/// <summary>
/// Creates variables which are defined in a parent scope and used by a child scope.
/// </summary>
private void CreateChildReferencedVariables(AstGenerator ag, MSAst.Expression parentContext, List<MSAst.Expression> init) {
MSAst.Expression localTuple = null;
foreach (KeyValuePair<SymbolId, PythonReference> kv in _childReferences) {
// a child scope refers to this closure value but we don't refer
// to it directly.
int index = ag.TupleIndex(kv.Value.PythonVariable);
Type tupleType = ag.GetParentTupleType();
if (localTuple == null) {
// pull the tuple from the context once
localTuple = ag.HiddenVariable(tupleType, "$parentClosureTuple");
init.Add(
MSAst.Expression.Assign(
localTuple,
MSAst.Expression.Convert(
MSAst.Expression.Call(
typeof(PythonOps).GetMethod("GetClosureTupleFromContext"),
parentContext
),
tupleType
)
)
);
}
ag.ReferenceVariable(kv.Value.PythonVariable, index, localTuple, false);
}
}
/// <summary>
/// Creates variables which are defined in a parent scope and accessed in this scope.
/// </summary>
private void CreateReferencedVariables(AstGenerator ag, List<MSAst.Expression> init, bool emitDictionary, bool needsLocals) {
MSAst.Expression localTuple = null;
foreach (KeyValuePair<SymbolId, PythonReference> kv in _references) {
PythonVariable var = kv.Value.PythonVariable;
if (var == null || var.Scope == this) {
continue;
}
if ((var.Kind == VariableKind.Local || var.Kind == VariableKind.Parameter) && !var.Scope.IsGlobal) {
// closed over local, we need to pull in the closure variable
Type tupleType = ag.GetParentTupleType();
int index = ag.TupleIndex(var);
localTuple = EnsureLocalTuple(ag, init, localTuple, tupleType);
// get the closure cell from the tuple
MSAst.Expression tuplePath = localTuple;
foreach (var v in MutableTuple.GetAccessPath(tupleType, index)) {
tuplePath = MSAst.Expression.Property(tuplePath, v);
}
MSAst.ParameterExpression pe = ag.HiddenVariable(typeof(ClosureCell), SymbolTable.IdToString(var.Name));
init.Add(MSAst.Expression.Assign(pe, tuplePath));
ag.SetLocalLiftedVariable(var, new ClosureExpression(var, pe, null));
if (emitDictionary) {
ag.ReferenceVariable(var, index, localTuple, needsLocals);
}
}
}
}
