protected override IElement VisitIfThen(IfThenElement ifThen)
{
ifThen = (IfThenElement)base.VisitIfThen(ifThen);
var cachingField = (FieldInfo)null;
return Matcher
.For(ifThen.Condition)
.OneOf(ExpressionType.Equal)
.AsBinary()
.LeftAndRight(
leftOrRight => leftOrRight.AsPropertyOrField().Field()
.Match(IsLambdaCachingField)
.AssignTo(out cachingField),
leftOrRight => leftOrRight.AsConstant().ValueIsNull()
)
.For(ifThen.Then)
.Count(1)
.For(list => list.Single()).As<MemberAssignmentElement>()
.Match(a => a.Member == cachingField)
.Do(a => collectedFieldValues.Add((FieldInfo)a.Member, a.Value))
.For(ifThen.Else).Count(0)
.IfMatched(() => null, ifThen);
}
private bool TryExtractElseIfThenEndsWithReturn(IfThenElement ifThen, IList<IElement> elements, int index)
{
if (ifThen.Else.Count == 0 || !(ifThen.Then.Last() is ReturnElement))
return false;
elements.InsertRange(index + 1, ifThen.Else);
ifThen.Else.Clear();
return true;
}
protected override IElement VisitIfThen(IfThenElement ifThen)
{
ifThen = (IfThenElement)base.VisitIfThen(ifThen);
if (ifThen.Then.Count != 1 || ifThen.Else.Count != 1)
return ifThen;
var thenAssignment = ifThen.Then[0] as VariableAssignmentElement;
var elseAssignment = ifThen.Else[0] as VariableAssignmentElement;
if (thenAssignment == null || elseAssignment == null || thenAssignment.VariableIndex != elseAssignment.VariableIndex)
return ifThen;
return new VariableAssignmentElement(thenAssignment.VariableIndex, Expression.Condition(
ifThen.Condition, thenAssignment.Value, elseAssignment.Value
));
}
protected override IElement VisitIfThen(IfThenElement ifThen)
{
ifThen = (IfThenElement)base.VisitIfThen(ifThen);
if (ifThen.Else.Count > 0)
return ifThen;
if (ifThen.Then.Count > 1)
return ifThen;
var thenAsIf = ifThen.Then[0] as IfThenElement;
if (thenAsIf == null)
return ifThen;
return new IfThenElement(
Expression.AndAlso(ifThen.Condition, thenAsIf.Condition),
thenAsIf.Then, thenAsIf.Else
);
}
private static void TryInlineIfThenReturnFollowedByReturn(IfThenElement ifThen, IList<IElement> elements, int index)
{
if (index == elements.Count - 1)
return;
if (ifThen.Then.Count != 1 || ifThen.Else.Count > 0)
return;
var returnInIf = ifThen.Then.Single() as ReturnElement;
var returnAfterIf = elements[index + 1] as ReturnElement;
if (returnInIf == null || returnAfterIf == null)
return;
if (returnInIf.Result == null || returnAfterIf.Result == null)
return;
elements[index] = new ReturnElement(Expression.Condition(
ifThen.Condition,
returnInIf.Result,
returnAfterIf.Result
));
elements.RemoveAt(index + 1);
}