still yet faster commaf
benchmark old ns/op new ns/op delta
BenchmarkCommaf 1882 1484 -21.15%
diff --git a/comma.go b/comma.go
index c6bcebc..c4c7fcf 100644
--- a/comma.go
+++ b/comma.go
@@ -1,6 +1,7 @@
package humanize
import (
+ "bytes"
"math/big"
"strconv"
"strings"
@@ -40,28 +41,35 @@
//
// e.g. Comma(834142.32) -> 834,142.32
func Commaf(v float64) string {
- sign := ""
+ buf := &bytes.Buffer{}
if v < 0 {
- sign = "-"
+ buf.Write([]byte{'-'})
v = 0 - v
}
+ comma := []byte{','}
+
parts := strings.Split(strconv.FormatFloat(v, 'f', -1, 64), ".")
- segs := make([]string, 0, len(parts[0])/3)
pos := 0
if len(parts[0])%3 != 0 {
pos += len(parts[0]) % 3
- segs = append(segs, parts[0][:pos])
+ buf.WriteString(parts[0][:pos])
+ if len(parts[0]) > pos+2 {
+ buf.Write(comma)
+ }
}
for ; pos < len(parts[0]); pos += 3 {
- segs = append(segs, parts[0][pos:pos+3])
+ buf.WriteString(parts[0][pos : pos+3])
+ if len(parts[0]) > pos+3 {
+ buf.Write(comma)
+ }
}
- rv := sign + strings.Join(segs, ",")
if len(parts) > 1 {
- rv += "." + parts[1]
+ buf.Write([]byte{'.'})
+ buf.WriteString(parts[1])
}
- return rv
+ return buf.String()
}
// BigComma produces a string form of the given big.Int in base 10
