public override Expression Scalar(Expression valueType, BondDataType expectedType, ValueHandler handler)
{
var stringValue = Expression.Variable(typeof(string), "valueAsString");
// Reading primitive field of a struct, or a primitive list item - value is in Xml element text.
// If we have an empty element, parse it as if it has an empty text.
// Otherwise: read once to get to the text, handle the text, read once more to get to the end element.
return(Expression.Block(
new[] { stringValue },
Expression.IfThenElse(
Reader.IsEmptyElement,
Expression.Assign(stringValue, StringExpression.Empty()),
Expression.Block(
Reader.Read(),
Expression.IfThenElse(
Expression.Equal(Reader.NodeType, Expression.Constant(XmlNodeType.EndElement)),
Expression.Assign(stringValue, Expression.Constant(string.Empty)),
Expression.Block(
IfNotNodeType(XmlNodeType.Text, IfNotNodeType(XmlNodeType.Whitespace, ParsingError())),
Expression.Assign(stringValue, Reader.Value),
Reader.Read(),
IfNotNodeType(XmlNodeType.EndElement, ParsingError()))))),
handler(StringExpression.Convert(stringValue, expectedType))));
}
