added more docs

README.md

@@ -2,11 +2,11 @@
 
 A simple backoff algorithm in Go (Golang)
 
+[![GoDoc](https://godoc.org/github.com/jpillora/backoff?status.svg)](https://godoc.org/github.com/jpillora/backoff)
+
 # Usage
 
-Starts at `Min`, multiplied by `Factor` every call to
+Backoff is a `time.Duration` counter. It starts at `Min`. After every call to `Duration()` it is  multiplied by `Factor`. It is capped at `Max`. It returns to `Min` on every call to `Reset()`. Used in conjunction with the `time` package.
-`Duration()` where it is capped at `Max`. Commonly used
-in conjunction with `time.Sleep(duration)`.
 
 ``` go
 

backoff.go

@@ -5,13 +5,22 @@ import (
 	"time"
 )
 
+//Backoff is a time.Duration counter. It starts at Min.
+//After every call to Duration() it is  multiplied by Factor.
+//It is capped at Max. It returns to Min on every call to Reset().
+//Used in conjunction with the time package.
 type Backoff struct {
+	//Factor is the multiplying factor for each increment step
 	attempts, Factor int
-	curr, Min, Max   time.Duration
+	//Min and Max are the minimum and maximum values of the counter
+	curr, Min, Max time.Duration
 }
 
+//Returns the current value of the counter and then
+//multiplies it Factor
 func (b *Backoff) Duration() time.Duration {
-	//abit hacky though, if zero-value, apply defaults
+	//Zero-values are nonsensical, so we use
+	//them to apply defaults
 	if b.Min == 0 {
 		b.Min = 100 * time.Millisecond
 	}
@@ -33,6 +42,7 @@ func (b *Backoff) Duration() time.Duration {
 	return time.Duration(math.Min(ms, float64(b.Max)))
 }
 
+//Resets the current value of the counter back to Min
 func (b *Backoff) Reset() {
 	b.attempts = 0
 }