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Scrub Out Unused Constants

Scrub Out Unused Constants

Low-level parsing in VB doesn’t come up every day. This routine demonstrates how to search a VB module for dead module-level constants with only a few lines of code. Reading the entire contents of a file into a string variable is key to this approach:

 Private Sub FindDeadConstants(ByVal _	PathAndFile As String)	Dim FileHandle As Integer	Dim FileContents As String	Dim PositionOfDeclaration As Long	Dim StartOfConstantName As Long	Dim EndOfConstantName As Long	Dim ConstantName As String	'open the file and read the contents 	'into a string variable:	FileHandle = FreeFile	Open PathAndFile For Binary Access _		Read As FileHandle	FileContents = _		Input$(LOF(FileHandle), _		FileHandle)	Close FileHandle	'loop through all the module-level 	'constants:	Do		PositionOfDeclaration = _			InStr(PositionOfDeclaration _			+ 1, FileContents, _			"Private Const ")		If PositionOfDeclaration > 0 Then			'we've found a constant:			StartOfConstantName = _				PositionOfDeclaration _				+ Len("Private Const ")			EndOfConstantName = _				InStr( _				StartOfConstantName, _				FileContents, " ")			ConstantName = _				Mid$(FileContents, _				StartOfConstantName, _					EndOfConstantName _					- StartOfConstantName)			'if the constant is not 			'referenced beyond its 			'declaration, then it's dead:			If InStr(EndOfConstantName, _				FileContents, _				ConstantName) = 0 Then				lstDeadConstants.AddItem _					ConstantName			End If		End If	Loop Until PositionOfDeclaration = 0End Sub
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