/// <summary>
/// Returns a constructed type given its instance type and type arguments.
/// </summary>
/// <param name="instanceType">the instance type to construct the result from</param>
/// <param name="typeArguments">the immediate type arguments to be replaced for type parameters in the instance type</param>
/// <returns></returns>
internal static NamedTypeSymbol Construct1(this NamedTypeSymbol instanceType, ReadOnlyArray <TypeSymbol> typeArguments)
{
Debug.Assert(instanceType.ConstructedFrom == instanceType);
var sequenceEqual = true;
var args = instanceType.TypeArguments;
if (args.Count != typeArguments.Count)
{
sequenceEqual = false;
}
else
{
for (int i = 0; i < args.Count; i++)
{
if (args[i] != typeArguments[i])
{
sequenceEqual = false;
break;
}
}
}
return(sequenceEqual
? instanceType
: ConstructedNamedTypeSymbol.Make(instanceType, typeArguments));
}
/// <summary>
/// </summary>
/// <param name="namedTypeSymbol">
/// </param>
/// <param name="map">
/// </param>
/// <returns>
/// </returns>
private static ConstructedNamedTypeSymbol ConstructGenericTypeSymbol(NamedTypeSymbol namedTypeSymbol, IDictionary <IType, IType> map)
{
var mapFilteredByTypeParameters = namedTypeSymbol.TypeArguments != null
? SelectGenericsFromArguments(namedTypeSymbol, map)
: SelectGenericsFromParameters(namedTypeSymbol, map);
if (mapFilteredByTypeParameters == null)
{
return(null);
}
var newType = new ConstructedNamedTypeSymbol(namedTypeSymbol.ConstructedFrom, ImmutableArray.Create(mapFilteredByTypeParameters));
return(newType);
}