IsLookaheadNegative Property

Gets or sets the value indicating whether the LookaheadPattern should be used to perform a negative or positive lookahead.

Syntax

Visual Basic

'Declaration
 
Public Property IsLookaheadNegative As Boolean

C#

public bool IsLookaheadNegative {get; set;}

Exceptions

Exception	Description
System.InvalidOperationException	Occurs when the IsMutable value of the owning Grammar is False.

Remarks

The LookaheadPattern is a regular expression pattern which the lexical analyzer will try to match using the text following a token associated with this TerminalSymbol. IsLookaheadNegative indicates whether the token should be used based on whether the match is found or not. If IsLookaheadNegative is True, the token will only be used if the LookaheadPattern cannot match the text after the token. If False, the token will only be used if the LookaheadPattern can match the text after the token.

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