![]() ![]() When the compiler's behavior is at odds with a documented behavior in the language specification, fixing the compiler behavior to match the documented behavior may be necessary. Help will be provided to upgrade projects from previous versions and escape any new keywords.Ĭompiler bugs. Reasonable efforts will be made to choose keywords that minimize the possibility of collision with users' identifiers and to use existing keywords where it makes sense. Introducing new keywords may be necessary when introducing new language features. However, because many developers compile with "treat warnings as errors" turned on, extra care must be taken when introducing warnings. Introducing a new warning is not, per se, a compatibility break. However, there may be situations where the need for a compatibility break may outweigh the cost it may impose on programmers. In an ideal world, compatibility would be 100% between the existing version of Visual Basic and all future versions of Visual Basic. NET Framework are covered by a separate versioning and compatibility policy outside the scope of this document. ![]() NET Framework classes included as a part of the Microsoft.VisualBasic namespace (and sub-namespaces). The term language, when used in this context, refers only to the syntactic and semantic aspects of the Visual Basic language itself and does not include any. ![]() The following policy governs changes to the Visual Basic language between versions. As such, compatibility between versions must be preserved except when the benefit to language consumers is of a clear and overwhelming nature. If a newer version of a language does not accept the same code as a previous version of the language, or interprets it differently than the previous version, then a burden can be placed on a programmer when upgrading his code from one version of the language to another. CompatibilityĪn important feature of a programming language is compatibility between different versions of the language. Line breaks and indentation may be added for readability and are not part of the production. A token will not match if it contains mixed half-width and full-width characters. Visual Basic is also width insensitive when matching terminals, allowing full-width Unicode characters to match their half-width Unicode equivalents, but only on a whole-token basis. Terminals that are printable elements of the ASCII character set are represented by their corresponding ASCII characters. For simplicity, all terminals will be given in standard casing, but any casing will match them. Ĭase is unimportant in Visual Basic programs. The grammars in this specification are written in ANTLR format - see. There are also several secondary grammars used for preprocessing operations like conditional compilation. The lexical grammar defines how characters can be combined to form tokens the syntactic grammar defines how the tokens can be combined to form Visual Basic programs. This specification describes two grammars: a lexical grammar and a syntactic grammar. It is meant to be a complete language description rather than a language tutorial or a user's reference manual. This document describes the Visual Basic language. This is useful when building production applications in which speed of execution and execution correctness is important. This guarantees maximum performance and helps ensure that type conversions are correct. The Visual Basic programming language also provides strongly typed semantics that performs all type checking at compile-time and disallows run-time binding of method calls. This is useful when building prototypes or other programs in which speed of development is more important than execution speed. This includes not only type checking of conversions but also of method calls, meaning that the binding of a method call can be deferred until run-time. Loose typing defers much of the burden of type checking until a program is already running. The Visual Basic programming language can be either a strongly typed or a loosely typed language. Extraneous or unneeded syntax is generally allowed but not required. Wherever possible, meaningful words or phrases are used instead of abbreviations, acronyms, or special characters. The Visual Basic programming language has a syntax that is similar to English, which promotes the clarity and readability of Visual Basic code. Although it is designed to be an approachable and easy-to-learn language, it is also powerful enough to satisfy the needs of experienced programmers. ![]() The Microsoft® Visual Basic® programming language is a high-level programming language for the Microsoft. ![]()
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