108 lines
3.2 KiB
Markdown
108 lines
3.2 KiB
Markdown
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# pointy
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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:
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```golang
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val := 42
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pointerToVal := &val
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// vs.
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pointerToVal := pointy.Int(42)
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```
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**New in release 1.1.0**
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Additional helper functions have been added to safely dereference pointers
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or return a fallback value:
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```golang
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val := 42
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pointerToVal := &val
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// then later in your code..
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myVal := pointy.IntValue(pointerToVal, 99) // returns 42 (or 99 if pointerToVal was nil)
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```
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## GoDoc
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https://godoc.org/github.com/mwielbut/pointy
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## Installation
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`go get github.com/mwielbut/pointy`
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## Example
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```golang
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package main
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import (
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"fmt"
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"github.com/mwielbut/pointy"
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)
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func main() {
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foo := pointy.Int64(2018)
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fmt.Println("foo is a pointer to:", *foo)
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bar := pointy.String("point to me")
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fmt.Println("bar is a pointer to:", *bar)
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// get the value back out (new in v1.1.0)
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barVal := pointy.StringValue(bar, "empty!")
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fmt.Println("bar's value is:", barVal)
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}
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```
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## Available Functions
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`Bool(x bool) *bool`
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`BoolValue(p *bool, fallback bool) bool`
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`Byte(x byte) *byte`
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`ByteValue(p *byte, fallback byte) byte `
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`Complex128(x complex128) *complex128`
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`Complex128Value(p *complex128, fallback complex128) complex128`
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`Complex64(x complex64) *complex64`
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`Complex64Value(p *complex64, fallback complex64) complex64`
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`Float32(x float32) *float32`
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`Float32Value(p *float32, fallback float32) float32`
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`Float64(x float64) *float64`
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`Float64Value(p *float64, fallback float64) float64`
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`Int(x int) *int`
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`IntValue(p *int, fallback int) int`
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`Int8(x int8) *int8`
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`Int8Value(p *int8, fallback int8) int8`
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`Int16(x int16) *int16`
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`Int16Value(p *int16, fallback int16) int16`
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`Int32(x int32) *int32`
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`Int32Value(p *int32, fallback int32) int32`
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`Int64(x int64) *int64`
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`Int64Value(p *int64, fallback int64) int64`
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`Uint(x uint) *uint`
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`UintValue(p *uint, fallback uint) uint`
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`Uint8(x uint8) *uint8`
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`Uint8Value(p *uint8, fallback uint8) uint8`
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`Uint16(x uint16) *uint16`
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`Uint16Value(p *uint16, fallback uint16) uint16`
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`Uint32(x uint32) *uint32`
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`Uint32Value(p *uint32, fallback uint32) uint32`
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`Uint64(x uint64) *uint64`
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`Uint64Value(p *uint64, fallback uint64) uint64`
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`String(x string) *string`
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`StringValue(p *string, fallback string) string`
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`Rune(x rune) *rune`
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`RuneValue(p *rune, fallback rune) rune`
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## Motivation
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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](https://stackoverflow.com/questions/35146286/find-address-of-constant-in-go/35146856#35146856) [little](https://stackoverflow.com/questions/34197248/how-can-i-store-reference-to-the-result-of-an-operation-in-go/34197367#34197367) [workarounds](https://stackoverflow.com/questions/30716354/how-do-i-do-a-literal-int64-in-go/30716481#30716481). A common solution is to create a helper function:
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```golang
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func createInt64Pointer(x int64) *int64 {
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return &x
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}
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// now you can create a pointer to 42 inline
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value := createInt64Pointer(42)
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```
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This package provides a library of these simple little helper functions for every native Go primitive.
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