public virtual void PostWalk(NonlocalStatement node)
{
}
// NonlocalStatement
public virtual bool Walk(NonlocalStatement node)
{
return(true);
}
// NonlocalStatement
public override bool Walk(NonlocalStatement node)
{
return(Contains(node));
}
public override void PostWalk(NonlocalStatement node)
{
}
// NonlocalStatement
public override bool Walk(NonlocalStatement node)
{
return(false);
}
public override bool Walk(NonlocalStatement node)
{
foreach (var nameNode in node.Names)
{
var n = nameNode.Name;
if (n == null)
{
continue;
}
// Check current scope for conflicting variable
var assignedLocal = false;
if (_currentScope.TryGetVariable(n, out var conflict))
{
// conflict?
switch (conflict.Kind)
{
case VariableKind.Global:
ReportSyntaxError("name '{0}' is nonlocal and global".FormatUI(n), node);
break;
case VariableKind.Local:
assignedLocal = true;
ReportSyntaxWarning(
"name '{0}' is assigned to before nonlocal declaration".FormatUI(n),
node
);
break;
case VariableKind.Parameter:
ReportSyntaxError(
"name '{0}' is a parameter and nonlocal".FormatUI(n),
node);
break;
case VariableKind.Nonlocal:
// OK to reassign as long as kind is the same.
// Consider example from Python test grammar:
// nonlocal x
// nonlocal x, y
assignedLocal = true;
break;
}
}
// Check for the name being referenced previously. If it has been, issue warning.
if (_currentScope.IsReferenced(n) && !assignedLocal)
{
ReportSyntaxWarning(
"name '{0}' is used prior to nonlocal declaration".FormatUI(n),
node);
}
if (conflict == null)
{
// no previously definied variables, add it to the current scope
_currentScope.CreateVariable(n, VariableKind.Nonlocal);
}
_currentScope.AddNonLocalVariable(nameNode);
nameNode.AddVariableReference(GlobalScope, BindReferences, Reference(n));
}
return(true);
}
