IsMutable Property

Gets the value indicating whether the Grammar or any of its related instances can be modified.

Syntax

Visual Basic

'Declaration
 
Public ReadOnly Property IsMutable As Boolean

C#

public bool IsMutable {get;}

Remarks

A Grammar will become immutable the first time it is used to perform lexical or syntax analysis on a document.

If the Grammar is immutable, certain operations will cause an System.InvalidOperationException:

• Calling InitializeFrom
• Setting the NewLineSymbolName, StartSymbol, WhitespacePattern, or WhitespaceSymbolName
• Adding or removing items in the NonTerminalSymbols collection or a LexerState.Symbols collection.
• Adding or removing items in the LexerStates collection.
• Modifying a LexerState in in the Grammar
• Modifying a TerminalSymbol in the TerminalSymbols collection
• Modifying a NonTerminalSymbol in the NonTerminalSymbols collection
• Adding, removing, or modifying syntax rules of a NonTerminalSymbol belonging to the Grammar

Once a Grammar becomes immutable, it cannot become mutable again. However, a mutable copy of the Grammar can be created using the Clone method.

The Name can still be set when a Grammar is immutable because it does not affect how documents are parsed.

Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2