private SampleFamily valueMatch(CompType compType,
                                    double compValue,
                                    Function3<CompType, Double, Double, Boolean> op) {
        Sample[] ss = Arrays.stream(samples)
                            .filter(sample -> op.apply(compType, sample.value, compValue)).toArray(Sample[]::new);
        return ss.length > 0 ? SampleFamily.build(this.context, ss) : EMPTY;
    }
Following operations are used in DSL
oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/dsl/SampleFamily.java