lbry.go/null/float32.go
Alex Grintsvayg 094289d4cf
Add 'null/' from commit '109a79fb20ecd191f58366a452b38f7cf0ae1741'
Repo: github.com/lbryio/null.go

git-subtree-dir: null
git-subtree-mainline: 75e2abdeac
git-subtree-split: 109a79fb20
2018-02-22 13:05:01 -05:00

124 lines
2.5 KiB
Go

package null
import (
"bytes"
"database/sql/driver"
"encoding/json"
"strconv"
"gopkg.in/nullbio/null.v6/convert"
)
// Float32 is a nullable float32.
type Float32 struct {
Float32 float32
Valid bool
}
// NewFloat32 creates a new Float32
func NewFloat32(f float32, valid bool) Float32 {
return Float32{
Float32: f,
Valid: valid,
}
}
// Float32From creates a new Float32 that will always be valid.
func Float32From(f float32) Float32 {
return NewFloat32(f, true)
}
// Float32FromPtr creates a new Float32 that be null if f is nil.
func Float32FromPtr(f *float32) Float32 {
if f == nil {
return NewFloat32(0, false)
}
return NewFloat32(*f, true)
}
// UnmarshalJSON implements json.Unmarshaler.
func (f *Float32) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
f.Valid = false
f.Float32 = 0
return nil
}
var x float64
if err := json.Unmarshal(data, &x); err != nil {
return err
}
f.Float32 = float32(x)
f.Valid = true
return nil
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (f *Float32) UnmarshalText(text []byte) error {
if text == nil || len(text) == 0 {
f.Valid = false
return nil
}
var err error
res, err := strconv.ParseFloat(string(text), 32)
f.Valid = err == nil
if f.Valid {
f.Float32 = float32(res)
}
return err
}
// MarshalJSON implements json.Marshaler.
func (f Float32) MarshalJSON() ([]byte, error) {
if !f.Valid {
return NullBytes, nil
}
return []byte(strconv.FormatFloat(float64(f.Float32), 'f', -1, 32)), nil
}
// MarshalText implements encoding.TextMarshaler.
func (f Float32) MarshalText() ([]byte, error) {
if !f.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatFloat(float64(f.Float32), 'f', -1, 32)), nil
}
// SetValid changes this Float32's value and also sets it to be non-null.
func (f *Float32) SetValid(n float32) {
f.Float32 = n
f.Valid = true
}
// Ptr returns a pointer to this Float32's value, or a nil pointer if this Float32 is null.
func (f Float32) Ptr() *float32 {
if !f.Valid {
return nil
}
return &f.Float32
}
// IsNull returns true for invalid Float32s, for future omitempty support (Go 1.4?)
func (f Float32) IsNull() bool {
return !f.Valid
}
// Scan implements the Scanner interface.
func (f *Float32) Scan(value interface{}) error {
if value == nil {
f.Float32, f.Valid = 0, false
return nil
}
f.Valid = true
return convert.ConvertAssign(&f.Float32, value)
}
// Value implements the driver Valuer interface.
func (f Float32) Value() (driver.Value, error) {
if !f.Valid {
return nil, nil
}
return float64(f.Float32), nil
}