Files

93 lines
1.7 KiB
Go

package bunpaginate
import (
"database/sql"
"database/sql/driver"
"encoding/json"
"fmt"
"math/big"
)
type BigInt big.Int
func (i *BigInt) MarshalJSON() ([]byte, error) {
return json.Marshal(i.ToMathBig())
}
func (i *BigInt) UnmarshalJSON(bytes []byte) error {
v, err := i.FromString(string(bytes))
if err != nil {
return err
}
*i = *v
return nil
}
func NewInt() *BigInt {
return new(BigInt)
}
func newBigint(x *big.Int) *BigInt {
return (*BigInt)(x)
}
// same as NewBigint()
func FromMathBig(x *big.Int) *BigInt {
return (*BigInt)(x)
}
func FromInt64(x int64) *BigInt {
return FromMathBig(big.NewInt(x))
}
func (i *BigInt) FromString(x string) (*BigInt, error) {
if x == "" {
return FromInt64(0), nil
}
a := big.NewInt(0)
b, ok := a.SetString(x, 10)
if !ok {
return nil, fmt.Errorf("cannot create Int from string")
}
return newBigint(b), nil
}
func (b *BigInt) Value() (driver.Value, error) {
return (*big.Int)(b).String(), nil
}
func (b *BigInt) Set(v *BigInt) *BigInt {
return (*BigInt)((*big.Int)(b).Set((*big.Int)(v)))
}
func (b *BigInt) Sub(x *BigInt, y *BigInt) *BigInt {
return (*BigInt)((*big.Int)(b).Sub((*big.Int)(x), (*big.Int)(y)))
}
func (b *BigInt) Scan(value interface{}) error {
var i sql.NullString
if err := i.Scan(value); err != nil {
return err
}
if _, ok := (*big.Int)(b).SetString(i.String, 10); ok {
return nil
}
return fmt.Errorf("Error converting type %T into Bigint", value)
}
func (b *BigInt) ToMathBig() *big.Int {
return (*big.Int)(b)
}
func (i *BigInt) Cmp(bottom *BigInt) int {
return (*big.Int)(i).Cmp((*big.Int)(bottom))
}
var _ json.Unmarshaler = (*BigInt)(nil)
var _ json.Marshaler = (*BigInt)(nil)