private IMethodSymbol FindConstructorToDelegateTo(
ImmutableArray <IParameterSymbol> parameters,
ImmutableArray <TExpressionSyntax> expressions,
ImmutableArray <IMethodSymbol> constructors,
CancellationToken cancellationToken)
{
foreach (var constructor in constructors)
{
// Don't bother delegating to an implicit constructor. We don't want to add `: base()` as that's just
// redundant for subclasses and `: this()` won't even work as we won't have an implicit constructor once
// we add this new constructor.
if (constructor.IsImplicitlyDeclared)
{
continue;
}
// Don't delegate to another constructor in this type if it's got the same parameter types as the
// one we're generating. This can happen if we're generating the new constructor because parameter
// names don't match (when a user explicitly provides named parameters).
if (TypeToGenerateIn.Equals(constructor.ContainingType) &&
constructor.Parameters.Select(p => p.Type).SequenceEqual(ParameterTypes))
{
continue;
}
if (GenerateConstructorHelpers.CanDelegateTo(_document, parameters, expressions, constructor) &&
!_service.WillCauseConstructorCycle(this, _document, constructor, cancellationToken))
{
return(constructor);
}
}
return(null);
}
private bool IsCompatible(IMethodSymbol constructor, List <ITypeSymbol> parameterTypes)
{
Debug.Assert(constructor.Parameters.Length == parameterTypes.Count);
// Don't delegate to another constructor in this type. if we're generating a new constructor with the
// same parameter types. Note: this can happen if we're generating the new constructor because
// parameter names don't match (when a user explicitly provides named parameters).
if (TypeToGenerateIn.Equals(constructor.ContainingType) && constructor.Parameters.Select(p => p.Type).SequenceEqual(this.ParameterTypes))
{
return(false);
}
var compilation = _document.SemanticModel.Compilation;
for (var i = 0; i < constructor.Parameters.Length; i++)
{
var constructorParameter = constructor.Parameters[i];
var conversion = compilation.ClassifyCommonConversion(parameterTypes[i], constructorParameter.Type);
if (!conversion.IsIdentity && !conversion.IsImplicit)
{
return(false);
}
}
return(true);
}
