Function query_value_update

plugins/experimental/txn_box/plugin/src/query.cc:99–143

}

TextView
query_value_update(Context &ctx, TextView qs, TextView name, Feature const &value, bool case_p, bool force_equal_p)
{
  TextView zret;
  bool     nv_is_nil_p = (value.value_type() == NIL);
  if (qs.empty()) {
    if (!nv_is_nil_p) {
      zret = ctx.render_transient([&](BufferWriter &w) { w.print("{}={}", name, std::get<STRING>(value)); });
    }
  } else { // invariant - query string was not empty.
    auto &&[k, v] = ts::query_value_for(qs, name, case_p);
    if (k.empty()) { // not found at all.
      if (!nv_is_nil_p) {
        zret = ctx.render_transient([&](BufferWriter &w) { w.print("{}&{}={}", qs, name, value); });
      }
    } else {
      // Make a note if there was no value but an '=' anyway.
      bool equal_p = force_equal_p || (v.empty() && (v.data() != k.end()));
      // Prefix is the part before the name.
      TextView prefix{qs.data(), k.data()};
      // Suffix is the part after the value.
      TextView suffix{v.end(), qs.end()};
      if (!nv_is_nil_p) {
        zret = ctx.render_transient([&, k = k](BufferWriter &w) {
          w.write(prefix).write(k);
          if (equal_p || !(value.index() == IndexFor(STRING) && std::get<IndexFor(STRING)>(value).empty())) {
            w.print("={}", value);
          }
          w.write(suffix);
        });
      } else { // NIL, remove the pair.
        prefix.rtrim("&;"_tv);
        suffix.ltrim("&;"_tv);
        if (suffix.empty()) {
          zret = prefix;
        } else if (prefix.empty()) {
          zret = suffix;
        } else { // neither is empty.
          zret = ctx.render_transient([&](BufferWriter &w) { w.print("{}&{}", prefix, suffix); });
        }
      }
    }
  }
  return zret;
}

} // namespace
/* ------------------------------------------------------------------------------------ */