/// <summary>
/// Optimizes the filter contains expressions.
/// </summary>
/// <param name="expr">The expr.</param>
/// <returns></returns>
private static Expression OptimizeFilterContainsExpressions(Expression expr)
{
var nullEqualConditionalMatch = ExpressionUtil.MatchNullEqualConditional(expr);
if (nullEqualConditionalMatch != null &&
nullEqualConditionalMatch.ComparisonOperand.Type == typeof(String))
{
if (((MemberExpression)nullEqualConditionalMatch.ComparisonOperand).Member.Name == ((MemberExpression)((MethodCallExpression)((UnaryExpression)nullEqualConditionalMatch.IfNotNull).Operand).Object).Member.Name)
{
return(ExpressionUtil.RemoveConversionsAndTypeAs(nullEqualConditionalMatch.IfNotNull));
}
}
return(expr);
}
/// <summary>
/// ConditionalExpression visit method
/// </summary>
/// <param name="c">The ConditionalExpression expression to visit</param>
/// <returns>
/// The visited ConditionalExpression expression
/// </returns>
internal override Expression VisitConditional(ConditionalExpression c)
{
var nullEqualConditionalMatch = ExpressionUtil.MatchNullEqualConditional(c);
if (nullEqualConditionalMatch != null &&
nullEqualConditionalMatch.ComparisonOperand.Type == typeof(String))
{
if (((MemberExpression)nullEqualConditionalMatch.ComparisonOperand).Member.Name == ((MemberExpression)((MethodCallExpression)((UnaryExpression)nullEqualConditionalMatch.IfNotNull).Operand).Object).Member.Name)
{
return(ExpressionUtil.RemoveConversionsAndTypeAs(nullEqualConditionalMatch.IfNotNull));
}
}
return(base.VisitConditional(c));
}
/// <summary>
/// Optimizes the filter nullable boolean to condition.
/// </summary>
/// <param name="expr">The expr.</param>
/// <returns></returns>
private static Expression OptimizeFilterNullableBooleanToCondition(Expression expr)
{
if (expr.Type == typeof(bool))
{
var nullEqualConditionalMatch = ExpressionUtil.MatchNullEqualConditional(expr);
if (nullEqualConditionalMatch != null &&
nullEqualConditionalMatch.ComparisonOperand.Type == typeof(bool?) &&
ExpressionUtil.IsFalseConstant(nullEqualConditionalMatch.IfNull) &&
ExpressionUtil.IsMemberAccess(nullEqualConditionalMatch.IfNotNull, "Value"))
{
// (c == null) ? false : c.Value (bool?)c
// =>
// c == (bool?)true
return(Expression.Equal(
nullEqualConditionalMatch.ComparisonOperand,
Expression.Constant(true, typeof(bool?))));
}
}
return(expr);
}