Documentation
¶
Overview ¶
Package defaults provides support for setting default values in struct fields based on the value of the "default" struct tag.
Example ¶
package main
import (
"fmt"
"net/netip"
"github.com/mattdowdell/sandbox/internal/drivers/config/defaults"
)
type MyStruct struct {
Int int `default:"10"`
Bool bool `default:"true"`
String string `default:"hello"`
Child ChildStruct
}
type ChildStruct struct {
Float float64 `default:"1.2"`
Uint uint `default:"5"`
Addr netip.Addr `default:"127.0.0.1"`
}
func main() {
s := &MyStruct{}
if err := defaults.Set(s); err != nil {
panic(err)
}
fmt.Println(s)
}
Output: &{10 true hello {1.2 5 127.0.0.1}}
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Set ¶
Set sets the fields of a struct to the values in the "default" struct tag. The target argument must be a pointer to a struct.
By default, the following types are natively supported:
- int, int, int16, int32, int64 via strconv.ParseInt. - uint, uint8, uint16, uint32, uint64, uintptr via strconv.ParseUint. - float32, float64 via strconv.ParseFloat. - bool via strconv.ParseBool. - string - time.Duration via time.ParseDuration.
Integer default values can be specified in binary, octal, decimal, and hexadecimal by adding the appropriate prefix. Unparseable values result in an error being returned.
Structs within structs are also supported under the assumption they contain their own set of supported types.
Support for types other than those explicitly supported can implement encoding.TextUnmarshaler. This can also be implemented for type aliases of the supported types to override the default behaviour. Types that are not supported natively and do not implement encoding.TextUmarshaler result in an error being returned.
Defaults are not applied in the following circumstances:
- Private fields are skipped. - Fields with a non-zero value are skipped. - Empty values of the "default" struct tag are skipped.
Types ¶
This section is empty.
Source Files