deepcopy

Documentation

Overview

Package deepcopy contains the implementation of the deepcopy plugin, which generates the deriveDeepCopy function.

The deriveDeepCopy function is a maintainable and fast way to implement fast copy functions.

When goderive walks over your code it is looking for a function that:

• was not implemented (or was previously derived) and
• has a predefined prefix.

In the following code the deriveDeepCopy function will be found, because it was not implemented and it has a prefix deriveDeepCopy. This prefix is configurable.

package main

import "sort"

type MyStruct struct {
	Int64     int64
	StringPtr *string
}

func (m *MyStruct) Clone() *MyStruct {
	if m == nil {
		return nil
	}
	n := &MyStruct{}
	deriveDeepCopy(n, m)
	return n
}

The initial type that is passed into deriveDeepCopy needs to have a reference type:

• pointer
• slice
• map

, otherwise we are not able to modify the input parameter and then what are you really copying, but as we go deeper we support most types.

Supported types:

• basic types
• named structs
• slices
• maps
• pointers to these types
• private fields of structs in external packages (using reflect and unsafe)
• and many more

Unsupported types:

• chan
• interface
• function
• unnamed structs, which are not comparable with the == operator

Example output can be found here: https://github.com/awalterschulze/goderive/tree/master/example/plugin/deepcopy

This plugin has been tested thoroughly.

Index

• func New(typesMap derive.TypesMap, p derive.Printer, deps map[string]derive.Dependency) derive.Generator
• func NewPlugin() derive.Plugin

Functions

func New

func New(typesMap derive.TypesMap, p derive.Printer, deps map[string]derive.Dependency) derive.Generator

New is a constructor for the deepcopy code generator. This generator should be reconstructed for each package.

func NewPlugin

func NewPlugin() derive.Plugin

NewPlugin creates a new deepcopy plugin. This function returns the plugin name, default prefix and a constructor for the deepcopy code generator.