147 lines
3.5 KiB
Go
147 lines
3.5 KiB
Go
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package null
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import (
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"database/sql/driver"
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"encoding/json"
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"fmt"
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"reflect"
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"strconv"
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"gopkg.in/nullbio/null.v4/convert"
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)
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// NullFloat32 is a replica of sql.NullFloat64 for float32 types.
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type NullFloat32 struct {
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Float32 float32
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Valid bool
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}
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// Float32 is a nullable float32.
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// It does not consider zero values to be null.
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// It will decode to null, not zero, if null.
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type Float32 struct {
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NullFloat32
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}
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// NewFloat32 creates a new Float32
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func NewFloat32(f float32, valid bool) Float32 {
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return Float32{
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NullFloat32: NullFloat32{
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Float32: f,
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Valid: valid,
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},
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}
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}
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// Float32From creates a new Float32 that will always be valid.
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func Float32From(f float32) Float32 {
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return NewFloat32(f, true)
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}
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// Float32FromPtr creates a new Float32 that be null if f is nil.
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func Float32FromPtr(f *float32) Float32 {
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if f == nil {
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return NewFloat32(0, false)
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}
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return NewFloat32(*f, true)
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}
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// UnmarshalJSON implements json.Unmarshaler.
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// It supports number and null input.
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// 0 will not be considered a null Float32.
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// It also supports unmarshalling a sql.NullFloat32.
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func (f *Float32) UnmarshalJSON(data []byte) error {
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var err error
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var v interface{}
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if err = json.Unmarshal(data, &v); err != nil {
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return err
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}
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switch x := v.(type) {
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case float64:
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f.Float32 = float32(x)
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case map[string]interface{}:
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err = json.Unmarshal(data, &f.NullFloat32)
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case nil:
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f.Valid = false
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return nil
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default:
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err = fmt.Errorf("json: cannot unmarshal %v into Go value of type null.Float32", reflect.TypeOf(v).Name())
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}
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f.Valid = err == nil
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return err
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}
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// UnmarshalText implements encoding.TextUnmarshaler.
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// It will unmarshal to a null Float32 if the input is a blank or not an integer.
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// It will return an error if the input is not an integer, blank, or "null".
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func (f *Float32) UnmarshalText(text []byte) error {
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str := string(text)
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if str == "" || str == "null" {
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f.Valid = false
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return nil
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}
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var err error
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res, err := strconv.ParseFloat(string(text), 32)
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f.Valid = err == nil
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if f.Valid {
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f.Float32 = float32(res)
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}
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return err
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}
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// MarshalJSON implements json.Marshaler.
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// It will encode null if this Float32 is null.
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func (f Float32) MarshalJSON() ([]byte, error) {
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if !f.Valid {
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return []byte("null"), nil
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}
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return []byte(strconv.FormatFloat(float64(f.Float32), 'f', -1, 32)), nil
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}
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// MarshalText implements encoding.TextMarshaler.
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// It will encode a blank string if this Float32 is null.
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func (f Float32) MarshalText() ([]byte, error) {
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if !f.Valid {
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return []byte{}, nil
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}
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return []byte(strconv.FormatFloat(float64(f.Float32), 'f', -1, 32)), nil
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}
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// SetValid changes this Float32's value and also sets it to be non-null.
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func (f *Float32) SetValid(n float32) {
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f.Float32 = n
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f.Valid = true
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}
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// Ptr returns a pointer to this Float32's value, or a nil pointer if this Float32 is null.
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func (f Float32) Ptr() *float32 {
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if !f.Valid {
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return nil
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}
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return &f.Float32
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}
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// IsZero returns true for invalid Float32s, for future omitempty support (Go 1.4?)
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// A non-null Float32 with a 0 value will not be considered zero.
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func (f Float32) IsZero() bool {
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return !f.Valid
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}
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// Scan implements the Scanner interface.
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func (n *NullFloat32) Scan(value interface{}) error {
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if value == nil {
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n.Float32, n.Valid = 0, false
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return nil
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}
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n.Valid = true
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return convert.ConvertAssign(&n.Float32, value)
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}
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// Value implements the driver Valuer interface.
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func (n NullFloat32) Value() (driver.Value, error) {
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if !n.Valid {
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return nil, nil
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}
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return float64(n.Float32), nil
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}
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