enumer/sql.go

77 lines
1.4 KiB
Go

package main
// Arguments to format are:
// [1]: type name
const valueMethod = `func (i %[1]s) Value() (driver.Value, error) {
return i.String(), nil
}
`
const scanMethod = `func (i *%[1]s) Scan(value interface{}) error {
if value == nil {
return nil
}
var str string
switch v := value.(type) {
case []byte:
str = string(v)
case string:
str = v
case fmt.Stringer:
str = v.String()
default:
return fmt.Errorf("invalid value of %[1]s: %%[1]T(%%[1]v)", value)
}
val, err := %[1]sString(str)
if err != nil {
return err
}
*i = val
return nil
}
`
const nullableImplementation = `
type Null%[1]s struct {
%[1]s %[1]s
Valid bool
}
func NewNull%[1]s(val interface{}) (x Null%[1]s) {
x.Scan(val) // yes, we ignore this error, it will just be an invalid value.
return
}
// Scan implements the Scanner interface.
func (x *Null%[1]s) Scan(value interface{}) (err error) {
if value == nil {
x.%[1]s, x.Valid = %[1]s(0), false
return
}
err = x.%[1]s.Scan(value)
x.Valid = (err == nil)
return
}
// Value implements the driver Valuer interface.
func (x Null%[1]s) Value() (driver.Value, error) {
if !x.Valid {
return nil, nil
}
return x.%[1]s.String(), nil
}
`
func (g *Generator) addValueAndScanMethod(typeName string) {
g.Printf("\n")
g.Printf(valueMethod, typeName)
g.Printf("\n\n")
g.Printf(scanMethod, typeName)
g.Printf("\n\n")
g.Printf(nullableImplementation, typeName)
}