The allocate's intro from cjrd

allocate's Introduction

Allocate

Allocate provides functions for allocating golang structs so that pointer fields are pointers to zero'd values instead of nil. See the godoc's for more information: https://godoc.org/github.com/cjrd/allocate

Brief Example

package main

import (
    "fmt"
    "github.com/cjrd/allocate"
)

type TopLevelStruct struct {
    MyEmbeddedStruct *EmbeddedStruct
}

type EmbeddedStruct struct {
    SomeString string
    SomeInt int
}

func main() {
    topStruct := new(TopLevelStruct)
    fmt.Printf("before using allocate.Zero: %v\n", topStruct)

    allocate.Zero(&topStruct)
    fmt.Printf("post allocate.Zero: %v\n", topStruct)
    fmt.Printf("topStruct.MyEmbeddedStruct.SomeInt==%d\n", topStruct.MyEmbeddedStruct.SomeInt)
    // Note that panics would occur by executing `*topStruct.MyEmbeddedStruct` or
    //`topStruct.MyEmbeddedStruct.SomeInt`
}

# OUTPUT
before using allocate.Zero: &{<nil>}
post allocate.Zero: &{0x8201d2400}
topStruct.MyEmbeddedStruct.SomeInt == 0

Use Cases

Initializing structures that contain any type of pointer fields, including recursive struct fields
Preventing panics by ensuring that all fields of a struct are initialized
Initializing golang protobuf struct (the golang protobuf makes heavy use of pointers to embedded structs that contain pointers to embedded structs, ad infinitum)
Initializing structs for black box testing (see also https://golang.org/pkg/testing/quick/)

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