public static List <Expression> Search <TExpression>(Expression expression) where TExpression : Expression
{
var searcher = new ExpressionSearcher(e => e is TExpression);
searcher.Visit(expression);
return(searcher.nodes.ToList());
}
public static List <Expression> Search(Expression expression, Func <Expression, bool> criteria, Func <Expression, bool> parentExclusionCriteria = null)
{
var searcher = new ExpressionSearcher(criteria, parentExclusionCriteria);
searcher.Visit(expression);
return(searcher.nodes.ToList());
}
private bool GetDirection(BinaryExpression binary)
{
if (ExpressionSearcher.Search <PropertyExpression>(binary.Left).Count > 0)
{
return(true);
}
return(false);
}
private bool DifferentEnumTypesInternal(Expression node, Expression first, Expression second, out Expression outExpr)
{
var firstUnwrapped = SubstituteExpression.Strip(ExpressionHelpers.UnwrapCast(first));
var secondUnwrapped = SubstituteExpression.Strip(ExpressionHelpers.UnwrapCast(second));
if (IsEnum(firstUnwrapped) && IsEnum(secondUnwrapped))
{
var property = ExpressionSearcher.Search(firstUnwrapped, p => p is PropertyExpression).FirstOrDefault();
if (property != null)
{
var comparison = ExpressionSearcher.Search(secondUnwrapped, e => IsEnum(e) && e.NodeType != ExpressionType.Convert && e.NodeType != ExpressionType.ConvertChecked);
var firstComparison = comparison.FirstOrDefault();
if (firstComparison != null)
{
if (firstComparison.Type.IsEnum && firstComparison.Type != property.Type)
{
if (strict)
{
throw Error.InvalidEnumComparison(node, firstUnwrapped, secondUnwrapped);
}
Logger.Log($"Condition {node} compares enums of different types. Reducing to 'True'", Indentation.Six);
outExpr = Expression.Constant(true);
return(true);
}
else
{
var constant = firstComparison as ConstantExpression;
if (constant != null)
{
if (property.Type != constant.Value.GetType())
{
Logger.Log($"Condition {node} compares enums of different types. Reducing to 'True'", Indentation.Six);
if (strict)
{
throw Error.InvalidEnumComparison(node, firstUnwrapped, secondUnwrapped);
}
outExpr = Expression.Constant(true);
return(true);
}
}
}
}
}
}
outExpr = null;
return(false);
}
private bool IsLiteralMemberInitExpression(MemberInitExpression init, Expression source)
{
//That is to say, we are not the MemberInitExpression defined in method CreateSourceExpression()
if (init.Type != typeof(T))
{
return(true);
}
//We ARE a MemberInitExpression of type T, but are we a REAL PropertyExpression with a backing MemberExpression,
//or a fake one used to perform property lookups.
if (ExpressionSearcher.Search(source, e => e is PropertyExpression).Cast <PropertyExpression>()
.Any(p => p.Expression != null))
{
//We're a MemberInitExpression for type T. If we did new Sensor { Message = <root>.Name }.Message,
//continuing with normal MemberInitExpression parsing logic would reduce us to <root>.Message,
//eliminating the reference to <root>.Name. As such, we will need to perform a lookup on the
//assignment "source", which will allow us to determine the whole thing can in fact be replaced
//with <root>.Name
return(true);
}
return(false);
}
private Expression PropertyExpressionFromArray(MemberExpression node, Expression source)
{
var exprs = ExpressionSearcher.Search <NewExpression>(source);
Expression expr;
if (exprs.Cast <NewExpression>().All(e => e.Members == null))
{
var memberInit = ExpressionSearcher.Search <MemberInitExpression>(source);
if (memberInit.Count > 0)
{
exprs = memberInit;
}
foreach (var e in exprs)
{
if (PropertyExpressionFromInit(node, e, out expr))
{
return(expr);
}
}
}
else
{
foreach (var e in exprs)
{
if (PropertyExpressionFromPrevious(node, e, out expr))
{
return(expr);
}
}
}
throw new InvalidOperationException($"Failed to find member '{node}' in source expression array. This should be impossible");
}
private bool IsLegalCondition(Expression node)
{
//We DON'T use IsBinaryCondition here, since we want to know whether we might have something illegal
//like ((s.Id + 1) == 3)
return(ExpressionSearcher.Search(node, e => (e is BinaryExpression & e.NodeType != ExpressionType.ArrayIndex) || IsMethodCondition(e)).Count > 0);
}
