// Package metricsql implements MetricsQL parser.
//
// This parser can parse PromQL. Additionally it can parse all the MetricsQL extensions.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL for details about MetricsQL extensions.
//
// Usage:
//
//    expr, err := metricsql.Parse(`sum(rate(foo{bar="baz"}[5m])) by (job)`)
//    if err != nil {
//        // parse error
//    }
//    // Now expr contains parsed MetricsQL as `*Expr` structs.
//    // See Parse examples for more details.
//
package metricsql