Update README.md

README.md

@@ -1,7 +1,8 @@
 # vimebu
 Vimebu is a small library that provides a builder to create VictoriaMetrics compatible metrics.
 
-### Usage
+## Usage
+### Builder pattern
 ```go
 import (
     "github.com/wazazaby/vimebu"
@@ -70,3 +71,67 @@ func getHTTPRequestCounter(path string) *vm.Counter {
     return vm.GetOrCreateCounter(metric)
 }
 ```
+
+### Functional pattern
+Vimebu also exposes another builder using a more functional pattern. Here are the same example as above using it.
+```go
+import (
+    "github.com/wazazaby/vimebu"
+    vm "github.com/VictoriaMetrics/metrics"
+)
+
+var (
+    requestsTotalCounter = vm.NewCounter(
+        vimebu.BuilderFunc("request_total", vimebu.WithLabel("path", "/foo/bar")), // request_total{path="/foo/bar"}
+    )
+
+    responseSizeHistogram = vm.NewHistogram(
+        vimebu.BuilderFunc("response_size"), // response_size{}
+    )
+)
+```
+
+```go
+import (
+    "net"
+    "github.com/wazazaby/vimebu"
+    vm "github.com/VictoriaMetrics/metrics"
+)
+
+func getCassandraQueryCounter(name string, host net.IP) *vm.Counter {
+    metric := vimebu.BuilderFunc("cassandra_query_total",
+        vimebu.WithLabel("name", name),
+        vimebu.WithLabel("host", host.String()),
+    ) // cassandra_query_total{name="beep",host="1.2.3.4"}
+    return vm.GetOrCreateCounter(metric)
+}
+```
+
+```go
+import (
+    "github.com/wazazaby/vimebu"
+    vm "github.com/VictoriaMetrics/metrics"
+)
+
+func getHTTPRequestCounter(host string) *vm.Counter {
+    metric := vimebu.BuilderFunc("api_http_requests_total",
+        vimebu.WithLabelCond(func() bool { return host != "" }, "host", host),
+    ) // api_http_requests_total{} or api_http_requests_total{host="api.app.com"}
+    return vm.GetOrCreateCounter(metric)
+}
+```
+
+```go
+import (
+    "github.com/wazazaby/vimebu"
+    vm "github.com/VictoriaMetrics/metrics"
+)
+
+func getHTTPRequestCounter(path string) *vm.Counter {
+    metric := vimebu.BuilderFunc(
+        "api_http_requests_total",
+        vimebu.WithLabelQuote("path", path"),
+    )  // api_http_requests_total{path="some/bro\"ken/path"}
+    return vm.GetOrCreateCounter(metric)
+}
+```