Introduction

This is a simple implementation of a context manager in Go, in the vein of Python's 'with' statement and C#'s 'using' statement, providing automatic disposal of objects, using the provided Dispose method. This package is still in version 0.1.0 so use with caution.

Example use

Imagine you are working with an imaginary Memoryfile struct which looks like this:

type MemoryFile struct {
	name string
	open bool
}

func (mf *MemoryFile) Open() {
	mf.open = true
	fmt.Printf("Opening %s\n", mf.name)
}

func (mf *MemoryFile) Close() {
	mf.open = false
	fmt.Printf("Closing %s\n", mf.name)
}

func (mf *MemoryFile) Dispose() {
	fmt.Printf("Disposing %s\n", mf.name)
	mf.Close()
}

func (mf *MemoryFile) Read() (string, error) {
	fmt.Printf("Reading %s\n", mf.name)
	return mf.name, nil
}

As you can see, we have put in a Dispose() method, the file gets closed. You can use with our resource manager as follows:

import (
	"fmt"
	contextmanager "github.com/snoekiede/gocontextmanager"
)

func main() {
	mf := &MemoryFile{name: "test.txt"}
	text := "Nothing read"
	text, err := WithContext(mf, func(a *MemoryFile) (string, error) {
		a.Open()
		result, err := a.Read()
		return result, err
	}, func(element *MemoryFile) {
		element.Dispose()
	})
	if err != nil {
		fmt.Printf("Error %s\n", err)
	}
	fmt.Printf("Read %s\n", text)
}

Version list

• 0.1.0 initial commit