Minor cleanups in sdk/metric/aggregator (#781)

* Typo

* Swap order of ddsketch.New for consistency w/ histogram.New

api/global/internal/benchmark_test.go

@@ -63,9 +63,9 @@ func (*benchFixture) AggregatorFor(descriptor *metric.Descriptor) export.Aggrega
 		if strings.HasSuffix(descriptor.Name(), "minmaxsumcount") {
 			return minmaxsumcount.New(descriptor)
 		} else if strings.HasSuffix(descriptor.Name(), "ddsketch") {
-			return ddsketch.New(ddsketch.NewDefaultConfig(), descriptor)
+			return ddsketch.New(descriptor, ddsketch.NewDefaultConfig())
 		} else if strings.HasSuffix(descriptor.Name(), "array") {
-			return ddsketch.New(ddsketch.NewDefaultConfig(), descriptor)
+			return ddsketch.New(descriptor, ddsketch.NewDefaultConfig())
 		}
 	}
 	return nil

exporters/metric/stdout/stdout_test.go

@@ -240,7 +240,7 @@ func TestStdoutValueRecorderFormat(t *testing.T) {
 func TestStdoutNoData(t *testing.T) {
 	desc := metric.NewDescriptor("test.name", metric.ValueRecorderKind, metric.Float64NumberKind)
 	for name, tc := range map[string]export.Aggregator{
-		"ddsketch":       ddsketch.New(ddsketch.NewDefaultConfig(), &desc),
+		"ddsketch":       ddsketch.New(&desc, ddsketch.NewDefaultConfig()),
 		"minmaxsumcount": minmaxsumcount.New(&desc),
 	} {
 		tc := tc

sdk/metric/aggregator/ddsketch/ddsketch.go

@@ -43,7 +43,7 @@ var _ aggregator.MinMaxSumCount = &Aggregator{}
 var _ aggregator.Distribution = &Aggregator{}
 
 // New returns a new DDSketch aggregator.
-func New(cfg *Config, desc *metric.Descriptor) *Aggregator {
+func New(desc *metric.Descriptor, cfg *Config) *Aggregator {
 	return &Aggregator{
 		cfg:        cfg,
 		kind:       desc.NumberKind(),

sdk/metric/aggregator/ddsketch/ddsketch_test.go

@@ -34,7 +34,7 @@ func (ut *updateTest) run(t *testing.T, profile test.Profile) {
 	ctx := context.Background()
 
 	descriptor := test.NewAggregatorTest(metric.ValueRecorderKind, profile.NumberKind)
-	agg := New(NewDefaultConfig(), descriptor)
+	agg := New(descriptor, NewDefaultConfig())
 
 	all := test.NewNumbers(profile.NumberKind)
 	for i := 0; i < count; i++ {
@@ -94,8 +94,8 @@ func (mt *mergeTest) run(t *testing.T, profile test.Profile) {
 	ctx := context.Background()
 	descriptor := test.NewAggregatorTest(metric.ValueRecorderKind, profile.NumberKind)
 
-	agg1 := New(NewDefaultConfig(), descriptor)
-	agg2 := New(NewDefaultConfig(), descriptor)
+	agg1 := New(descriptor, NewDefaultConfig())
+	agg2 := New(descriptor, NewDefaultConfig())
 
 	all := test.NewNumbers(profile.NumberKind)
 	for i := 0; i < count; i++ {

sdk/metric/benchmark_test.go

@@ -67,9 +67,9 @@ func (*benchFixture) AggregatorFor(descriptor *metric.Descriptor) export.Aggrega
 		if strings.HasSuffix(descriptor.Name(), "minmaxsumcount") {
 			return minmaxsumcount.New(descriptor)
 		} else if strings.HasSuffix(descriptor.Name(), "ddsketch") {
-			return ddsketch.New(ddsketch.NewDefaultConfig(), descriptor)
+			return ddsketch.New(descriptor, ddsketch.NewDefaultConfig())
 		} else if strings.HasSuffix(descriptor.Name(), "array") {
-			return ddsketch.New(ddsketch.NewDefaultConfig(), descriptor)
+			return ddsketch.New(descriptor, ddsketch.NewDefaultConfig())
 		}
 	}
 	return nil

sdk/metric/integrator/simple/simple.go

@@ -46,7 +46,7 @@ type (
 	}
 
 	batch struct {
-		// RWMutex implements locking for the `CheckpoingSet` interface.
+		// RWMutex implements locking for the `CheckpointSet` interface.
 		sync.RWMutex
 		values map[batchKey]batchValue
 	}

sdk/metric/selector/simple/simple.go

@@ -91,7 +91,7 @@ func (selectorInexpensive) AggregatorFor(descriptor *metric.Descriptor) export.A
 func (s selectorSketch) AggregatorFor(descriptor *metric.Descriptor) export.Aggregator {
 	switch descriptor.MetricKind() {
 	case metric.ValueObserverKind, metric.ValueRecorderKind:
-		return ddsketch.New(s.config, descriptor)
+		return ddsketch.New(descriptor, s.config)
 	default:
 		return sum.New()
 	}