module metrics [params] pub struct Metric { name string [required] labels [][2]string } [inline] fn join_two_array(arr [2]string) string { return arr[0] + '=' + arr[1] } pub fn (m &Metric) str() string { if m.labels.len == 0 { return m.name } return '$m.name{${m.labels.map(join_two_array(it)).join(',')}}' } interface MetricsCollector { counter_register(value u64, metric Metric) counter_increment(metric Metric) counter_decrement(metric Metric) }