protected override TypeVariableReference ComputeTypeToUnifyWith(VariableReference inputFacadeVariable, out bool setExpectedMutable)
{
setExpectedMutable = false;
TypeVariableReference other = inputFacadeVariable.TypeVariableReference;
TypeVariableReference u, l;
bool otherIsMutableReference;
bool otherIsReference = TypeVariableSet.TryDecomposeReferenceType(other, out u, out l, out otherIsMutableReference);
TypeVariableReference underlyingType = otherIsReference ? u : other;
string typeName = TypeVariableSet.GetTypeName(underlyingType);
bool underlyingTypeIsStringSlice = typeName == DataTypes.StringSliceType.GetName(),
underlyingTypeIsString = typeName == NITypes.String.GetName();
bool inputCoercesToStringSlice = underlyingTypeIsString || underlyingTypeIsStringSlice;
bool needsBorrow = !otherIsReference || !underlyingTypeIsStringSlice;
TypeVariableReference lifetimeType = otherIsReference
? l
: TypeVariableSet.CreateReferenceToLifetimeType(_group.BorrowLifetime);
if (needsBorrow)
{
_stringToSliceNeeded = true;
_group.SetBorrowRequired(false);
}
// If the input is allowed to coerce to a str, we can unify with str;
// otherwise, unify with the underlying type to get a type mismatch.
TypeVariableReference toUnifyUnderlyingType = inputCoercesToStringSlice
? TypeVariableSet.CreateTypeVariableReferenceFromNIType(DataTypes.StringSliceType)
: underlyingType;
return(TypeVariableSet.CreateReferenceToReferenceType(
false,
toUnifyUnderlyingType,
lifetimeType));
}
public void AddTerminalFacade(Terminal inputTerminal, TypeVariableReference referentTypeReference, TypeVariableReference mutabilityTypeReference, Terminal terminateLifetimeOutputTerminal = null)
{
TypeVariableReference referenceType;
TypeVariableSet typeVariableSet = inputTerminal.GetTypeVariableSet();
if (_mutability == InputReferenceMutability.Polymorphic)
{
referenceType = typeVariableSet.CreateReferenceToPolymorphicReferenceType(
mutabilityTypeReference,
referentTypeReference,
LifetimeType);
}
else
{
referenceType = typeVariableSet.CreateReferenceToReferenceType(
(_mutability != InputReferenceMutability.AllowImmutable),
referentTypeReference,
LifetimeType);
}
if (_lazyBorrowLifetime.IsValueCreated)
{
throw new InvalidOperationException("Cannot add borrowed variables after creating new lifetime.");
}
bool isStringSliceReference = typeVariableSet.GetTypeName(referentTypeReference) == DataTypes.StringSliceType.GetName();
TerminalFacade terminalFacade;
if (isStringSliceReference)
{
terminalFacade = new StringSliceReferenceInputTerminalFacade(inputTerminal, this, referenceType);
}
else
{
terminalFacade = new ReferenceInputTerminalFacade(inputTerminal, _mutability, this, referenceType);
}
_nodeFacade[inputTerminal] = terminalFacade;
_facades.Add(terminalFacade);
if (terminateLifetimeOutputTerminal != null)
{
var outputFacade = new TerminateLifetimeOutputTerminalFacade(terminateLifetimeOutputTerminal, terminalFacade);
_nodeFacade[terminateLifetimeOutputTerminal] = outputFacade;
}
}
public override void UnifyWithConnectedWireTypeAsNodeInput(VariableReference wireFacadeVariable, ITypeUnificationResultFactory unificationResultFactory)
{
TypeVariableSet typeVariableSet = Terminal.GetTypeVariableSet();
Terminal.UnifyTerminalTypeWith(TrueVariable.TypeVariableReference, wireFacadeVariable.TypeVariableReference, unificationResultFactory);
TrueVariable.MergeInto(wireFacadeVariable);
TypeVariableReference optionType;
if (typeVariableSet.GetTypeName(TrueVariable.TypeVariableReference) == "Option")
{
optionType = TrueVariable.TypeVariableReference;
}
else
{
optionType = typeVariableSet.CreateReferenceToOptionType(TrueVariable.TypeVariableReference);
}
TypeVariableReference outputTypeReference = _outputTerminalFacade.TrueVariable.TypeVariableReference;
_outputTerminalFacade.Terminal.UnifyTerminalTypeWith(outputTypeReference, optionType, unificationResultFactory);
}