/Go-programming-examples

Simple repository which will be used to spam sourcecode which taught me how to use the Go programming language.

Primary LanguageGoMIT LicenseMIT

Notes:

Table of Contents

Introduction:

In this document one can find notes which I have taken during my studies of the Go programming language.

Brief summary about the history of Go:

  • Fall 2007: Start of the work on the golang

  • November 2009: release

  • March 2012: first stable release of Go with version 1

Use-cases:

Go allows programming on several layers of abstraction:

  • low-level:

    • embedding of C, assembler or system libraries

  • high-level:

    • grouping of components, which can be realized through design patterns

Packages in Go:

There are two types of packages in Go:

  • program packages: implement runnable programs

    • files which belong to program packages always have to start with the line package main

  • library packages: provide services to other parts of programs

    • can be distributed into multiple files

    • have a simple export mechanism

    • can be nested

    • can have an intialization part

  • The opportunity to split a package into multiple files allowed the separation of specification and implementation.

  • The relationships between packages are organized using the expressions import and export.

Imports:

Let abc be a package. All identifiers, which start with a Capital letter will be imported by using:

import "abc"

If one wants to imports multiple packages, this can be achieved using brackets and comma separated values inside of them. Identifiers which a small letter can not be accessed from the outside.

  • The import statement has to be right in the beginning of the file after the package …​ statement.

  • All imported identifiers will be called with their package name as prefix

Interfaces:

The syntactical form of a specification is expressed as an interface in Go. The following snippet shows an example of an interface:

package xyz

import "abc"

type Xyz interface {
    Abc
    X()
    Y() uint
    Z (b bool)
}

By looking at this interface from the perspective of a Java developer, one has to get confused at some point:

Abc, followed by two method signatures, followed by a single type, followed by an additional method signature, this has a specific meaning:

Abc is an interface imported from the package abc. Additionally the methods X() and Y() are inherited from this interface.

The method Z(b bool) is a new method, introduced by the interface Xyz.

Abstract data types:

Go does not offer specifications of abstract data types. By looking at the previously introduced syntax and rules one can still formulate them by the construction of a data type, instead of a data object, from which only a singleton can be created.

Constructors:

TODO: later

Literature and Sources: