nit

README.md

@@ -1 +1,11 @@
 base10 encoding of primitive types
+
+```bash
+$ go test -bench=. -benchmem . 
+goos: darwin
+goarch: arm64
+pkg: github.com/ndx-technologies/base10quant
+cpu: Apple M3 Max
+BenchmarkL9/string-16           96114614                12.32 ns/op           16 B/op          1 allocs/op
+BenchmarkL9/from_string-16      160158512                7.478 ns/op           0 B/op          0 allocs/op
+```

l9.go

@@ -4,9 +4,12 @@ import (
 	"errors"
 )
 
-var ErrInvalidFormat = errors.New("invalid format")
+var ErrL9InvalidFormat = errors.New("l9: invalid format")
 
-const MaxL9 = 999_999_999
+const (
+	MaxL9 = 999_999_999
+	MinL9 = 0
+)
 
 // L9 is base10 chars encoding least significant 9 decimals of uint32.
 type L9 struct{ v uint32 }
@@ -44,12 +47,12 @@ func (s L9) MarshalText() ([]byte, error) {
 
 func (s *L9) UnmarshalText(b []byte) error {
 	if len(b) != 9 {
-		return ErrInvalidFormat
+		return ErrL9InvalidFormat
 	}
 	s.v = 0
 	for i := 0; i < 9; i++ {
 		if b[i] < '0' || b[i] > '9' {
-			return ErrInvalidFormat
+			return ErrL9InvalidFormat
 		}
 		s.v *= 10
 		s.v += uint32(b[i] - '0')

l9_test.go

@@ -1,11 +1,20 @@
 package base10quant_test
 
 import (
+	"fmt"
+	"math/rand"
 	"testing"
 
 	"github.com/ndx-technologies/base10quant"
 )
 
+func ExampleL9() {
+	var v base10quant.L9
+	v.UnmarshalText([]byte("123456789"))
+	fmt.Println(v)
+	// Output: 123456789
+}
+
 func TestL9(t *testing.T) {
 	t.Run("ok", func(t *testing.T) {
 		tests := []struct {
@@ -89,3 +98,42 @@ func FuzzL9(f *testing.F) {
 		}
 	})
 }
+
+func BenchmarkL9(b *testing.B) {
+	b.Run("string", func(b *testing.B) {
+		x := rand.Uint32()
+		v := base10quant.L9FromUint32(x)
+		var s string
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			s = v.String()
+		}
+
+		if len(s) == 0 {
+			b.Fatal("unexpected empty string")
+		}
+	})
+
+	b.Run("from_string", func(b *testing.B) {
+		x := rand.Uint32()
+		v := base10quant.L9FromUint32(x)
+		s := v.String()
+		var err error
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			v, err = base10quant.L9FromString(s)
+		}
+
+		if len(s) == 0 {
+			b.Fatal("unexpected empty string")
+		}
+		if v == (base10quant.L9{}) {
+			b.Fatal("unexpected empty value")
+		}
+		if err != nil {
+			b.Fatal(err)
+		}
+	})
+}