public override ClassDeclarationSyntax ProcessApplyToClassDeclaration(ClassDeclarationSyntax applyTo)
{
applyTo = base.ProcessApplyToClassDeclaration(applyTo);
if (this.applyTo.IsRecursiveParentOrDerivative)
{
// Add the lookupTable parameter to the constructor's signature.
var origCtor = applyTo.Members.OfType<ConstructorDeclarationSyntax>().Single();
var alteredCtor = origCtor.AddParameterListParameters(SyntaxFactory.Parameter(LookupTableFieldName.Identifier).WithType(Syntax.OptionalOf(this.lookupTableType)));
// If this type isn't itself the recursive parent then we derive from it. And we must propagate the value to the chained base type.
if (!this.applyTo.IsRecursiveParent)
{
Assumes.NotNull(alteredCtor.Initializer); // we expect a chained call to the base constructor.
alteredCtor = alteredCtor.WithInitializer(
alteredCtor.Initializer.AddArgumentListArguments(
SyntaxFactory.Argument(SyntaxFactory.NameColon(LookupTableFieldName), NoneToken, LookupTableFieldName)));
}
// Apply the updated constructor back to the generated type.
applyTo = applyTo.ReplaceNode(origCtor, alteredCtor);
// Search for invocations of the constructor that we now have to update.
var invocations = (
from n in applyTo.DescendantNodes()
let ctorInvocation = n as ObjectCreationExpressionSyntax
let instantiatedTypeName = ctorInvocation?.Type?.ToString()
where instantiatedTypeName == this.applyTo.TypeSyntax.ToString() || instantiatedTypeName == this.applyTo.TypeSymbol.Name
select ctorInvocation).ToImmutableArray();
var trackedTree = applyTo.TrackNodes(invocations);
var recursiveField = this.applyTo.RecursiveParent.RecursiveField;
foreach (var ctorInvocation in invocations)
{
var currentInvocation = trackedTree.GetCurrentNode(ctorInvocation);
ExpressionSyntax lookupTableValue = SyntaxFactory.LiteralExpression(SyntaxKind.NullLiteralExpression);
var containingMethod = currentInvocation.FirstAncestorOrSelf<MethodDeclarationSyntax>();
if (containingMethod != null)
{
if (containingMethod.ParameterList.Parameters.Any(p => p.Identifier.ToString() == recursiveField.Name))
{
// We're in a method that accepts the recursive field as a parameter.
// The value we want to pass in for the lookup table is:
// (children.IsDefined && children.Value != this.Children) ? default(Optional<ImmutableDictionary<uint, KeyValuePair<RecursiveType, uint>>>) : Optional.For(this.lookupTable);
lookupTableValue = SyntaxFactory.ConditionalExpression(
SyntaxFactory.ParenthesizedExpression(
SyntaxFactory.BinaryExpression(
SyntaxKind.LogicalAndExpression,
Syntax.OptionalIsDefined(recursiveField.NameAsField),
SyntaxFactory.BinaryExpression(
SyntaxKind.NotEqualsExpression,
Syntax.OptionalValue(recursiveField.NameAsField),
Syntax.ThisDot(recursiveField.NameAsProperty)))),
SyntaxFactory.DefaultExpression(Syntax.OptionalOf(this.lookupTableType)),
Syntax.OptionalFor(Syntax.ThisDot(LookupTableFieldName)));
}
}
var alteredInvocation = currentInvocation.AddArgumentListArguments(
SyntaxFactory.Argument(SyntaxFactory.NameColon(LookupTableFieldName), NoneToken, lookupTableValue));
trackedTree = trackedTree.ReplaceNode(currentInvocation, alteredInvocation);
}
applyTo = trackedTree;
}
return applyTo;
}