public async Task HandleTupleAssignmentAsync(TupleExpression lhs, Expression rhs, IMember value, CancellationToken cancellationToken = default) {
cancellationToken.ThrowIfCancellationRequested();
if (rhs is TupleExpression tex) {
var returnedExpressions = tex.Items.ToArray();
var names = lhs.Items.OfType<NameExpression>().Select(x => x.Name).ToArray();
for (var i = 0; i < Math.Min(names.Length, returnedExpressions.Length); i++) {
if (returnedExpressions[i] != null && !string.IsNullOrEmpty(names[i])) {
var v = await Eval.GetValueFromExpressionAsync(returnedExpressions[i], cancellationToken);
if (v != null) {
Eval.DeclareVariable(names[i], v, returnedExpressions[i]);
}
}
}
return;
}
// Tuple = 'tuple value' (such as from callable). Transfer values.
if (value is IPythonCollection seq) {
var types = seq.Contents.Select(c => c.GetPythonType()).ToArray();
var expressions = lhs.Items.OfType<NameExpression>().ToArray();
var names = expressions.Select(x => x.Name).ToArray();
for (var i = 0; i < Math.Min(names.Length, types.Length); i++) {
if (names[i] != null && types[i] != null) {
var instance = types[i].CreateInstance(null, Eval.GetLoc(expressions[i]), ArgumentSet.Empty);
Eval.DeclareVariable(names[i], instance, expressions[i]);
}
}
}
}
public async Task <bool> HandleTryExceptAsync(TryStatement node, CancellationToken cancellationToken = default)
{
await node.Body.WalkAsync(Walker, cancellationToken);
foreach (var handler in node.Handlers.MaybeEnumerate())
{
if (handler.Test != null && handler.Target is NameExpression nex)
{
var value = await Eval.GetValueFromExpressionAsync(handler.Test, cancellationToken);
Eval.DeclareVariable(nex.Name, value, nex);
}
await handler.Body.WalkAsync(Walker, cancellationToken);
}
if (node.Finally != null)
{
await node.Finally.WalkAsync(Walker, cancellationToken);
}
if (node.Else != null)
{
await node.Else.WalkAsync(Walker, cancellationToken);
}
return(false);
}
public override async Task <bool> WalkAsync(ReturnStatement node, CancellationToken cancellationToken = default)
{
var value = await Eval.GetValueFromExpressionAsync(node.Expression, cancellationToken);
if (value != null)
{
_overload.AddReturnValue(value);
}
return(true); // We want to evaluate all code so all private variables in __new__ get defined
}
public override async Task <bool> WalkAsync(ReturnStatement node, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
var value = await Eval.GetValueFromExpressionAsync(node.Expression, cancellationToken);
if (!value.IsUnknown())
{
_result = value;
return(false);
}
return(true);
}
public async Task HandleWithAsync(WithStatement node, CancellationToken cancellationToken = default) {
cancellationToken.ThrowIfCancellationRequested();
foreach (var item in node.Items.Where(x => x.Variable != null)) {
var contextManager = await Eval.GetValueFromExpressionAsync(item.ContextManager, cancellationToken);
var cmType = contextManager.GetPythonType();
var enter = cmType?.GetMember(node.IsAsync ? @"__aenter__" : @"__enter__")?.GetPythonType<IPythonFunctionType>();
if (enter != null) {
var context = await Eval.GetValueFromFunctionTypeAsync(enter, null, null, cancellationToken);
if (item.Variable is NameExpression nex && !string.IsNullOrEmpty(nex.Name)) {
Eval.DeclareVariable(nex.Name, context, Eval.GetLoc(item));
}
}
}
}
public override async Task EvaluateAsync(CancellationToken cancellationToken = default)
{
if (SymbolTable.ReplacedByStubs.Contains(Target))
{
return;
}
cancellationToken.ThrowIfCancellationRequested();
// Process annotations.
var annotationType = await Eval.GetTypeFromAnnotationAsync(FunctionDefinition.ReturnAnnotation, cancellationToken);
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, Eval.GetLoc(FunctionDefinition), 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 = await Eval.GetValueFromExpressionAsync(yieldExpr.Expression, cancellationToken) ?? Eval.UnknownType;
var returnValue = new PythonGenerator(Eval.Interpreter, yieldValue);
_overload.SetReturnValue(returnValue, true);
}
}
using (Eval.OpenScope(FunctionDefinition, out _)) {
await DeclareParametersAsync(cancellationToken);
if (annotationType.IsUnknown() || Module.ModuleType == ModuleType.User)
{
// Return type from the annotation is sufficient for libraries
// and stubs, no need to walk the body.
if (FunctionDefinition.Body != null && Module.ModuleType != ModuleType.Specialized)
{
await FunctionDefinition.Body.WalkAsync(this, cancellationToken);
}
}
}
}
public async Task HandleForAsync(ForStatement node, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
var iterable = await Eval.GetValueFromExpressionAsync(node.List, cancellationToken);
var iterator = (iterable as IPythonIterable)?.GetIterator();
if (iterator == null)
{
// TODO: report that expression does not evaluate to iterable.
}
var value = iterator?.Next ?? Eval.UnknownType;
switch (node.Left)
{
case NameExpression nex:
// for x in y:
Eval.DeclareVariable(nex.Name, value, Eval.GetLoc(node.Left));
break;
case TupleExpression tex:
// x = [('abc', 42, True), ('abc', 23, False)]
// for some_str, some_int, some_bool in x:
var names = tex.Items.OfType <NameExpression>().Select(x => x.Name).ToArray();
if (value is IPythonIterable valueIterable)
{
var valueIterator = valueIterable.GetIterator();
foreach (var n in names)
{
Eval.DeclareVariable(n, valueIterator?.Next ?? Eval.UnknownType, Eval.GetLoc(node.Left));
}
}
else
{
// TODO: report that expression yields value that does not evaluate to iterable.
}
break;
}
if (node.Body != null)
{
await node.Body.WalkAsync(Walker, cancellationToken);
}
}
public override async Task <bool> WalkAsync(AssignmentStatement node, CancellationToken cancellationToken = default)
{
var value = await Eval.GetValueFromExpressionAsync(node.Right, cancellationToken);
foreach (var lhs in node.Left)
{
switch (lhs)
{
case MemberExpression memberExp when memberExp.Target is NameExpression nameExp1: {
if (_function.DeclaringType.GetPythonType() is PythonClassType t && nameExp1.Name == "self")
{
t.AddMembers(new[] { new KeyValuePair <string, IMember>(memberExp.Name, value) }, true);
}
continue;
}
case NameExpression nameExp2 when nameExp2.Name == "self":
return(true); // Don't assign to 'self'
}
}
return(await base.WalkAsync(node, cancellationToken));
}
private async Task DeclareParameterAsync(Parameter p, int index, ParameterInfo pi, CancellationToken cancellationToken = default)
{
IPythonType paramType;
// If type is known from annotation, use it.
if (pi != null && !pi.Type.IsUnknown() && !pi.Type.IsGenericParameter())
{
// TODO: technically generics may have constraints. Should we consider them?
paramType = pi.Type;
}
else
{
var defaultValue = await Eval.GetValueFromExpressionAsync(p.DefaultValue, cancellationToken) ?? Eval.UnknownType;
paramType = defaultValue.GetPythonType();
if (!paramType.IsUnknown())
{
pi?.SetDefaultValueType(paramType);
}
}
Eval.DeclareVariable(p.Name, paramType, p.NameExpression);
}
private async Task DeclareParametersAsync(CancellationToken cancellationToken = default)
{
// 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.
Eval.DeclareVariable(p0.Name, _self, p0.NameExpression);
// Set parameter info.
var pi = new ParameterInfo(Ast, p0, _self);
pi.SetType(_self);
parameters.Add(pi);
skip++;
}
}
// Declare parameters in scope
for (var i = skip; i < FunctionDefinition.Parameters.Length; i++)
{
cancellationToken.ThrowIfCancellationRequested();
var p = FunctionDefinition.Parameters[i];
if (!string.IsNullOrEmpty(p.Name))
{
// 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): ...
IPythonType paramType = null;
if (p.DefaultValue != null)
{
paramType = await Eval.GetTypeFromAnnotationAsync(p.Annotation, cancellationToken, LookupOptions.Local | LookupOptions.Builtins);
if (paramType == null)
{
var defaultValue = await Eval.GetValueFromExpressionAsync(p.DefaultValue, cancellationToken);
if (!defaultValue.IsUnknown())
{
paramType = defaultValue.GetPythonType();
}
}
}
// If all else fails, look up globally.
paramType = paramType ?? await Eval.GetTypeFromAnnotationAsync(p.Annotation, cancellationToken);
var pi = new ParameterInfo(Ast, p, paramType);
await DeclareParameterAsync(p, i, pi, cancellationToken);
parameters.Add(pi);
}
}
_overload.SetParameters(parameters);
}
public async Task HandleAssignmentAsync(AssignmentStatement node, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
var value = await Eval.GetValueFromExpressionAsync(node.Right, cancellationToken);
if (value.IsUnknown())
{
Log?.Log(TraceEventType.Verbose, $"Undefined value: {node.Right.ToCodeString(Ast).Trim()}");
}
if (value?.GetPythonType().TypeId == BuiltinTypeId.Ellipsis)
{
value = Eval.UnknownType;
}
if (node.Left.FirstOrDefault() is TupleExpression lhs)
{
// Tuple = Tuple. Transfer values.
var texHandler = new TupleExpressionHandler(Walker);
await texHandler.HandleTupleAssignmentAsync(lhs, node.Right, value, cancellationToken);
return;
}
foreach (var expr in node.Left.OfType <ExpressionWithAnnotation>())
{
// x: List[str] = [...]
await HandleAnnotatedExpressionAsync(expr, value, cancellationToken);
}
foreach (var ne in node.Left.OfType <NameExpression>())
{
if (Eval.CurrentScope.NonLocals[ne.Name] != null)
{
Eval.LookupNameInScopes(ne.Name, out var scope, LookupOptions.Nonlocal);
if (scope != null)
{
scope.Variables[ne.Name].Value = value;
}
else
{
// TODO: report variable is not declared in outer scopes.
}
continue;
}
if (Eval.CurrentScope.Globals[ne.Name] != null)
{
Eval.LookupNameInScopes(ne.Name, out var scope, LookupOptions.Global);
if (scope != null)
{
scope.Variables[ne.Name].Value = value;
}
else
{
// TODO: report variable is not declared in global scope.
}
continue;
}
Eval.DeclareVariable(ne.Name, value, Eval.GetLoc(ne));
}
}
