0.9.4: Add Must* methods (#8)

This release adds methods starting with `Must` that panic instead of throwing an error.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.9.4: Add `Must*` methods
+
+This release adds methods starting with `Must` that panic instead of throwing an error.
+
 ## 0.9.3: Custom label support
 
 Each of the metric methods now allow adding extra labels:

README.md

@@ -41,7 +41,7 @@ testCounter, err := m.CreateCounterGeo(
 testCounter.Increment(net.ParseIP("127.0.0.1"))
 ```
 
-If you need a metric that can be decremented or set directly you can use the `Gauge` type instead.
+If you need a metric that can be decremented or set directly you can use the `Gauge` type instead. Each `Create*` method also has a counterpart named `MustCreate*`, which panics instead of returning an error.
 
 ### Custom labels
 

collector.go

@@ -153,17 +153,33 @@ type Collector interface {
 	// CreateCounter creates a monotonic (increasing) counter with the specified name and help text.
 	CreateCounter(name string, unit string, help string) (SimpleCounter, error)
 
+	// MustCreateCounter creates a monotonic (increasing) counter with the specified name and help text. Panics if an
+	// error occurs.
+	MustCreateCounter(name string, unit string, help string) SimpleCounter
+
 	// CreateCounterGeo creates a monotonic (increasing) counter that is labeled with the country from the GeoIP lookup
-	//                  with the specified name and help text.
+	// with the specified name and help text.
 	CreateCounterGeo(name string, unit string, help string) (SimpleGeoCounter, error)
 
+	// MustCreateCounterGeo creates a monotonic (increasing) counter that is labeled with the country from the GeoIP
+	// lookup with the specified name and help text. Panics if an error occurs.
+	MustCreateCounterGeo(name string, unit string, help string) SimpleGeoCounter
+
 	// CreateGauge creates a freely modifiable numeric gauge with the specified name and help text.
 	CreateGauge(name string, unit string, help string) (SimpleGauge, error)
 
+	// MustCreateGauge creates a freely modifiable numeric gauge with the specified name and help text. Panics if an
+	// error occurs.
+	MustCreateGauge(name string, unit string, help string) SimpleGauge
+
 	// CreateGaugeGeo creates a freely modifiable numeric gauge that is labeled with the country from the GeoIP lookup
-	//                with the specified name and help text.
+	// with the specified name and help text.
 	CreateGaugeGeo(name string, unit string, help string) (SimpleGeoGauge, error)
 
+	// MustCreateGaugeGeo creates a freely modifiable numeric gauge that is labeled with the country from the GeoIP
+	// lookup with the specified name and help text. Panics if an error occurs.
+	MustCreateGaugeGeo(name string, unit string, help string) SimpleGeoGauge
+
 	// ListMetrics returns a list of metrics metadata stored in the collector.
 	ListMetrics() []Metric
 

collector_impl.go

@@ -16,6 +16,38 @@ type collector struct {
 	values     map[string]*metricValue
 }
 
+func (c *collector) MustCreateCounter(name string, unit string, help string) SimpleCounter {
+	counter, err := c.CreateCounter(name, unit, help)
+	if err != nil {
+		panic(err)
+	}
+	return counter
+}
+
+func (c *collector) MustCreateCounterGeo(name string, unit string, help string) SimpleGeoCounter {
+	counter, err := c.CreateCounterGeo(name, unit, help)
+	if err != nil {
+		panic(err)
+	}
+	return counter
+}
+
+func (c *collector) MustCreateGauge(name string, unit string, help string) SimpleGauge {
+	gauge, err := c.CreateGauge(name, unit, help)
+	if err != nil {
+		panic(err)
+	}
+	return gauge
+}
+
+func (c *collector) MustCreateGaugeGeo(name string, unit string, help string) SimpleGeoGauge {
+	gauge, err := c.CreateGaugeGeo(name, unit, help)
+	if err != nil {
+		panic(err)
+	}
+	return gauge
+}
+
 type metricValue struct {
 	metricValueMap map[string]*MetricValue
 	metricValues   []*MetricValue