replace bytes.Buffer with strings.Builder

Author: 3cb

format.go

@@ -2,8 +2,8 @@
 package main
 
 import (
-	"bytes"
 	"math"
+	"strings"
 )
 
 // MaxLengths is used to format spaces for printing
@@ -36,23 +36,23 @@ type FmtPrint struct {
 
 // fmtColHdr formats column headers and returns a string
 func fmtColHdr(max *MaxLengths) string {
-	buf := bytes.Buffer{}
-	buf.WriteString(" Product")
-	buf.WriteString(setSpc(max.Price, "Price"))
-	buf.WriteString(setSpc(max.Size, "Last Size"))
-	buf.WriteString(setSpc(max.Change, "Change"))
-	buf.WriteString(setSpc(max.Bid, "Bid"))
-	buf.WriteString(setSpc(max.Ask, "Ask"))
-	buf.WriteString(setSpc(max.High, "High"))
-	buf.WriteString(setSpc(max.Low, "Low"))
-	buf.WriteString(setSpc(max.Volume, "Volume"))
-	buf.WriteString(" ")
-	return buf.String()
+	b := strings.Builder{}
+	b.WriteString(" Product")
+	b.WriteString(setSpc(max.Price, "Price"))
+	b.WriteString(setSpc(max.Size, "Last Size"))
+	b.WriteString(setSpc(max.Change, "Change"))
+	b.WriteString(setSpc(max.Bid, "Bid"))
+	b.WriteString(setSpc(max.Ask, "Ask"))
+	b.WriteString(setSpc(max.High, "High"))
+	b.WriteString(setSpc(max.Low, "Low"))
+	b.WriteString(setSpc(max.Volume, "Volume"))
+	b.WriteString(" ")
+	return b.String()
 }
 
 // fmtTitle returns header(or footer with empty string parameter) centered based on total max length, left margin(1), product column(7), and spaces between columns(48)
 func fmtTitle(title string, total int) string {
-	buf := bytes.Buffer{}
+	b := strings.Builder{}
 	var lMargin, rMargin int
 	whitespace := total - len(title)
 
@@ -65,11 +65,11 @@ func fmtTitle(title string, total int) string {
 	}
 
 	for i := 0; i < lMargin; i++ {
-		buf.WriteString(" ")
+		b.WriteString(" ")
 	}
-	buf.WriteString(title)
+	b.WriteString(title)
 	for i := 0; i < rMargin; i++ {
-		buf.WriteString(" ")
+		b.WriteString(" ")
 	}
-	return buf.String()
+	return b.String()
 }

product.go

@@ -2,7 +2,6 @@
 package main
 
 import (
-	"bytes"
 	"strings"
 
 	"github.com/fatih/color"
@@ -37,18 +36,18 @@ type Product struct {
 
 // fmtRow formats all Product data into a single row so it can be printed
 func (p Product) fmtRow() string {
-	buf := bytes.Buffer{}
-	buf.WriteString(" ")
-	buf.WriteString(strings.Join(strings.Split(p.ID, "-"), "/"))
-	buf.WriteString(p.Price)
-	buf.WriteString(p.Size)
-	buf.WriteString(p.Change)
-	buf.WriteString(p.Bid)
-	buf.WriteString(p.Ask)
-	buf.WriteString(p.High)
-	buf.WriteString(p.Low)
-	buf.WriteString(p.Volume)
-	return buf.String()
+	b := strings.Builder{}
+	b.WriteString(" ")
+	b.WriteString(strings.Join(strings.Split(p.ID, "-"), "/"))
+	b.WriteString(p.Price)
+	b.WriteString(p.Size)
+	b.WriteString(p.Change)
+	b.WriteString(p.Bid)
+	b.WriteString(p.Ask)
+	b.WriteString(p.High)
+	b.WriteString(p.Low)
+	b.WriteString(p.Volume)
+	return b.String()
 }
 
 // Stats contains 24 hour data from REST API:
@@ -71,27 +70,27 @@ type Ticker struct {
 
 // setSpc adds space in front of string based on max length for single quote
 func setSpc(max int, orig string) string {
-	buf := bytes.Buffer{}
-	buf.WriteString("     ")
+	b := strings.Builder{}
+	b.WriteString("     ")
 	diff := max - len(orig)
 	if diff > 0 {
 		for i := 0; i < diff; i++ {
-			buf.WriteString(" ")
+			b.WriteString(" ")
 		}
 	}
-	buf.WriteString(orig)
-	return buf.String()
+	b.WriteString(orig)
+	return b.String()
 }
 
 // setSpcStrm adds spaces to string according to max lengths calculated in single quote
 func setSpcStrm(max int, orig string) string {
-	buf := bytes.Buffer{}
+	b := strings.Builder{}
 	diff := 5 + max - len(orig)
 	if diff > 0 {
 		for i := 0; i < diff; i++ {
-			buf.WriteString(" ")
+			b.WriteString(" ")
 		}
 	}
-	buf.WriteString(orig)
-	return buf.String()
+	b.WriteString(orig)
+	return b.String()
 }

round.go

@@ -2,7 +2,6 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
 	"strconv"
 	"strings"
@@ -50,10 +49,10 @@ func setDelta(price string, open string) string {
 	p, _ := strconv.ParseFloat(price, 64)
 	o, _ := strconv.ParseFloat(open, 64)
 	delta := ((p - o) / o) * 100
-	buf := bytes.Buffer{}
-	buf.WriteString(strconv.FormatFloat(delta, 'f', 2, 64))
-	buf.WriteString("%")
-	return buf.String()
+	b := strings.Builder{}
+	b.WriteString(strconv.FormatFloat(delta, 'f', 2, 64))
+	b.WriteString("%")
+	return b.String()
 }
 
 // SetColor uses the delta filed of Product type to set color either red or green