Use float values between 0 and 1

1 files changed, 26 insertions, 12 deletions

diff --git a/progress.go b/progress.go
index 4c2414e..da7cef0 100644
--- a/progress.go
+++ b/progress.go
@@ -1,3 +1,21 @@
+// Package progress implements a simple command line progress bar.
+//
+// Example:
+//
+//	import (
+//		time"
+//
+//		"gitlab.com/rhogenson/progress-bar/progress"
+//	)
+//
+//	func main() {
+//		b := new(progress.Bar)
+//		for i := range 100 {
+//			b.Set(float64(i)/100)
+//			b.Print()
+//			time.Sleep(time.Second)
+//		}
+//	}
 package progress
 
 import (
@@ -14,28 +32,24 @@ const measurements = 20
 
 type measurement struct {
 	t time.Time
-	i int
+	i float64
 }
 
+// Bar is a progess bar. The zero value is ready for use.
 type Bar struct {
-	max          int
 	measurements vecdeque.DQ[measurement]
 	cols         int
 }
 
-func New(max int) *Bar {
-	b := &Bar{max: max}
-	b.measurements.Grow(measurements)
-	return b
-}
-
-func (b *Bar) Set(i int) {
+// Set sets the current value to val. val must be between 0 and 1, inclusive.
+func (b *Bar) Set(val float64) {
 	if b.measurements.Len() == measurements {
 		b.measurements.PopFront()
 	}
-	b.measurements.PushBack(measurement{time.Now(), i})
+	b.measurements.PushBack(measurement{time.Now(), val})
 }
 
+// Print shows the progress bar on standard error.
 func (b *Bar) Print() {
 	first := b.measurements.Get(0)
 	last := b.measurements.Get(b.measurements.Len() - 1)
@@ -43,10 +57,10 @@ func (b *Bar) Print() {
 	delta := last.i - first.i
 	eta := time.Duration(-1)
 	if delta != 0 {
-		eta = time.Duration(float64(b.max-last.i) / float64(delta) * float64(deltaT))
+		eta = time.Duration(float64(deltaT) * (1 - last.i) / delta)
 	}
 
-	p := last.i * b.cols / b.max
+	p := int(last.i * float64(b.cols))
 	if b.cols == 0 {
 		var err error
 		if b.cols, _, err = term.GetSize(int(os.Stderr.Fd())); err != nil {