/// <summary>
/// Implementation valid for AccessorCallFrame.
/// The AccessorMemberFrame substitutes it.
/// </summary>
protected override PExpr DoVisit()
{
if (IsPendingOrSignal(ref _left, Expr.Left))
{
return(ReentrantPendingOrSignal(_left));
}
// A visit of the left may have set a result farther in the accessor chain:
// if Result is set, we leave.
if (Result != null)
{
return(new PExpr(Result));
}
Debug.Assert(_left.Result != null, "We are not pending...");
var left = _left.Result;
Debug.Assert(!_result.IsResolved);
if ((_result = left.Visit(this)).IsPendingOrSignal)
{
return(ReentrantPendingOrSignal(_result));
}
return(ReentrantSetResult(_result.Result));
}
public PExpr PendingOrSignal(PExpr sub)
{
Debug.Assert(sub.IsPendingOrSignal);
return(sub.IsResolved ? SetResult(sub.Result) : new PExpr(this, sub.PendingStatus));
}
internal PExpr VisitAndClean()
{
PExpr r = DoVisit();
Debug.Assert( r.Result == _result || (r.Result == null && r.Deferred != null) );
if( _result != null )
{
r = new PExpr( _result );
DoDispose();
}
return r;
}
public PExpr PendingOrSignal( PExpr sub )
{
Debug.Assert( sub.IsPendingOrSignal );
return sub.IsResolved ? SetResult( sub.Result ) : new PExpr( this, sub.DeferredStatus );
}
public bool IsPendingOrSignal( ref PExpr current, Expr e )
{
if( current.IsResolved ) return false;
if( current.IsUnknown ) current = _visitor.VisitExpr( e );
else current = _visitor.StepOver( current.Frame, StepOverKind.InternalStepOver );
return current.IsPendingOrSignal;
}
/// <summary>
/// Updates the status based on the current <see cref="PExpr"/>.
/// </summary>
/// <param name="r">The current <see cref="PExpr"/>.</param>
protected internal virtual void UpdateStatus( PExpr r )
{
_error = (_result = r.Result) as RuntimeError;
_status = ScriptEngineStatus.None;
if( r.AsErrorResult != null ) _status |= ScriptEngineStatus.IsError;
if( r.IsPending )
{
Debug.Assert( r.DeferredStatus != PExpr.DeferredKind.None );
switch( r.DeferredStatus )
{
case PExpr.DeferredKind.Timeout: _status |= ScriptEngineStatus.Timeout; break;
case PExpr.DeferredKind.Breakpoint: _status |= ScriptEngineStatus.Breakpoint; break;
case PExpr.DeferredKind.AsyncCall: _status |= ScriptEngineStatus.AsyncCall; break;
case PExpr.DeferredKind.FirstChanceError: _status |= ScriptEngineStatus.FirstChanceError; break;
default: Debug.Fail( "UpdateStatus" ); break;
}
}
else _status |= ScriptEngineStatus.IsFinished;
}