public ColQueryable <T> Match(params Expression <Func <T, bool> >[] MatchExpr)
{
object ret = Gobbler.GetFilter(MatchExpr);
var match = new BsonDocument("$match", BsonValue.Create(ret));
var retQr = this.Clone <T>();
retQr.Stages.Add(match);
return(retQr);
}
public ColQueryable <T2> Project <T2>(Expression <Func <T, T2> > Selectors)
{
BsonDocument ret = Gobbler.GetFields(Selectors.Body, false);
var match = new BsonDocument("$project", BsonValue.Create(ret));
var retQr = this.Clone <T2>();
retQr.Stages.Add(match);
return(retQr);
}
private static object Gobble(Expression Expr, bool IsExpr)
{
if (Expr is MemberExpression)
{
var md = Expr as MemberExpression;
return(((IsExpr)?"$":"") + md.Member.Name);
}
if (Expr is BinaryExpression)
{
var bx = Expr as BinaryExpression;
var ret = new Hashtable();
ret[Gobbler.GetOp(bx.NodeType)] = new object[]
{
Gobble(bx.Left, true),
Gobble(bx.Right, true)
};
return(ret);
}
if (Expr is ConstantExpression)
{
var val = Expression.Lambda(Expr).Compile().DynamicInvoke();
return(val);
}
if (Expr is MethodCallExpression)
{
var cx = Expr as MethodCallExpression;
if (cx.Method.ReflectedType == typeof(Funcs))
{
if (Gobbler.MultiParamsFuncs.IndexOf(";" + cx.Method.Name.ToLower() + ";") > -1)
{
var ret = new Hashtable();
ret["$" + cx.Method.Name.ToLower()] = Gobbler.Gobble(cx.Arguments, true);
return(ret);
}
else
{
throw new NotImplementedException();
}
}
else
{
throw new NotImplementedException();
}
}
throw new NotImplementedException();
}
internal static BsonDocument GetFields(Expression Expr, bool IsExpr)
{
BsonDocument ret = new BsonDocument();
if (Expr is NewExpression)
{
var nx = Expr as NewExpression;
var memberIndex = 0;
foreach (var x in nx.Arguments)
{
var retField = Gobbler.Gobble(x, IsExpr);
if (retField is string)
{
ret.Add(new BsonElement((string)retField, 1));
}
else if (retField is Hashtable)
{
if (x is BinaryExpression)
{
ret.Add(new BsonElement(nx.Members[memberIndex].Name, BsonValue.Create(retField)));
}
else if (x is MethodCallExpression)
{
var retCompile = Gobble(x, true);
ret.Add(new BsonElement(nx.Members[memberIndex].Name, BsonValue.Create(retCompile)));
}
else
{
throw new NotImplementedException();
}
}
else
{
throw new NotImplementedException();
}
memberIndex++;
}
}
else
{
throw new NotImplementedException();
}
return(ret);
}
