pointy

pointy

Simple helper functions to provide a shorthand to get a pointer to a variable holding a constant...because it's annoying when you have to do it hundreds of times in unit tests:

val := 42
pointerToVal := &val
// vs.
pointerToVal := pointy.Int(42)

New in release 1.1.0

Additional helper functions have been added to safely dereference pointers or return a fallback value:

val := 42
pointerToVal := &val
// then later in your code..
myVal := pointy.IntValue(pointerToVal, 99) // returns 42 (or 99 if pointerToVal was nil)

GoDoc

https://godoc.org/github.com/mwielbut/pointy

Installation

go get github.com/mwielbut/pointy

Example

package main

import (
	"fmt"

	"github.com/mwielbut/pointy"
)

func main() {
	foo := pointy.Int64(2018)
	fmt.Println("foo is a pointer to:", *foo)

	bar := pointy.String("point to me")
	fmt.Println("bar is a pointer to:", *bar)

	// get the value back out (new in v1.1.0)
	barVal := pointy.StringValue(bar, "empty!")
	fmt.Println("bar's value is:", barVal)
}

Available Functions

Bool(x bool) *bool BoolValue(p *bool, fallback bool) bool Byte(x byte) *byte ByteValue(p *byte, fallback byte) byte Complex128(x complex128) *complex128 Complex128Value(p *complex128, fallback complex128) complex128 Complex64(x complex64) *complex64 Complex64Value(p *complex64, fallback complex64) complex64 Float32(x float32) *float32 Float32Value(p *float32, fallback float32) float32 Float64(x float64) *float64 Float64Value(p *float64, fallback float64) float64 Int(x int) *int IntValue(p *int, fallback int) int Int8(x int8) *int8 Int8Value(p *int8, fallback int8) int8 Int16(x int16) *int16 Int16Value(p *int16, fallback int16) int16 Int32(x int32) *int32 Int32Value(p *int32, fallback int32) int32 Int64(x int64) *int64 Int64Value(p *int64, fallback int64) int64 Uint(x uint) *uint UintValue(p *uint, fallback uint) uint Uint8(x uint8) *uint8 Uint8Value(p *uint8, fallback uint8) uint8 Uint16(x uint16) *uint16 Uint16Value(p *uint16, fallback uint16) uint16 Uint32(x uint32) *uint32 Uint32Value(p *uint32, fallback uint32) uint32 Uint64(x uint64) *uint64 Uint64Value(p *uint64, fallback uint64) uint64 String(x string) *string StringValue(p *string, fallback string) string Rune(x rune) *rune RuneValue(p *rune, fallback rune) rune

Motivation

Creating pointers to literal constant values is useful, especially in unit tests. Go doesn't support simply using the address operator (&) to reference the location of e.g. value := &int64(42) so we're forced to create little workarounds. A common solution is to create a helper function:

func createInt64Pointer(x int64) *int64 {
    return &x
}
// now you can create a pointer to 42 inline
value := createInt64Pointer(42)

This package provides a library of these simple little helper functions for every native Go primitive.