119 lines
2.8 KiB
Go
119 lines
2.8 KiB
Go
|
package zero
|
||
|
|
|
||
|
|
import (
|
||
|
|
"database/sql"
|
||
|
|
"encoding/json"
|
||
|
|
"fmt"
|
||
|
|
"reflect"
|
||
|
|
"strconv"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Float is a nullable float64. Zero input will be considered null.
|
||
|
|
// JSON marshals to zero if null.
|
||
|
|
// Considered null to SQL if zero.
|
||
|
|
type Float struct {
|
||
|
|
sql.NullFloat64
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewFloat creates a new Float
|
||
|
|
func NewFloat(f float64, valid bool) Float {
|
||
|
|
return Float{
|
||
|
|
NullFloat64: sql.NullFloat64{
|
||
|
|
Float64: f,
|
||
|
|
Valid: valid,
|
||
|
|
},
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// FloatFrom creates a new Float that will be null if zero.
|
||
|
|
func FloatFrom(f float64) Float {
|
||
|
|
return NewFloat(f, f != 0)
|
||
|
|
}
|
||
|
|
|
||
|
|
// FloatFromPtr creates a new Float that be null if f is nil.
|
||
|
|
func FloatFromPtr(f *float64) Float {
|
||
|
|
if f == nil {
|
||
|
|
return NewFloat(0, false)
|
||
|
|
}
|
||
|
|
return NewFloat(*f, true)
|
||
|
|
}
|
||
|
|
|
||
|
|
// UnmarshalJSON implements json.Unmarshaler.
|
||
|
|
// It supports number and null input.
|
||
|
|
// 0 will be considered a null Float.
|
||
|
|
// It also supports unmarshalling a sql.NullFloat64.
|
||
|
|
func (f *Float) UnmarshalJSON(data []byte) error {
|
||
|
|
var err error
|
||
|
|
var v interface{}
|
||
|
|
if err = json.Unmarshal(data, &v); err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
switch x := v.(type) {
|
||
|
|
case float64:
|
||
|
|
f.Float64 = x
|
||
|
|
case map[string]interface{}:
|
||
|
|
err = json.Unmarshal(data, &f.NullFloat64)
|
||
|
|
case nil:
|
||
|
|
f.Valid = false
|
||
|
|
return nil
|
||
|
|
default:
|
||
|
|
err = fmt.Errorf("json: cannot unmarshal %v into Go value of type zero.Float", reflect.TypeOf(v).Name())
|
||
|
|
}
|
||
|
|
f.Valid = (err == nil) && (f.Float64 != 0)
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
|
||
|
|
// UnmarshalText implements encoding.TextUnmarshaler.
|
||
|
|
// It will unmarshal to a null Float if the input is a blank, zero, or not a float.
|
||
|
|
// It will return an error if the input is not a float, blank, or "null".
|
||
|
|
func (f *Float) UnmarshalText(text []byte) error {
|
||
|
|
str := string(text)
|
||
|
|
if str == "" || str == "null" {
|
||
|
|
f.Valid = false
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
var err error
|
||
|
|
f.Float64, err = strconv.ParseFloat(string(text), 64)
|
||
|
|
f.Valid = (err == nil) && (f.Float64 != 0)
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
|
||
|
|
// MarshalJSON implements json.Marshaler.
|
||
|
|
// It will encode null if this Float is null.
|
||
|
|
func (f Float) MarshalJSON() ([]byte, error) {
|
||
|
|
n := f.Float64
|
||
|
|
if !f.Valid {
|
||
|
|
n = 0
|
||
|
|
}
|
||
|
|
return []byte(strconv.FormatFloat(n, 'f', -1, 64)), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// MarshalText implements encoding.TextMarshaler.
|
||
|
|
// It will encode a zero if this Float is null.
|
||
|
|
func (f Float) MarshalText() ([]byte, error) {
|
||
|
|
n := f.Float64
|
||
|
|
if !f.Valid {
|
||
|
|
n = 0
|
||
|
|
}
|
||
|
|
return []byte(strconv.FormatFloat(n, 'f', -1, 64)), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetValid changes this Float's value and also sets it to be non-null.
|
||
|
|
func (f *Float) SetValid(v float64) {
|
||
|
|
f.Float64 = v
|
||
|
|
f.Valid = true
|
||
|
|
}
|
||
|
|
|
||
|
|
// Ptr returns a poFloater to this Float's value, or a nil poFloater if this Float is null.
|
||
|
|
func (f Float) Ptr() *float64 {
|
||
|
|
if !f.Valid {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
return &f.Float64
|
||
|
|
}
|
||
|
|
|
||
|
|
// IsZero returns true for null or zero Floats, for future omitempty support (Go 1.4?)
|
||
|
|
func (f Float) IsZero() bool {
|
||
|
|
return !f.Valid || f.Float64 == 0
|
||
|
|
}
|