// checkAndComputeOperator handles specialized logic for operator members.
func (mb *MemberDecorator) checkAndComputeOperator(memberNode compilergraph.ModifiableGraphNode, name string) {
name = strings.ToLower(name)
// Verify that the operator matches a known operator.
definition, ok := mb.tdg.operators[name]
if !ok {
mb.tdg.decorateWithError(memberNode, "Unknown operator '%s' defined on type '%s'", name, mb.parent().Name())
return
}
// Some operators are static and some are assignable.
mb.static = definition.IsStatic
mb.readonly = !definition.IsAssignable
// Ensure that the declared return type is equal to that expected.
declaredReturnType := mb.memberType.Generics()[0]
containingType := mb.tdg.NewInstanceTypeReference(mb.parent().AsType())
expectedReturnType := definition.ExpectedReturnType(containingType)
if !mb.skipOperatorChecking {
if !expectedReturnType.IsAny() && !declaredReturnType.IsAny() && declaredReturnType != expectedReturnType {
mb.tdg.decorateWithError(memberNode, "Operator '%s' defined on type '%s' expects a return type of '%v'; found %v",
name, mb.parent().Name(), expectedReturnType, declaredReturnType)
return
}
}
// Decorate the operator with its return type.
var actualReturnType = expectedReturnType
if expectedReturnType.IsAny() {
actualReturnType = declaredReturnType
}
mb.CreateReturnable(mb.sourceNode, actualReturnType)
// Ensure we have the expected number of parameters.
parametersExpected := definition.Parameters
if !mb.skipOperatorChecking {
if mb.memberType.ParameterCount() != len(parametersExpected) {
mb.tdg.decorateWithError(memberNode, "Operator '%s' defined on type '%s' expects %v parameters; found %v",
name, mb.parent().Name(), len(parametersExpected), mb.memberType.ParameterCount())
return
}
}
var memberType = mb.tdg.NewTypeReference(mb.tdg.FunctionType(), actualReturnType)
// Ensure the parameters expected on the operator match those specified.
parameterTypes := mb.memberType.Parameters()
for index, parameterType := range parameterTypes {
if !mb.skipOperatorChecking {
expectedType := parametersExpected[index].ExpectedType(containingType)
if !expectedType.IsAny() && expectedType != parameterType {
mb.tdg.decorateWithError(memberNode, "Parameter '%s' (#%v) for operator '%s' defined on type '%s' expects type %v; found %v",
parametersExpected[index].Name, index, name, mb.parent().Name(),
expectedType, parameterType)
}
}
memberType = memberType.WithParameter(parameterType)
}
// Decorate the member with its type.
memberNode.DecorateWithTagged(NodePredicateMemberType, memberType)
// Decorate the member with its signature.
if definition.IsStatic {
mb.decorateWithSig(mb.tdg.AnyTypeReference())
} else {
mb.decorateWithSig(memberType)
}
}
