::tpString) return "";
    return value.stringValue;
}
static int queryMetaFieldInt(MetaInfo & meta, const string & name, int def)
{
    MetaValue value = meta[name];
    if (value.type == MetaValue::tpInt) return value.intValue;
    if (value.type == MetaValue::tpString) {
        int n;
        if (string2Int(value.stringValue, n)) return n;
    }
    return def;
}
static string queryMetaField(MetaInfo & meta, const string & name)
{
    string res;
    MetaValue value = meta[name];
    if (value.type == MetaValue::tpString)
        res = value.stringValue;
    else if (value.type == MetaValue::tpStrings) {
        foreach (Strings::const_iterator, i, value.stringValues) {
            if (res.size() != 0) res += ", ";
            res += *i;

    Value * v = drv.queryMeta(name);
    if (v) {
        state.forceValue(*v);
        if (v->type == tString)
            return v->string.s;
        else if (v->type == tList) {
            string res = "";
            for (unsigned int n = 0; n < v->list.length; ++n) {
                Value v2(*v->list.elems[n]);
                state.forceValue(v2);
                if (v2.type == tString) {
                    if (res.size() != 0) res += ", ";
                    res += v2.string.s;
                }
            }
            return res;

    return res;

    return "";

        DrvInfo drv;

        DrvInfo drv(state);

            DrvInfo::Outputs outputs = drv.queryOutputs(state);

            DrvInfo::Outputs outputs = drv.queryOutputs();

            xmlAttrs["drvPath"] = drvPath = drv.queryDrvPath(state);
            MetaInfo meta = drv.queryMetaInfo(state);
            xmlAttrs["description"] = queryMetaFieldString(meta, "description");
            xmlAttrs["longDescription"] = queryMetaFieldString(meta, "longDescription");
            xmlAttrs["license"] = queryMetaField(meta, "license");
            xmlAttrs["homepage"] = queryMetaFieldString(meta, "homepage");
            xmlAttrs["maintainers"] = queryMetaField(meta, "maintainers");

            xmlAttrs["drvPath"] = drvPath = drv.queryDrvPath();
            xmlAttrs["description"] = drv.queryMetaString("description");
            xmlAttrs["longDescription"] = drv.queryMetaString("longDescription");
            xmlAttrs["license"] = queryMetaStrings(state, drv, "license");
            xmlAttrs["homepage"] = drv.queryMetaString("homepage");
            xmlAttrs["maintainers"] = queryMetaStrings(state, drv, "maintainers");

            int prio = queryMetaFieldInt(meta, "schedulingPriority", 100);
            xmlAttrs["schedulingPriority"] = int2String(prio);

            xmlAttrs["schedulingPriority"] = int2String(drv.queryMetaInt("schedulingPriority", 100));

            int timeout = queryMetaFieldInt(meta, "timeout", 36000);
            xmlAttrs["timeout"] = int2String(timeout);

            xmlAttrs["timeout"] = int2String(drv.queryMetaInt("timeout", 36000));

            int maxsilent = queryMetaFieldInt(meta, "maxSilent", 3600);
            xmlAttrs["maxSilent"] = int2String(maxsilent);

            xmlAttrs["maxSilent"] = int2String(drv.queryMetaInt("maxSilent", 3600));