static public Dictionary <string, Double> GetNameValueTable(IXamlNameResolver nameResolver,
string expression, out List <string> unknownNames)
{
unknownNames = new List <string>();
var allNames = new List <string>();
var nameValueTable = new Dictionary <string, Double>();
var scanner = new MathExpressionScanner(expression);
foreach (MathExpressionToken scannerTok in scanner.Scan())
{
switch (scannerTok.TokenType)
{
case MathTokenType.Name:
if (!allNames.Contains(scannerTok.Name))
{
allNames.Add(scannerTok.Name);
}
break;
}
}
foreach (string name in allNames)
{
bool isFullyInit;
object obj = nameResolver.Resolve(name, out isFullyInit);
if (obj == null)
{
if (nameResolver.IsFixupTokenAvailable)
{
unknownNames.Add(name);
}
else
{
throw new InvalidOperationException("Could not resolve name {0}");
}
}
else if (!isFullyInit)
{
throw new InvalidOperationException(String.Format("Name {0} is not fully initialized", name));
}
else
{
var num = obj as Number;
if (num == null)
{
throw new InvalidOperationException(String.Format("The Name {0} is of type {1} does not resolve to a Number", name, obj.GetType()));
}
nameValueTable.Add(name, num.Value);
}
}
if (unknownNames.Count == 0)
{
unknownNames = null;
}
return(nameValueTable);
}
// Comp ::= Exp
// Comp ::= Exp == Exp
// Exp ::= Term
// Exp ::= Term (+/-) Exp
// Term ::= Fac
// Term ::= Fac (*|/) Term
// Fac ::= Number
// Fac ::= ( Comp )
public Double Parse(string expression)
{
_scanner = new MathExpressionScanner(expression);
_tokens = _scanner.Scan().GetEnumerator();
_tokens.MoveNext();
CurrentToken = _tokens.Current;
Double value = P_Comparison();
return(value);
}
public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
{
string text = (string)value;
if (text == null)
{
throw new ArgumentException("Missing String Value", "value");
}
var nameResolver = (IXamlNameResolver)context;
if (nameResolver == null)
{
throw new ArgumentException("Missing IXamlNameResolver", "context");
}
var names = new List <string>();
var scanner = new MathExpressionScanner(text);
foreach (MathExpressionToken scannerTok in scanner.Scan())
{
switch (scannerTok.TokenType)
{
case MathTokenType.Name:
if (!names.Contains(scannerTok.Name))
{
names.Add(scannerTok.Name);
}
break;
}
}
var unknownNameList = new List <string>();
var nameValueTable = ExpressionServices.GetNameValueTable(nameResolver, text, out unknownNameList);
if (unknownNameList != null && unknownNameList.Count > 0)
{
object fixup = nameResolver.GetFixupToken(unknownNameList);
return(fixup);
}
// if we have the values of all the names,
// hand it to the expresssion parser and let 'er rip!
//
MathExpressionParser parser = new MathExpressionParser(nameValueTable);
Double number = parser.Parse(text);
return(number);
}