private void HandleFromClause(QueryExpression node, FromClauseExpression fromExpr, int i)
{
var e2 = fromExpr.Container;
BlockExpression l1 = MakeLambda(_range, e2);
if (i == node.Clauses.Count - 1 && node.Ending is SelectClauseExpression)
{
var l2 = MakeLambda(_range, fromExpr.Identifier, node.Ending.BaseExpr);
BlockExpression[] lambdas = { l1, l2 };
var sm = MakeMethodCall("SelectMany", lambdas);
Simplify(fromExpr, sm);
node.Ending = null;
}
else
{
var constructor = MakeTupleConstructor(_range, fromExpr.Identifier, TupleDepth(fromExpr));
var l2 = MakeLambda(_range, fromExpr.Identifier, constructor);
BlockExpression[] lambdas = { l1, l2 };
var sm = MakeMethodCall("SelectMany", lambdas);
Simplify(fromExpr, sm);
string name;
InjectTransparentIdentifier(node, i, TupleDepth(fromExpr), _range, fromExpr.Identifier, out name);
_range = new Declaration(name, null);
FromClause(node).Identifier = _range;
}
}
override public void OnFromClauseExpression(FromClauseExpression node)
{
if (node.DeclaredType)
{
var typ = node.Identifier.Type;
var gen = new GenericReferenceExpression(typ.LexicalInfo);
gen.GenericArguments.Add(typ);
gen.Target = new MemberReferenceExpression(node.Container, "Cast");
var inv = new MethodInvocationExpression(node.Container.LexicalInfo, gen);
node.Container = inv;
}
base.OnFromClauseExpression(node);
}
override public void OnQueryExpression(QueryExpression node)
{
if (node.Cont != null)
{
QueryContinuationExpression cont = node.Cont;
node.Cont = null;
QueryExpression outer = cont.Body.CloneNode();
outer.LexicalInfo = node.LexicalInfo;
var newFrom = new FromClauseExpression(FromClause(node).LexicalInfo);
newFrom.Container = node;
outer.Clauses.Insert(0, newFrom);
ReplaceCurrentNode(outer);
}
base.OnQueryExpression(node);
}
