xml-parser.txt

'-------------------------------------------------------------------------------
'
' XML DOM-like parser implemented in VSL (Viz3 scripting language)
'
' Implemented by Rune Bjerke [rune ÄT never DÖT no] (rune @ Vizrt forums)
'
' Version 1.0 - 2015-09-25
'
' Copyright © never.no - but you're free to reuse this as long as you
' leave this notice in, or say hi on the Vizrt forums :P
'
' Provided as-is, with no warranties as to if it works properly or not.
' You're to blame if you use this.
'
' See example usage in (test.txt), but basically:
'
' 1) use ParseXml(xml, ignoreWhitespace, ignoreAdvanced) to parse the XML
' 2) use FindElement() or FindElements() to find stuff/navigate
' 3) use FlattenElement() to get text values
'
' Not tested on a very high number of XML file samples, but should deal with
' the basics.
'
' Does not really support:
'
' - <!DOCTYPE ..> parsing (but somewhat gracefully deals with it)
' - Name spaces (.Name will be e.g. ns:foo)
'
'-------------------------------------------------------------------------------

structure XmlNode

	' This will be either:
	' 'document'
	' 'element'
	' 'text'
	' 'whitespace'
	' 'cdata'
	' 'comment'
	' 'processing-instruction'
	' 'doctype-unparsed'
	' 'doctype-unparsed-internal'
	' 'error'
	Type as String
	
	' Element name for Type=element
	Name as String
	
	' Actual value for Type=text|cdata|whitespace|comment (Also set for doctype-*)
	Value as String
	
	' Attributes for Type=element|processing-instruction
	Attributes as StringMap
	
	' Any child nodes
	Children as Array[XmlNode]
	
end structure

function ParseXml(byval xml as String, ignoreWhitespace as boolean, ignoreAdvanced as boolean) as XmlNode

	dim document as XmlNode
	document.Type = "document"
	ParseNextXmlNode(xml, document, ignoreWhitespace, ignoreAdvanced)
	ParseXml = document

end function

sub ParseNextXmlNode(byref xml as String, byref node as XmlNode, ignoreWhitespace as boolean, ignoreAdvanced as boolean)

	dim length as integer = len(xml)
	dim i as integer = 1
	dim iterateEscape as integer = 0

	do while (iterateEscape < 99999 and length > 0) 

		'println "-----"
		'println ""
		'println "xml is: " & xml
		'println ""

		dim j as integer = xml.Find("<")
		'println "< @ " & j

		if (j > -1) then
		
			if (j > 0) then
				' we have some text or white space content
				dim t as string = xml.GetSubstring(0, j)
				xml.Erase(0, j)
				'println "found text(" & j & ") = " & t
				
				dim tx as XmlNode
				tx.Type = "text"
				tx.Value = XmlUnescape(t)
				if (IsWhitespace(t)) then
					tx.Type = "whitespace"
					if not ignoreWhitespace	then node.Children.Push(tx)				
				else
					node.Children.Push(tx)
				end if

			end if
			
			dim ch as string = xml.GetChar(1)

			if (ch = "!") then
			
				if (xml.GetSubstring(0, 9) = "<![CDATA[") then
					' <![CDATA[ .. ]]>
					dim k as integer = xml.Find("]]>")
					dim t as string = xml.GetSubstring(9, k-9)
					xml.Erase(0, k+3)
					'println "found cdata(" & k & ") = " & t
					
					dim cd as XmlNode
					cd.Type = "cdata"
					cd.Value = t
					node.Children.Push(cd)
					
				elseif	(xml.GetSubstring(0, 4) = "<!--") then
				
					' <!-- .. -->
					dim k as integer = xml.Find("-->")
					dim t as string = xml.GetSubstring(4, k-4)
					xml.Erase(0, k+3)
					'println "found comment(" & k & ") = " & t
					
					dim c as XmlNode
					c.Type = "comment"
					c.Value = XmlUnescape(t)
					if not ignoreAdvanced then node.Children.Push(c)
					
				elseif	(xml.GetSubstring(0, 9) = "<!DOCTYPE") then

					' this is all very hack-ish, but we don't support this anyhow..

					' either <!DOCTYPE blah XXX "YYY" "URL" [ .. ]>
					' or <!DOCTYPE blah XXX "YYY" "URL">				
					
					dim dt as XmlNode

					dim e as integer = xml.Find(">") ' end tag
					dim o as integer = xml.Find("[") ' open inline
					dim c as integer = xml.Find("]>") ' close inline
					
					dim t as string
					if e > o and c > o then
						' case 1, most likely from an inline <!ENTITY..>
						t = xml.GetSubstring(0, c+2)
						xml.Erase(0, c + 2)
						dt.Type = "doctype-unparsed-internal"
					else
						' case 2, no inline.. [ is from later somewhere
						t = xml.GetSubstring(0, e+1)
						xml.Erase(0, e + 1)
						dt.Type = "doctype-unparsed"
					end if
					
					if not ignoreAdvanced then
						dt.Value = t
						node.Children.Push(dt)
					end if
					
				else
				
					' SOME ERROR OCCURRED AS WE DONT KNOW HOW TO DEAL WITH THIS
					dim e as XmlNode
					e.Type = "error"
					e.Value = "Don't know how to parse: " & xml
					xml = ""
					node.Children.Push(e)
					Exit Sub
				
				end if
				
			else
				' <element>, </element> or <element /> or <?pi?>
				dim k as integer = xml.Find(">")
				dim t as string = xml.GetSubstring(1, k - 1)
				xml.Erase(0, k + 1)
				
				dim isPi as boolean = false
				dim isOpen as boolean = false
				dim isClose as boolean = false
				      
				if ch = "?" then
					' <?pi .. ?>
					isPi = true
					isOpen = true
					isClose = true
					t = t.GetSubstring(1, Len(t)-2)
				elseif ch = "/" then
					' </endTag>
					isClose = true
					t.Erase(0, 1)
				elseif t.Right(1) = "/" then
					' <containedTag .. />
					isOpen = true
					isClose = true
					t.Erase(t.Length - 1, 1)
				else
					' <startTag ..>
					isOpen = true
				end if
				
				t.Trim()

				'println "found element(" & k & ")(open: " & isOpen & ", close: " & isClose & ", pi: " & isPi & ") = " & t
				
				dim n as XmlNode
				if isPi then
					n.Type = "processing-instruction"
				else
					n.Type = "element"
				end if
				'n.Value = t
				
				if isOpen then

					' parse the tag body
					dim el as string
					dim attrs as string
					ParseXmlTagBody(t, el, attrs)
					n.Name = el
				
					' parse attributes
					n.Attributes = ParseXmlAttributes(attrs)
				
					' recurse?
					if not isClose then
						ParseNextXmlNode(xml, n, ignoreWhitespace, ignoreAdvanced)
					end if
					
					if not (ignoreAdvanced and n.Type <> "element") then
						node.Children.Push(n)
					end if
					
				elseif not isOpen and isClose then
					Exit Sub
				end if

			end if
		else
			' trailing text
			dim t as string = xml
			'println "found text(" & j & ") = " & t
			xml = ""
			
			dim tx as XmlNode
			tx.Type = "text"
			tx.Value = XmlUnescape(t)
			if (IsWhitespace(t)) then
				tx.Type = "whitespace"
				if not ignoreWhitespace	then node.Children.Push(tx)				
			else
				node.Children.Push(tx)
			end if
	
		end if

		length = Len(xml)
		iterateEscape = iterateEscape + 1

	loop

end sub

function IsWhitespace(t as string) as Boolean

	'if ch = " " or ch = "\r" or ch = "\n" or ch = "\t"
	t.Trim()
	
	if t.Length = 0 then
		IsWhitespace = true
	else
		IsWhitespace = false
	end if

end function

sub ParseXmlTagBody(byval body as string, byref element as string, byref attrs as string)

	element = ""
	attrs = ""

	dim i as integer	
	dim endPos as integer = -1
	
	body.Trim()
	
	for i = 0 to body.Length - 1
		dim ch as string = body.GetChar(i)
		if IsWhitespace(ch) then
			endPos = i
			exit for
		end if
	next

	if (endPos > 0) then
	
		element = body.GetSubstring(0, endPos)
		element.Trim()
		
		attrs = body.GetSubstring(endPos, body.Length - endPos)
		attrs.Trim()
		
	else
	
		element = body
		
	end if

end sub

function ParseXmlAttributes(byval body as string) as StringMap

	dim i as integer
	dim j as integer
	
	'println "\n\r-------parsing attributes: [" & body & "]"
	
	do while body.Length > 0

		body.Trim()
		'println "body is [" & body & "]"
	
		' find the = char that ends the attribute name
		j = body.Find("=")
		if j < 0 then Exit Do ' stop parsing if not found
		
		' extract the attribute name and erase all characters up till and including the =
		dim key as string = body.GetSubstring(0, j)
		key.Trim()
		body.Erase(0, j + 1)
		'println "  found key=[" & key & "] @ " & j
		'println "body is [" & body & "]"
		
		' find the " character that starts the attribute value
		j = body.Find("\"")
		if j < 0 then Exit Do ' stop parsing if not found
		
		' remove all up till and including the "
		body.Erase(0, j+1)
		
		' find the ending " character
		j = body.Find("\"")
		if j < 0 then Exit Do ' stop parsing if not found

		' extract the attribute value and erase all characters up till and including the ending "
		dim value as string = body.GetSubstring(0, j)
		body.Erase(0, j+1)
	
		' add attribute
		ParseXmlAttributes[key] = XmlUnescape(value)
		
	loop

end function

function DumpXmlNode(byref node as XmlNode, indent as string) as string

	dim out as string = ""
	dim CRLF as string = chr(13) & chr(10)
	
	if (node.Type = "cdata") or (node.Type = "text") or (node.Type = "whitespace") or (node.Type = "comment") or (node.Type = "error") then
		out = out & indent & "[" & node.Type & "] = '" & node.Value & "'" & CRLF
	else
		out = out & indent & "[" & node.Type & "](" & node.Name & ")"
		dim keys as array[string]
		node.Attributes.GetKeys(keys)
		for i = keys.LBound to keys.UBound			
			out = out & " @" & keys[i] & "='" & node.Attributes[keys[i]] & "'"
		next
		out = out & CRLF
	end if
	
	dim nindent = indent & "  "
	for i = node.Children.LBound to node.Children.UBound
		out = out & DumpXmlNode(node.Children[i], nindent)
	next
	DumpXmlNode = out

end function

function XmlUnescape(s as string) as string

	dim v as string = ""
	dim i as integer
	do while s.Length > 0
		dim j as integer = s.Find("&")
		if (j < 0) then
			v = v & s
			Exit Do
		else
			v = v & s.GetSubstring(0, j)
			s.Erase(0, j)
			j = s.Find(";")
			if (j < 0) then
				' ERROR: let's just leave it as-is
				v = v & "&" & s
				Exit Do
			else
				dim e as string = s.GetSubstring(1, j-1)
				s.Erase(0, j+1)
				v = v & TranslateXmlEntity(e)
			end if
		end if
	loop
	XmlUnescape = v	
	
end function

dim XmlEntities as StringMap
dim IsXmlEntitiesInitialized as Boolean = false

sub InitializeXmlEntities()

	' This list is not complete, and is probably based more on HTML
	' than on actual XML entities..
	
	XmlEntities["quot"] = "\""
	XmlEntities["amp"] = "&"
	XmlEntities["apos"] = "'"
	XmlEntities["lt"] = "<"
	XmlEntities["gt"] = ">"
	XmlEntities["nbsp"] = ""
	XmlEntities["iexcl"] = "¡"
	XmlEntities["cent"] = "¢"
	XmlEntities["pound"] = "£"
	XmlEntities["curren"] = "¤"
	XmlEntities["yen"] = "¥"
	XmlEntities["brvbar"] = "¦"
	XmlEntities["sect"] = "§"
	XmlEntities["uml"] = "¨"
	XmlEntities["copy"] = "©"
	XmlEntities["ordf"] = "ª"
	XmlEntities["laquo"] = "«"
	XmlEntities["not"] = "¬"
	XmlEntities["shy"] = ""
	XmlEntities["reg"] = "®"
	XmlEntities["macr"] = "¯"
	XmlEntities["deg"] = "°"
	XmlEntities["plusmn"] = "±"
	XmlEntities["sup2"] = "²"
	XmlEntities["sup3"] = "³"
	XmlEntities["acute"] = "´"
	XmlEntities["micro"] = "µ"
	XmlEntities["para"] = "¶"
	XmlEntities["middot"] = "·"
	XmlEntities["cedil"] = "¸"
	XmlEntities["sup1"] = "¹"
	XmlEntities["ordm"] = "º"
	XmlEntities["raquo"] = "»"
	XmlEntities["frac14"] = "¼"
	XmlEntities["frac12"] = "½"
	XmlEntities["frac34"] = "¾"
	XmlEntities["iquest"] = "¿"
	XmlEntities["Agrave"] = "À"
	XmlEntities["Aacute"] = "Á"
	XmlEntities["Acirc"] = "Â"
	XmlEntities["Atilde"] = "Ã"
	XmlEntities["Auml"] = "Ä"
	XmlEntities["Aring"] = "Å"
	XmlEntities["AElig"] = "Æ"
	XmlEntities["Ccedil"] = "Ç"
	XmlEntities["Egrave"] = "È"
	XmlEntities["Eacute"] = "É"
	XmlEntities["Ecirc"] = "Ê"
	XmlEntities["Euml"] = "Ë"
	XmlEntities["Igrave"] = "Ì"
	XmlEntities["Iacute"] = "Í"
	XmlEntities["Icirc"] = "Î"
	XmlEntities["Iuml"] = "Ï"
	XmlEntities["ETH"] = "Ð"
	XmlEntities["Ntilde"] = "Ñ"
	XmlEntities["Ograve"] = "Ò"
	XmlEntities["Oacute"] = "Ó"
	XmlEntities["Ocirc"] = "Ô"
	XmlEntities["Otilde"] = "Õ"
	XmlEntities["Ouml"] = "Ö"
	XmlEntities["times"] = "×"
	XmlEntities["Oslash"] = "Ø"
	XmlEntities["Ugrave"] = "Ù"
	XmlEntities["Uacute"] = "Ú"
	XmlEntities["Ucirc"] = "Û"
	XmlEntities["Uuml"] = "Ü"
	XmlEntities["Yacute"] = "Ý"
	XmlEntities["THORN"] = "Þ"
	XmlEntities["szlig"] = "ß"
	XmlEntities["agrave"] = "à"
	XmlEntities["aacute"] = "á"
	XmlEntities["acirc"] = "â"
	XmlEntities["atilde"] = "ã"
	XmlEntities["auml"] = "ä"
	XmlEntities["aring"] = "å"
	XmlEntities["aelig"] = "æ"
	XmlEntities["ccedil"] = "ç"
	XmlEntities["egrave"] = "è"
	XmlEntities["eacute"] = "é"
	XmlEntities["ecirc"] = "ê"
	XmlEntities["euml"] = "ë"
	XmlEntities["igrave"] = "ì"
	XmlEntities["iacute"] = "í"
	XmlEntities["icirc"] = "î"
	XmlEntities["iuml"] = "ï"
	XmlEntities["eth"] = "ð"
	XmlEntities["ntilde"] = "ñ"
	XmlEntities["ograve"] = "ò"
	XmlEntities["oacute"] = "ó"
	XmlEntities["ocirc"] = "ô"
	XmlEntities["otilde"] = "õ"
	XmlEntities["ouml"] = "ö"
	XmlEntities["divide"] = "÷"
	XmlEntities["oslash"] = "ø"
	XmlEntities["ugrave"] = "ù"
	XmlEntities["uacute"] = "ú"
	XmlEntities["ucirc"] = "û"
	XmlEntities["uuml"] = "ü"
	XmlEntities["yacute"] = "ý"
	XmlEntities["thorn"] = "þ"
	XmlEntities["yuml"] = "ÿ"
	XmlEntities["OElig"] = "Œ"
	XmlEntities["oelig"] = "œ"
	XmlEntities["Scaron"] = "Š"
	XmlEntities["scaron"] = "š"
	XmlEntities["Yuml"] = "Ÿ"
	XmlEntities["fnof"] = "ƒ"
	XmlEntities["circ"] = "ˆ"
	XmlEntities["tilde˜"] = ""
	XmlEntities["Alpha"] = "?"
	XmlEntities["Beta"] = "?"
	XmlEntities["Gamma"] = "G"
	XmlEntities["Delta"] = "?"
	XmlEntities["Epsilon"] = "?"
	XmlEntities["Zeta"] = "?"
	XmlEntities["Eta"] = "?"
	XmlEntities["Theta"] = "T"
	XmlEntities["Iota"] = "?"
	XmlEntities["Kappa"] = "?"
	XmlEntities["Lambda"] = "?"
	XmlEntities["Mu"] = "?"
	XmlEntities["Nu"] = "?"
	XmlEntities["Xi"] = "?"
	XmlEntities["Omicron"] = "?"
	XmlEntities["Pi"] = "?"
	XmlEntities["Rho"] = "?"
	XmlEntities["Sigma"] = "S"
	XmlEntities["Tau"] = "?"
	XmlEntities["Upsilon"] = "?"
	XmlEntities["Phi"] = "F"
	XmlEntities["Chi"] = "?"
	XmlEntities["Psi"] = "?"
	XmlEntities["Omega"] = "O"
	XmlEntities["alpha"] = "a"
	XmlEntities["beta"] = "ß"
	XmlEntities["gamma"] = "?"
	XmlEntities["delta"] = "d"
	XmlEntities["epsilon"] = "e"
	XmlEntities["zeta"] = "?"
	XmlEntities["eta"] = "?"
	XmlEntities["theta"] = "?"
	XmlEntities["iota"] = "?"
	XmlEntities["kappa"] = "?"
	XmlEntities["lambda"] = "?"
	XmlEntities["mu"] = "µ"
	XmlEntities["nu"] = "?"
	XmlEntities["xi"] = "?"
	XmlEntities["omicron"] = "?"
	XmlEntities["pi"] = "p"
	XmlEntities["rho"] = "?"
	XmlEntities["sigmaf"] = "?"
	XmlEntities["sigma"] = "s"
	XmlEntities["tau"] = "t"
	XmlEntities["upsilon"] = "?"
	XmlEntities["phi"] = "f"
	XmlEntities["chi"] = "?"
	XmlEntities["psi"] = "?"
	XmlEntities["omega"] = "?"
	XmlEntities["thetasym"] = "?"
	XmlEntities["upsih"] = "?"
	XmlEntities["piv"] = "?"
	XmlEntities["ensp"] = " "
	XmlEntities["emsp"] = " "
	XmlEntities["thinsp"] = "?"
	XmlEntities["zwnj"] = ""
	XmlEntities["zwj"] = ""
	XmlEntities["ndash"] = "–"
	XmlEntities["mdash"] = "—"
	XmlEntities["lsquo"] = "‘"
	XmlEntities["rsquo"] = "’"
	XmlEntities["sbquo"] = "‚"
	XmlEntities["ldquo"] = "“"
	XmlEntities["rdquo"] = "”"
	XmlEntities["bdquo"] = "„"
	XmlEntities["dagger"] = "†"
	XmlEntities["Dagger"] = "‡"
	XmlEntities["bull"] = "•"
	XmlEntities["hellip"] = "…"
	XmlEntities["permil"] = "‰"
	XmlEntities["prime"] = "'"
	XmlEntities["Prime"] = "?"
	XmlEntities["lsaquo"] = "‹"
	XmlEntities["rsaquo"] = "›"
	XmlEntities["oline"] = "?"
	XmlEntities["frasl"] = "/"
	XmlEntities["euro"] = "€"
	XmlEntities["image"] = "I"
	XmlEntities["weierp"] = "P"
	XmlEntities["real"] = "R"
	XmlEntities["trade"] = "™"
	XmlEntities["alefsym"] = "?"
	XmlEntities["larr"] = "?"
	XmlEntities["uarr"] = "?"
	XmlEntities["rarr"] = "?"
	XmlEntities["darr"] = "?"
	XmlEntities["harr"] = "?"
	XmlEntities["crarr"] = "?"
	XmlEntities["lArr"] = "?"
	XmlEntities["uArr"] = "?"
	XmlEntities["rArr"] = "?"
	XmlEntities["dArr"] = "?"
	XmlEntities["hArr"] = "?"
	XmlEntities["forall"] = "?"
	XmlEntities["part"] = "?"
	XmlEntities["exist"] = "?"
	XmlEntities["empty"] = "Ø"
	XmlEntities["nabla"] = "?"
	XmlEntities["isin"] = "?"
	XmlEntities["notin"] = "?"
	XmlEntities["ni"] = "?"
	XmlEntities["prod"] = "?"
	XmlEntities["sum"] = "?"
	XmlEntities["minus"] = "-"
	XmlEntities["lowast"] = "*"
	XmlEntities["radic"] = "v"
	XmlEntities["prop"] = "?"
	XmlEntities["infin"] = "8"
	XmlEntities["ang"] = "?"
	XmlEntities["and"] = "?"
	XmlEntities["or"] = "?"
	XmlEntities["cap"] = "n"
	XmlEntities["cup"] = "?"
	XmlEntities["int"] = "?"
	XmlEntities["there4"] = "?"
	XmlEntities["sim"] = "~"
	XmlEntities["cong"] = "?"
	XmlEntities["asymp"] = "˜"
	XmlEntities["ne"] = "?"
	XmlEntities["equiv"] = "="
	XmlEntities["le"] = "="
	XmlEntities["ge"] = "="
	XmlEntities["sub"] = "?"
	XmlEntities["sup"] = "?"
	XmlEntities["nsub"] = "?"
	XmlEntities["sube"] = "?"
	XmlEntities["supe"] = "?"
	XmlEntities["oplus"] = "?"
	XmlEntities["otimes"] = "?"
	XmlEntities["perp"] = "?"
	XmlEntities["sdot"] = "·"
	XmlEntities["lceil"] = "?"
	XmlEntities["rceil"] = "?"
	XmlEntities["lfloor"] = "?"
	XmlEntities["rfloor"] = "?"
	XmlEntities["lang"] = "<"
	XmlEntities["rang"] = ">"
	XmlEntities["loz"] = "?"
	XmlEntities["spades"] = "?"
	XmlEntities["clubs"] = "?"
	XmlEntities["hearts"] = "?"
	XmlEntities["diams"] = "?"

	IsXmlEntitiesInitialized = true

end sub

function TranslateXmlEntity(e as string) as string

	if not IsXmlEntitiesInitialized then InitializeXmlEntities()

	if e.Match("^#x") then

		'&#x1234; hex charcode entity
		e.Erase(0, 2)
		dim cc as integer = HexToInt(e)
		TranslateXmlEntity = Chr(cc)

	elseif e.Match("^#\\d") then

		'&#12345; decimal charcode entity
		e.Erase(0, 1)
		dim cc as integer = CInt(e)
		TranslateXmlEntity = Chr(cc)

	elseif XmlEntities.ContainsKey(e) then

		TranslateXmlEntity = XmlEntities[e]

	else

		TranslateXmlEntity = "?" ' ERROR

	end if
	
end function

function FindElement(byref node as XmlNode, elementName as string) as XmlNode

	dim all as Array[XmlNode] = FindElements(node, elementName)
	if all.Size = 0 then
		FindElement.Type = "none"
	else
		FindElement = all[0]
	end if

end function

function FindElement(byref node as XmlNode, elementName as string, attributeName as string, attributeValue as string) as XmlNode

	dim all as Array[XmlNode] = FindElements(node, elementName, attributeName, attributeValue)
	if all.Size = 0 then
		FindElement.Type = "none"
	else
		FindElement = all[0]
	end if

end function

function FindElements(byref node as XmlNode, elementName as string) as Array[XmlNode]

	dim all as Array[XmlNode]
	dim i as integer
	for i = node.Children.LBound to node.Children.UBound
		if (node.Children[i].Type = "element" and node.Children[i].Name = elementName) then
			all.Push( node.Children[i] )
		end if
	next
	FindElements = all

end function

function FindElements(byref node as XmlNode, elementName as string, attributeName as string, attributeValue as string) as Array[XmlNode]

	dim all as Array[XmlNode]
	dim i as integer
	for i = node.Children.LBound to node.Children.UBound
		dim c as XmlNode = node.Children[i]
		if (c.Type = "element") and (c.Name = elementName) and (c.Attributes[attributeName] = attributeValue) then
			all.Push( node.Children[i] )
		end if
	next
	FindElements = all

end function

function FlattenElement(byref node as XmlNode) as String

	if (node.Type == "text" or node.Type == "cdata") then
		FlattenElement = node.Value
	else
		dim s as string
		dim i as integer
		for i = node.Children.LBound to node.Children.UBound
			s = s & FlattenElement(node.Children[i])
		next i
		FlattenElement = s
	end if

end function

function HexToInt(byval hexStr as String) as Integer

	dim hexChars as string = "0123456789abcdef"
	dim s as string = hexStr
	s.MakeLower()
	dim value as integer = 0
	dim i as integer
	for i = 0 to s.Length-1
		dim ch as string = s.GetChar(i)
		value = (value * 16) + hexChars.Find(ch)
	next	
	
	HexToInt = value
	
end function