public override VfpExpression Visit(VfpOrExpression expression)
{
var list = OrComparisonGatherer.Gather(expression);
if (!list.Any())
{
return(base.Visit(expression));
}
var comparison = list.Select(x => new {
x.ExpressionKind,
LeftExpression = x.Left,
LeftDbConstantExpression = ConstantGatherer.Gather(x.Left).FirstOrDefault(),
RightExpression = x.Right,
RightDbPropertyExpression = PropertyGatherer.Gather(x.Right).FirstOrDefault(),
RightDbVariableReferenceExpression = VariableReferenceGatherer.Gather(x.Right).FirstOrDefault()
}).First();
if (comparison.ExpressionKind != VfpExpressionKind.Equals && comparison.ExpressionKind != VfpExpressionKind.NotEquals)
{
return(base.Visit(expression));
}
if (comparison.LeftDbConstantExpression == null || comparison.RightDbPropertyExpression == null || comparison.RightDbVariableReferenceExpression == null)
{
return(base.Visit(expression));
}
var expressions = list.Select(x => new {
x.ExpressionKind,
LeftExpression = x.Left,
LeftDbConstantExpression = ConstantGatherer.Gather(x.Left).FirstOrDefault(),
RightExpression = x.Right,
RightDbPropertyExpression = PropertyGatherer.Gather(x.Right).FirstOrDefault(),
RightDbVariableReferenceExpression = VariableReferenceGatherer.Gather(x.Right).FirstOrDefault()
})
.Where(x => x.LeftDbConstantExpression != null)
.Where(x => x.RightDbPropertyExpression != null)
.Where(x => x.RightDbVariableReferenceExpression != null)
.ToList();
if (list.Count != expressions.Count)
{
return(base.Visit(expression));
}
if (!expressions.All(x => x.LeftDbConstantExpression.ConstantKind == comparison.LeftDbConstantExpression.ConstantKind &&
x.LeftDbConstantExpression.ResultType == comparison.LeftDbConstantExpression.ResultType &&
x.RightDbPropertyExpression.Property == comparison.RightDbPropertyExpression.Property &&
x.RightDbVariableReferenceExpression.VariableName == comparison.RightDbVariableReferenceExpression.VariableName))
{
return(base.Visit(expression));
}
var inExpression = comparison.RightExpression.In(list.Select(x => x.Left).ToList().List());
return(base.Visit(inExpression));
}
public static ReadOnlyCollection <VfpComparisonExpression> Gather(VfpOrExpression expression)
{
var visitor = new OrComparisonGatherer();
visitor.Visit(expression);
if (visitor._invalid)
{
visitor._expressions.Clear();
}
return(visitor._expressions.AsReadOnly());
}
public override VfpExpression Visit(VfpOrExpression expression)
{
return(Visit((VfpBinaryExpression)expression));
}
public override VfpExpression Visit(VfpOrExpression expression)
{
_canRewrite = false;
return(base.Visit(expression));
}
public virtual VfpExpression Visit(VfpOrExpression expression)
{
return(new VfpOrExpression(expression.ResultType,
expression.Left.Accept(this),
expression.Right.Accept(this)));
}