Add Float

floats.go

@@ -6,6 +6,42 @@ import (
 	"strings"
 )
 
+// Float is a `flag.Value` for a float argument.
+// The `BitSize` field is used for parsing when set.
+type Float struct {
+	BitSize int
+
+	Value float64
+	Text  string
+}
+
+// Help returns a string suitable for inclusion in a flag help message.
+func (fv *Float) Help() string {
+	var bitSize string
+	if fv.BitSize != 0 {
+		bitSize = fmt.Sprintf("%d-bit ", fv.BitSize)
+	}
+	return fmt.Sprintf("a %sfloat", bitSize)
+}
+
+// Set is flag.Value.Set
+func (fv *Float) Set(v string) error {
+	bitSize := fv.BitSize
+	if bitSize == 0 {
+		bitSize = 64
+	}
+	n, err := strconv.ParseFloat(v, bitSize)
+	if err == nil {
+		fv.Value = n
+		fv.Text = v
+	}
+	return err
+}
+
+func (fv *Float) String() string {
+	return fv.Text
+}
+
 // Floats is a `flag.Value` for float arguments.
 // The `BitSize` field is used for parsing when set.
 type Floats struct {

floats_test.go

@@ -8,6 +8,55 @@ import (
 	"github.com/sgreben/flagvar"
 )
 
+func TestFloat(t *testing.T) {
+	fv := flagvar.Float{}
+	var fs flag.FlagSet
+	fs.Var(&fv, "float", "")
+
+	err := fs.Parse([]string{"-float", "1.5"})
+	if err != nil {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(fv.Value, float64(1.5)) {
+		t.Fail()
+	}
+}
+
+func TestFloatHelp(t *testing.T) {
+	fv := flagvar.Float{BitSize: 64}
+	if !reflect.DeepEqual(fv.Help(), "a 64-bit float") {
+		t.Fail()
+	}
+	fv = flagvar.Float{BitSize: 32}
+	if !reflect.DeepEqual(fv.Help(), "a 32-bit float") {
+		t.Fail()
+	}
+}
+
+func TestFloatBitSize(t *testing.T) {
+	fv := flagvar.Float{BitSize: 64}
+	var fs flag.FlagSet
+	fs.Var(&fv, "float", "")
+
+	err := fs.Parse([]string{"-float", "1.234"})
+	if err != nil {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(fv.Value, float64(1.234)) {
+		t.Fail()
+	}
+}
+
+func TestFloatFail(t *testing.T) {
+	fv := flagvar.Float{}
+	var fs flag.FlagSet
+	fs.Var(&fv, "float", "")
+
+	err := fs.Parse([]string{"-float", "abc"})
+	if err == nil {
+		t.Fail()
+	}
+}
 func TestFloats(t *testing.T) {
 	fv := flagvar.Floats{}
 	var fs flag.FlagSet