/// <summary>
/// Output a given expression tree to a string.
/// </summary>
internal static string ExpressionToString(Expression node)
{
Debug.Assert(node != null);
MindboxExpressionStringBuilder esb = new MindboxExpressionStringBuilder();
esb.Visit(node);
return(esb.ToString());
}
public object Evaluate(Expression expression)
{
var cacheKey = MindboxExpressionStringBuilder.ExpressionToString(expression);
var cachedDelegate = compiledExpressionsCache.GetOrAdd(cacheKey, key =>
{
var arrayOfValuesParameter = Expression.Parameter(typeof(object[]));
var parametrizedBody = Parametrize(expression, arrayOfValuesParameter);
if (parametrizedBody.Type.IsValueType)
{
parametrizedBody = Expression.Convert(parametrizedBody, typeof(object));
}
var effectiveQuery = Expression.Lambda <Func <object[], object> >(
parametrizedBody,
arrayOfValuesParameter
);
return(effectiveQuery.Compile());
});
var capturedValues = GetCapturedValues(expression);
return(cachedDelegate(capturedValues));
}