Language Integrated Query: Difference between revisions

Revision as of 19:23, 10 July 2020

Revision as of 21:07, 3 December 2020

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===Language extensions===

While LINQ is primarily implemented as a [[library (computing)|library]] for .NET Framework 3.5, it also defines optional language extensions that make queries a first-class [[language construct]] and provide [[syntactic sugar]] for writing queries. These language extensions have initially been implemented in [[C Sharp (programming language)|C#]] 3.0, [[VB.NET|VB 9.0]], [[F Sharp (programming language)|F#]]<ref name="linq">{{cite web|title=Query Expressions (F#)|url=https://docs.microsoft.com/en-gb/dotnet/fsharp/language-reference/query-expressions|last=|first=|date=|website=Microsoft Docs|url-status=live|archive-url=|archive-date=|accessdate=2012-12-19}}</ref> and [[Oxygene (programming language)|Oxygene]], with other languages like [[Nemerle]] having announced preliminary support. The language extensions include:<ref name="linq1">{{cite web | url = http://msdn.microsoft.com/en-us/library/bb397921.aspx | title = LINQ Framework | accessdate = 2007-11-30}}</ref>

*Query syntax: A language is free to choose a query syntax that it will recognize natively. These language keywords must be translated by the compiler to appropriate LINQ method calls.

*Implicitly typed variables: This enhancement allows variables to be declared without specifying their types. The languages C# 3.0 and Oxygene declare them with the <code>var</code> keyword. In VB9.0, the <code>Dim</code> keyword without type declaration accomplishes the same. Such objects are still [[strong typing|strongly typed]]; for these objects the compiler infers the types of variables via [[type inference]], which allows the results of the queries to be specified and defined without declaring the type of the intermediate variables.