Legacy Language Service Overview


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A language service provides editor support that lets you implement certain Visual Studio features. The Managed Package Framework (MPF) language service classes provide full support for frequently-used features and partial support for other features.

Fully Supported Features in the MPF

The MPF language service classes support the following features:

  • Syntax highlighting

  • Outlining

  • Commenting blocks of code

  • Brace matching

  • Code snippets

  • Custom document properties

  • IntelliSense parameter information

  • IntelliSense Quick Info

  • IntelliSense member completion

  • IntelliSense word completion

Partially Supported Features in the MPF

The MPF provides only partial support for the following features. This means that you must implement the methods that are called by the MPF.

  • Reformatting code. You supply the code that implements the reformatting.

  • Validating breakpoints by identifying valid code spans. You supply the code that identifies the code spans.

  • Supporting the debugger Autos window for displaying variables. You supply the code that determines what to show in the window.

  • Supporting the Navigation bar for quick navigation between types and members. You implement and return a helper class that populates the lists in the Navigation bar combo boxes.


You must complete several steps to implement the language service itself and the language service features that you want to support for your language. These steps are discussed in the following topics:

See Also

Implementing a Legacy Language Service
Legacy Language Service Extensibility