///////////////////////////////////////////////////////////////////////////////////////////////
#region IEnumerable Members
public IEnumerator GetEnumerator()
{
//
// NOTE: Make sure that the variable they supplied is valid before we try to
// use it as the basis of our enumerator.
//
if (interpreter != null)
{
//
// HACK: Handle the global "env" array specially. We must do this because
// our global "env" array has no backing storage (unlike Tcl's) and
// we do not have a trace operation for "get names" or "get names
// and values".
//
if (interpreter.IsEnvironmentVariable(variable))
{
IDictionary environment =
Environment.GetEnvironmentVariables();
if (environment != null)
{
return(environment.Keys.GetEnumerator());
}
else
{
DebugOps.Complain(interpreter, ReturnCode.Error,
"environment variables unavailable");
}
}
else if (interpreter.IsTestsVariable(variable))
{
Result error = null;
StringDictionary tests = interpreter.GetAllTestInformation(
false, ref error);
if (tests != null)
{
return((IEnumerator)tests.Keys.GetEnumerator());
}
else
{
DebugOps.Complain(interpreter, ReturnCode.Error, error);
}
}
else if (interpreter.IsSystemArrayVariable(variable))
{
ReturnCode code;
StringList keys = null;
Result error = null;
code = MarshalOps.GetArrayElementKeys(
interpreter, EntityOps.GetSystemArray(variable),
StringOps.DefaultMatchMode, null, false, ref keys,
ref error);
if (code == ReturnCode.Ok)
{
return(keys.GetEnumerator());
}
else
{
DebugOps.Complain(interpreter, code, error);
}
}
else
{
#if DATA
DatabaseVariable databaseVariable = null;
if (interpreter.IsDatabaseVariable(variable, ref databaseVariable))
{
Result error = null;
ObjectDictionary database = databaseVariable.GetList(
interpreter, true, false, ref error);
if (database != null)
{
return((IEnumerator)database.Keys.GetEnumerator());
}
else
{
DebugOps.Complain(interpreter, ReturnCode.Error, error);
}
}
else
#endif
{
if (variable != null)
{
ElementDictionary arrayValue = variable.ArrayValue;
if ((arrayValue != null) && (arrayValue.Keys != null))
{
return(arrayValue.Keys.GetEnumerator());
}
}
}
}
}
//
// NOTE: While the MSDN documentation does not seem to prohibit returning
// null here, there may be components and/or applications that would
// consider it "bad form"; therefore, we simply return an enumerator
// that does nothing.
//
return(new NullEnumerator <object>());
}