Reserved Word - Reserved Words and Language Independence

Reserved Words and Language Independence

Microsoft’s .NET Common Language Infrastructure (CLI) specification allows code written in 40+ different programming languages to be combined together into a final product. Because of this, identifier/reserved word collisions can occur when code implemented in one language tries to execute code written in another language. For example, a Visual Basic.NET library may contain a class definition such as:

' Class Definition of This in Visual Basic.NET: Public Class this ' This class does something... End Class

If this is compiled and distributed as part of a toolbox, a C# programmer, wishing to define a variable of type “this” would encounter a problem: 'this' is a reserved word in C#. Thus, the following will not compile in C#:

// Using This Class in C#: this x = new this; // Won't compile!

A similar issue arises when accessing members, overriding virtual methods, and identifying namespaces.

In order to work around this issue, the specification allows the programmer to (in C#) place the at-sign before the identifier which forces it to be considered an identifier rather than a reserved word by the compiler.

// Using This Class in C#: @this x = new @this; // Will compile!

For consistency, this usage is also permitted in non-public settings such as local variables, parameter names, and private members.

Read more about this topic:  Reserved Word

Famous quotes containing the words reserved, words, language and/or independence:

    “This is that which we call Character,—a reserved force which acts directly by presence, and without means.”
    —Ralph Waldo Emerson (1803–1882)

    “It was only just words, words,—they meant nothing in the world to him, I might just as well have whistled. Words realize nothing, vivify nothing to you, unless you have suffered in your own person the thing which the words try to describe.”
    —Mark Twain [Samuel Langhorne Clemens] (1835–1910)

    “Theoretically, I grant you, there is no possibility of error in necessary reasoning. But to speak thus “theoretically,” is to use language in a Pickwickian sense. In practice, and in fact, mathematics is not exempt from that liability to error that affects everything that man does.”
    —Charles Sanders Peirce (1839–1914)

    “In a famous Middletown study of Muncie, Indiana, in 1924, mothers were asked to rank the qualities they most desire in their children. At the top of the list were conformity and strict obedience. More than fifty years later, when the Middletown survey was replicated, mothers placed autonomy and independence first. The healthiest parenting probably promotes a balance of these qualities in children.”
    —Richard Louv (20th century)