aleksi / pointer

Go package pointer provides helpers to get pointers to values of built-in types.

pointer

Go package pointer provides helpers to convert between pointers and values of built-in (and, with Go 1.18+ generics, of any) types.

go get github.com/AlekSi/pointer

API is stable. Documentation.

package motivationalexample

import (
	"encoding/json"

	"github.com/AlekSi/pointer"
)

const (
	defaultName = "some name"
)

// Stuff contains optional fields.
type Stuff struct {
	Name    *string
	Comment *string
	Value   *int64
	Time    *time.Time
}

// SomeStuff makes some JSON-encoded stuff.
func SomeStuff() (data []byte, err error) {
	return json.Marshal(&Stuff{
		Name:    pointer.ToString(defaultName),                                   // can't say &defaultName
		Comment: pointer.ToString("not yet"),                                     // can't say &"not yet"
		Value:   pointer.ToInt64(42),                                             // can't say &42 or &int64(42)
		Time:    pointer.ToTime(time.Date(2014, 6, 25, 12, 24, 40, 0, time.UTC)), // can't say &time.Date(…)
	})
}

pointer's Issues

Add go.mod

Add documentation to all methods

That may sound redundant, but this helps with IDEs autocompletion.

Add methods to get values from the pointers

FromString(s *string) string {
    if s == nil {
        return ""
    }
    return *s
}

But maybe I can think of a better name.

Explain why this package exists

• golang/go#9097
• golang/go#45624
• https://pkg.go.dev/github.com/apache/thrift/lib/go/thrift#BoolPtr
• https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/aws?tab=doc#hdr-Value_and_Pointer_Conversion_Utilities
• https://pkg.go.dev/github.com/aws/aws-sdk-go/aws?tab=doc#hdr-Value_and_Pointer_Conversion_Utilities
• https://pkg.go.dev/github.com/aws/smithy-go/ptr
• https://pkg.go.dev/github.com/carlmjohnson/new
• https://pkg.go.dev/github.com/golang/protobuf/proto?tab=doc#Bool
• https://pkg.go.dev/github.com/google/go-github/v35/github#hdr-Creating_and_Updating_Resources
• https://pkg.go.dev/github.com/raksul/go-clickup/clickup#Bool
• https://pkg.go.dev/github.com/samber/lo#readme-toptr
• https://pkg.go.dev/github.com/siderolabs/go-pointer
• https://pkg.go.dev/github.com/stripe/stripe-go/v72#Bool
• https://pkg.go.dev/github.com/tsavola/pointer
• https://pkg.go.dev/go.uber.org/thriftrw/ptr
• https://pkg.go.dev/google.golang.org/protobuf/proto?tab=doc#hdr-Optional_scalar_constructors
• https://pkg.go.dev/k8s.io/utils/pointer
• etc

Changing semnatics of the functions

Hi, I find the pointer.ToX(v X) *X a bit confusing since by reading it (without looking at the parameter and return value) I would think it would turn a pointer of X to the value X, which it doesn't.
Maybe we could change it to ptr.OfX(v X) *X
Also, in a similar manner, I think pointer.GetX(v *X) X would be clearer as ptr.ToX(v *X) X
To summerize, I'm suggesting the following changes

pointer.ToX(v X) *X -> ptr.OfX(v X) *X
pointer.GetX(v *X) X -> ptr.ToX(v *X) X

I don't mind opening the PR, would you accept?