override sealed public void Visit(PlaceHolderPredicate predicate)
{
//
// プレースホルダに当てはまるPredicate式にvisitorを適用する
//
if (!_placeHolders.ContainsKey(predicate.LabelName))
{
this.VisitOnPlaceHolder(predicate);
return;
}
if (!(_placeHolders[predicate.LabelName] is Predicate))
{
throw new CannotBuildASTException("Type of placeholder value is mismatched.");
}
var placeValue = (Predicate)(_placeHolders[predicate.LabelName]);
if (this.NeedsBracket(predicate.Parent, placeValue))
{
// 定義されたPredicate演算子の優先順位に基づき、
// 必要であればプレースホルダ値を括弧で囲む
(new BracketedPredicate(placeValue)).Accept(this);
}
else
{
placeValue.Accept(this);
}
}
protected override Predicate Place(PlaceHolderPredicate ph)
{
// 0=1は全てのPlaceHolderPredicateに適用できる
// FALSE値に置き換えることでSELECT文の高速化を期待できる
return(new BinaryOpPredicate(new UNumericLiteral("0")
, PredicateOperator.Equal
, new UNumericLiteral("1")));
}
private Predicate PlaceInCollate(PlaceHolderPredicate ph)
{
var predicate = this.Place(ph);
if (predicate.GetType() == typeof(AndPredicate) ||
predicate.GetType() == typeof(OrPredicate))
{
predicate = new BracketedPredicate(predicate);
}
return(predicate);
}
private Predicate PlaceInAnd(PlaceHolderPredicate ph)
{
var predicate = this.Place(ph);
if (predicate.GetType() == typeof(OrPredicate))
{
// OR演算式の場合は式全体を括弧で囲んでAND節をつなげる
predicate = new BracketedPredicate(predicate);
}
return(predicate);
}
public void Visit(PlaceHolderPredicate predicate)
{
// プレースホルダに当てはまるPredicate式に_visitorを適用する
if (_placeHolders.ContainsKey(predicate.LabelName))
{
_placeHolders[predicate.LabelName].Accept(_visitor);
}
else
{
_visitor.Visit(predicate);
}
}
protected virtual Predicate Place(PlaceHolderPredicate ph)
{
var placeHolderName = ph.LabelName;
if (!_placeHolders.ContainsKey(placeHolderName))
{
return(ph);
}
var placeHolderValue = _placeHolders[placeHolderName];
if (placeHolderValue is Expr)
{
throw new CannotBuildASTException("Type of placeholder value is mismatched.");
}
// 適用したプレースホルダを記録する
if (!_placedHolders.ContainsKey(placeHolderName))
{
_placedHolders.Add(placeHolderName, placeHolderValue);
}
return((Predicate)placeHolderValue);
}
virtual public void Visit(PlaceHolderPredicate predicate)
{
}
public override void Visit(PlaceHolderPredicate predicate)
{
var node = new PlaceHolderPredicate(predicate.Label, predicate.Comments.Clone());
_stack.Push(node);
}
virtual protected void VisitOnPlaceHolder(PlaceHolderPredicate predicate)
{
}
public override void Visit(PlaceHolderPredicate predicate)
{
this.GetPlaceHolderInfo(predicate.LabelName);
}
