private IPythonType TryDetermineReturnValue()
{
var annotationType = Eval.GetTypeFromAnnotation(FunctionDefinition.ReturnAnnotation);
if (!annotationType.IsUnknown())
{
// Annotations are typically types while actually functions return
// instances unless specifically annotated to a type such as Type[T].
// TODO: try constructing argument set from types. Consider Tuple[_T1, _T2] where _T1 = TypeVar('_T1', str, bytes)
var t = annotationType.CreateInstance(ArgumentSet.Empty(FunctionDefinition.ReturnAnnotation, Eval));
// If instance could not be created, such as when return type is List[T] and
// type of T is not yet known, just use the type.
var instance = t.IsUnknown() ? (IMember)annotationType : t;
_overload.SetReturnValue(instance, true); _overload.SetReturnValue(instance, true);
}
else
{
// Check if function is a generator
var suite = FunctionDefinition.Body as SuiteStatement;
var yieldExpr = suite?.Statements.OfType <ExpressionStatement>().Select(s => s.Expression as YieldExpression).ExcludeDefault().FirstOrDefault();
if (yieldExpr != null)
{
// Function return is an iterator
var yieldValue = Eval.GetValueFromExpression(yieldExpr.Expression) ?? Eval.UnknownType;
var returnValue = new PythonGenerator(Eval.Interpreter, yieldValue);
_overload.SetReturnValue(returnValue, true);
}
}
return(annotationType);
}
private void TryAddBase(List <IPythonType> bases, Arg arg)
{
// We cheat slightly and treat base classes as annotations.
var b = Eval.GetTypeFromAnnotation(arg.Expression);
if (b != null)
{
var t = b.GetPythonType();
bases.Add(t);
t.AddReference(Eval.GetLocationOfName(arg.Expression));
}
}
public override void Evaluate()
{
var stub = SymbolTable.ReplacedByStubs.Contains(Target) ||
_function.DeclaringModule.ModuleType == ModuleType.Stub ||
Module.ModuleType == ModuleType.Specialized;
using (Eval.OpenScope(_function.DeclaringModule, FunctionDefinition, out _)) {
// Process annotations.
var annotationType = Eval.GetTypeFromAnnotation(FunctionDefinition.ReturnAnnotation);
if (!annotationType.IsUnknown())
{
// Annotations are typically types while actually functions return
// instances unless specifically annotated to a type such as Type[T].
var instance = annotationType.CreateInstance(annotationType.Name, ArgumentSet.Empty);
_overload.SetReturnValue(instance, true);
}
else
{
// Check if function is a generator
var suite = FunctionDefinition.Body as SuiteStatement;
var yieldExpr = suite?.Statements.OfType <ExpressionStatement>().Select(s => s.Expression as YieldExpression).ExcludeDefault().FirstOrDefault();
if (yieldExpr != null)
{
// Function return is an iterator
var yieldValue = Eval.GetValueFromExpression(yieldExpr.Expression) ?? Eval.UnknownType;
var returnValue = new PythonGenerator(Eval.Interpreter, yieldValue);
_overload.SetReturnValue(returnValue, true);
}
}
DeclareParameters(!stub);
// Do process body of constructors since they may be declaring
// variables that are later used to determine return type of other
// methods and properties.
var ctor = _function.Name.EqualsOrdinal("__init__") || _function.Name.EqualsOrdinal("__new__");
if (ctor || annotationType.IsUnknown() || Module.ModuleType == ModuleType.User)
{
// Return type from the annotation is sufficient for libraries and stubs, no need to walk the body.
FunctionDefinition.Body?.Walk(this);
// For libraries remove declared local function variables to free up some memory.
var optionsProvider = Eval.Services.GetService <IAnalysisOptionsProvider>();
if (Module.ModuleType != ModuleType.User && optionsProvider?.Options.KeepLibraryLocalVariables != true)
{
((VariableCollection)Eval.CurrentScope.Variables).Clear();
}
}
}
Result = _function;
}
public void HandleAnnotatedExpression(ExpressionWithAnnotation expr, IMember value)
{
if (expr?.Annotation == null)
{
return;
}
var variableType = Eval.GetTypeFromAnnotation(expr.Annotation);
// If value is null, then this is a pure declaration like
// x: List[str]
// without a value. If value is provided, then this is
// x: List[str] = [...]
HandleTypedVariable(variableType, value, expr.Expression);
}
public void EvaluateClass()
{
// Open class scope chain
using (Eval.OpenScope(Module, _classDef, out var outerScope)) {
var instance = Eval.GetInScope(_classDef.Name, outerScope);
if (!(instance?.GetPythonType() is PythonClassType classInfo))
{
if (instance != null)
{
// TODO: warning that variable is already declared of a different type.
}
return;
}
// Evaluate inner classes, if any
EvaluateInnerClasses(_classDef);
_class = classInfo;
// Set bases to the class.
var bases = new List <IPythonType>();
foreach (var a in _classDef.Bases.Where(a => string.IsNullOrEmpty(a.Name)))
{
// We cheat slightly and treat base classes as annotations.
var b = Eval.GetTypeFromAnnotation(a.Expression);
if (b != null)
{
var t = b.GetPythonType();
bases.Add(t);
t.AddReference(Eval.GetLocationOfName(a.Expression));
}
}
_class.SetBases(bases);
// Declare __class__ variable in the scope.
Eval.DeclareVariable("__class__", _class, VariableSource.Declaration);
ProcessClassBody();
}
}
private void DeclareParameters(bool declareVariables)
{
// For class method no need to add extra parameters, but first parameter type should be the class.
// For static and unbound methods do not add or set anything.
// For regular bound methods add first parameter and set it to the class.
var parameters = new List <ParameterInfo>();
var skip = 0;
if (_self != null && _function.HasClassFirstArgument())
{
var p0 = FunctionDefinition.Parameters.FirstOrDefault();
if (p0 != null && !string.IsNullOrEmpty(p0.Name))
{
// Actual parameter type will be determined when method is invoked.
// The reason is that if method might be called on a derived class.
// Declare self or cls in this scope.
if (declareVariables)
{
Eval.DeclareVariable(p0.Name, new PythonInstance(_self), VariableSource.Declaration, p0.NameExpression);
}
// Set parameter info.
var pi = new ParameterInfo(Ast, p0, _self, null, false);
parameters.Add(pi);
skip++;
}
}
// Declare parameters in scope
IMember defaultValue = null;
for (var i = skip; i < FunctionDefinition.Parameters.Length; i++)
{
var isGeneric = false;
var p = FunctionDefinition.Parameters[i];
if (!string.IsNullOrEmpty(p.Name))
{
IPythonType paramType = null;
if (p.DefaultValue != null)
{
defaultValue = Eval.GetValueFromExpression(p.DefaultValue);
// If parameter has default value, look for the annotation locally first
// since outer type may be getting redefined. Consider 's = None; def f(s: s = 123): ...
paramType = Eval.GetTypeFromAnnotation(p.Annotation, out isGeneric, LookupOptions.Local | LookupOptions.Builtins);
// Default value of None does not mean the parameter is None, just says it can be missing.
defaultValue = defaultValue.IsUnknown() || defaultValue.IsOfType(BuiltinTypeId.NoneType) ? null : defaultValue;
if (paramType == null && defaultValue != null)
{
paramType = defaultValue.GetPythonType();
}
}
// If all else fails, look up globally.
paramType = paramType ?? Eval.GetTypeFromAnnotation(p.Annotation, out isGeneric) ?? Eval.UnknownType;
var pi = new ParameterInfo(Ast, p, paramType, defaultValue, isGeneric);
if (declareVariables)
{
DeclareParameter(p, pi);
}
parameters.Add(pi);
}
}
_overload.SetParameters(parameters);
}
