private SyntaxNode CreateThroughExpression(SyntaxGenerator factory)
{
var through = ThroughMember.IsStatic
? GenerateName(factory, State.ClassOrStructType.IsGenericType)
: factory.ThisExpression();
through = factory.MemberAccessExpression(
through, factory.IdentifierName(ThroughMember.Name));
var throughMemberType = ThroughMember.GetMemberType();
if ((State.InterfaceTypes != null) && (throughMemberType != null))
{
// In the case of 'implement interface through field / property' , we need to know what
// interface we are implementing so that we can insert casts to this interface on every
// usage of the field in the generated code. Without these casts we would end up generating
// code that fails compilation in certain situations.
//
// For example consider the following code.
// class C : IReadOnlyList<int> { int[] field; }
// When applying the 'implement interface through field' code fix in the above example,
// we need to generate the following code to implement the Count property on IReadOnlyList<int>
// class C : IReadOnlyList<int> { int[] field; int Count { get { ((IReadOnlyList<int>)field).Count; } ...}
// as opposed to the following code which will fail to compile (because the array field
// doesn't have a property named .Count) -
// class C : IReadOnlyList<int> { int[] field; int Count { get { field.Count; } ...}
//
// The 'InterfaceTypes' property on the state object always contains only one item
// in the case of C# i.e. it will contain exactly the interface we are trying to implement.
// This is also the case most of the time in the case of VB, except in certain error conditions
// (recursive / circular cases) where the span of the squiggle for the corresponding
// diagnostic (BC30149) changes and 'InterfaceTypes' ends up including all interfaces
// in the Implements clause. For the purposes of inserting the above cast, we ignore the
// uncommon case and optimize for the common one - in other words, we only apply the cast
// in cases where we can unambiguously figure out which interface we are trying to implement.
var interfaceBeingImplemented = State.InterfaceTypes.SingleOrDefault();
if ((interfaceBeingImplemented != null) && (!throughMemberType.Equals(interfaceBeingImplemented)))
{
through = factory.CastExpression(interfaceBeingImplemented,
through.WithAdditionalAnnotations(Simplifier.Annotation));
var facts = this.Document.GetLanguageService<ISyntaxFactsService>();
through = facts.Parenthesize(through);
}
}
return through.WithAdditionalAnnotations(Simplifier.Annotation);
}
private static IList<SyntaxNode> CreateEqualsMethodStatements(
SyntaxGenerator factory,
Compilation compilation,
INamedTypeSymbol containingType,
IEnumerable<ISymbol> members,
CancellationToken cancellationToken)
{
var statements = new List<SyntaxNode>();
var parts = StringBreaker.BreakIntoWordParts(containingType.Name);
string localName = "v";
for (int i = parts.Count - 1; i >= 0; i--)
{
var p = parts[i];
if (char.IsLetter(containingType.Name[p.Start]))
{
localName = containingType.Name.Substring(p.Start, p.Length).ToCamelCase();
break;
}
}
var localNameExpression = factory.IdentifierName(localName);
var objNameExpression = factory.IdentifierName(ObjName);
var expressions = new List<SyntaxNode>();
if (containingType.IsValueType)
{
#if false
if (!(obj is MyType))
{
return false;
}
#endif
var ifStatement = factory.IfStatement(
factory.LogicalNotExpression(
factory.IsTypeExpression(
objNameExpression,
containingType)),
new[] { factory.ReturnStatement(factory.FalseLiteralExpression()) });
#if false
var myType = (MyType)obj;
#endif
var localDeclaration = factory.LocalDeclarationStatement(localName, factory.CastExpression(containingType, objNameExpression));
statements.Add(ifStatement);
statements.Add(localDeclaration);
}
else
{
#if false
var myType = obj as MyType;
#endif
var localDeclaration = factory.LocalDeclarationStatement(localName, factory.TryCastExpression(objNameExpression, containingType));
statements.Add(localDeclaration);
#if false
myType != null
#endif
expressions.Add(factory.ReferenceNotEqualsExpression(localNameExpression, factory.NullLiteralExpression()));
if (HasExistingBaseEqualsMethod(containingType, cancellationToken))
{
#if false
base.Equals(obj)
#endif
expressions.Add(factory.InvocationExpression(
factory.MemberAccessExpression(
factory.BaseExpression(),
factory.IdentifierName(EqualsName)),
objNameExpression));
}
}
foreach (var member in members)
{
var symbolNameExpression = factory.IdentifierName(member.Name);
var thisSymbol = factory.MemberAccessExpression(factory.ThisExpression(), symbolNameExpression).WithAdditionalAnnotations(Simplification.Simplifier.Annotation);
var otherSymbol = factory.MemberAccessExpression(localNameExpression, symbolNameExpression);
#if false
EqualityComparer<SType>.Default.Equals(this.S1, myType.S1)
#endif
var expression =
factory.InvocationExpression(
factory.MemberAccessExpression(
GetDefaultEqualityComparer(factory, compilation, member),
factory.IdentifierName(EqualsName)),
thisSymbol,
otherSymbol);
expressions.Add(expression);
}
#if false
return myType != null && base.Equals(obj) && EqualityComparer<int>.Default.Equals(this.S1, myType.S1) && ...;
#endif
statements.Add(factory.ReturnStatement(
expressions.Aggregate(factory.LogicalAndExpression)));
return statements;
}
