private object EvaluateValue(Expression expression)
{
var value = _item.Data;
while(expression != null && value != null)
{
if(expression.Dollar)
value = _item;
var memberInfo = FindMember(expression.Member, value);
if(memberInfo.Length == 0 && _item.Options != null)
memberInfo = FindMember(expression.Member, value = _item.Options);
if(memberInfo.Length > 0)
value = InvokeBestMatch(memberInfo, expression, value);
else if(_item.ValueParameter != null && _item.ValueParameter.Matches(expression.Member))
value = _item.Value;
else if(_item.IndexParameter != null && _item.IndexParameter.Matches(expression.Member))
value = _item.Index;
else
value = EvaluateLiteral(expression);
if(expression.Operator.Length > 0)
return new BinaryEvaluator().Evaluate(value, EvaluateValue(expression.Next), expression.Operator);
expression = expression.Next;
}
return value;
}
private object EvaluateLiteral(Expression expression)
{
if(expression.Arguments.Length == 0 && expression.Indices.Length == 0 && expression.Dollar == false)
{
int number;
if(Int32.TryParse(expression.Member, out number))
return number;
bool boolean;
if(Boolean.TryParse(expression.Member, out boolean))
return boolean;
if((expression.Member.StartsWith("\"") && expression.Member.EndsWith("\"")) ||
(expression.Member.StartsWith("'") && expression.Member.EndsWith("'")))
return expression.Member.Trim('"', '\'');
}
return null;
}
private object InvokeBestMatch(MemberInfo[] candidates, Expression expression, object target)
{
if(expression.Member == null)
return null;
foreach(var memberInfo in candidates)
{
var propertyInfo = memberInfo as PropertyInfo;
if(propertyInfo != null)
{
var value = propertyInfo.GetValue(target, null);
if(expression.Arguments.Length > 0 && value is Delegate)
{
var func = (Delegate)value;
var paramValues = expression.Arguments.Select(EvaluateValue).ToArray();
return func.DynamicInvoke(paramValues);
}
if(expression.Indices.Length > 0)
{
if(value is Array)
{
var subIndices = expression.Indices.Select(EvaluateValue).Cast<int>().ToArray();
value = ((Array)value).GetValue(subIndices);
}
else if(value != null)
{
var indexer = value.GetType().GetProperty("Item") ?? value.GetType().GetProperty("Chars");
if(indexer != null)
{
var subIndices = expression.Indices.Select(EvaluateValue).ToArray();
value = indexer.GetValue(value, subIndices);
}
}
}
return value;
}
var fieldInfo = memberInfo as FieldInfo;
if(fieldInfo != null)
{
if(expression.Arguments.Length > 0)
continue;
if(expression.Indices.Length > 0)
continue;
return fieldInfo.GetValue(target);
}
var methodInfo = memberInfo as MethodInfo;
if(methodInfo != null)
{
var methodParameters = methodInfo.GetParameters();
if(methodParameters.Length == expression.Arguments.Length)
{
var paramValues = expression.Arguments.Select(EvaluateValue).ToArray();
var value = methodInfo.Invoke(target, paramValues);
if(expression.Indices.Length > 0)
{
if(value is Array)
{
var indices = expression.Indices.Select(EvaluateValue).Cast<int>().ToArray();
value = ((Array)value).GetValue(indices);
}
else if(value != null)
{
var indexer = value.GetType().GetProperty("Item");
if(indexer != null)
{
var indices = expression.Indices.Select(EvaluateValue).ToArray();
value = indexer.GetValue(value, indices);
}
}
}
return value;
}
}
}
return null;
}
public EvaluatedExpression Evaluate(Expression expression)
{
var value = EvaluateValue(expression);
return new EvaluatedExpression(_item, value);
}