Add *big.Float support.

.travis.yml

@@ -1,5 +1,7 @@
 language: go
 go:
+  - 1.4.2
+  - 1.5
   - tip
 before_install:
   - go get github.com/axw/gocov/gocov

accounting15.go

@@ -0,0 +1,15 @@
+// +build go1.5
+
+package accounting
+
+import (
+	"math/big"
+)
+
+// FormatMoneyBigFloat only supports *big.Float value. It is faster than FormatMoney,
+// because it does not do any runtime type evaluation.
+func (accounting *Accounting) FormatMoneyBigFloat(value *big.Float) string {
+	accounting.init()
+	formattedNumber := FormatNumberBigFloat(value, accounting.Precision, accounting.Thousand, accounting.Decimal)
+	return accounting.formatMoneyString(formattedNumber)
+}

accounting15_test.go

@@ -0,0 +1,26 @@
+// +build go1.5
+
+package accounting
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestFormatMoneyBigFloat(t *testing.T) {
+	accounting := Accounting{Symbol: "$", Precision: 2}
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(123456789.213123)), "$123,456,789.21")
+
+	accounting = Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(4999.99)), "€4.999,99")
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(-4999.99)), "€-4.999,99")
+
+	accounting = Accounting{Symbol: "£ ", Precision: 0}
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(-500000.0)), "£ -500,000")
+
+	accounting = Accounting{Symbol: "GBP", Precision: 0,
+		Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(1000000.0)), "GBP 1,000,000")
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(-5000.0)), "GBP (5,000)")
+	AssertEqual(t, accounting.FormatMoneyBigFloat(big.NewFloat(0.0)), "GBP --")
+}

accounting_test.go

@@ -3,6 +3,8 @@ package accounting
 import (
 	"math/big"
 	"testing"
+	"runtime"
+	"fmt"
 )
 
 func AssertEqual(t *testing.T, x, y string) {
@@ -11,6 +13,10 @@ func AssertEqual(t *testing.T, x, y string) {
 	}
 }
 
+func init() {
+	fmt.Printf("version: %s", runtime.Version())
+}
+
 func TestFormatMoney(t *testing.T) {
 	accounting := Accounting{Symbol: "$", Precision: 2}
 	AssertEqual(t, accounting.FormatMoney(123456789.213123), "$123,456,789.21")

formatnumber15.go

@@ -0,0 +1,13 @@
+// +build go1.5
+
+package accounting
+
+import (
+	"math/big"
+)
+
+// FormatNumberBigFloat only supports *big.Float value.
+// It is faster than FormatNumber, because it does not do any runtime type evaluation.
+func FormatNumberBigFloat(x *big.Float, precision int, thousand string, decimal string) string {
+	return formatNumberString(x.Text('f', precision), precision, thousand, decimal)
+}

formatnumber15_test.go

@@ -0,0 +1,17 @@
+// +build go1.5
+
+package accounting
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestFormatNumberBigFloat(t *testing.T) {
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(123456789.213123), 3, ",", "."), "123,456,789.213")
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-12345.123123), 5, ",", "."), "-12,345.12312")
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-1234.123123), 5, ",", "."), "-1,234.12312")
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-123.123123), 5, ",", "."), "-123.12312")
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-12.123123), 5, ",", "."), "-12.12312")
+	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-1.123123), 5, ",", "."), "-1.12312")
+}