示例#1
0
        private void BuildTree(TreeNode parent, EarleyItem current)
        {
            current.SetItemIsProcessed();

            Symbol        lhs       = current.GetRule().GetLeftHandSideOfRule();
            List <Symbol> prev      = current.GetCurrentPrevSymbolList();
            int           setNumber = current.GetSetNumber();

            if (IsEmptyRule(current))
            {
                if (!parent.DoesChildExists(new TreeNode(lhs, setNumber, setNumber)))
                {
                    parent.AddChild(new TreeNode(_grammar.GetNullStringSymbol(), setNumber, setNumber));
                }
            }
            else if (prev.Count == 1 && IsLastSymbolBeforeDotTerminal(prev))
            {
                Symbol symBeforeDot = prev[prev.Count - 1];

                if (!parent.DoesChildExists(new TreeNode(symBeforeDot, setNumber, setNumber)))
                {
                    parent.AddChild(new TreeNode(symBeforeDot, setNumber - 1, setNumber));
                }
            }
            else if (prev.Count == 1 && IsLastSymbolBeforeDotNonTerminal(prev))
            {
                Symbol symBeforeDot = prev[prev.Count - 1];

                TreeNode newNode = new TreeNode(symBeforeDot, current.GetOrignPosition(), setNumber);
                if (!parent.DoesChildExists(newNode))
                {
                    parent.AddChild(newNode);
                }

                current.GetReducerLinks().ForEach(el =>
                {
                    if (el._label == current.GetOrignPosition() && !el._link.IsItemProcessed())
                    {
                        BuildTree(newNode, el._link);
                    }
                });
            }
            else if (IsLastSymbolBeforeDotTerminal(prev))
            {
                Symbol symBeforeDot = prev[prev.Count - 1];

                TreeNode newNode = new TreeNode(symBeforeDot, setNumber - 1, setNumber);
                if (!parent.DoesChildExists(newNode))
                {
                    parent.AddChild(newNode);
                }

                TreeNode newComplexNode = new TreeNode(
                    new DottedRule(current.GetRule(), current.GetRulePosition() - 1),
                    current.GetOrignPosition(),
                    setNumber - 1
                    );
                if (!parent.DoesChildExists(newComplexNode))
                {
                    parent.AddChild(newComplexNode);
                }

                current.GetPredecessorLinks().ForEach(link =>
                {
                    if (link._label == setNumber - 1 && !link._link.IsItemProcessed())
                    {
                        BuildTree(newComplexNode, link._link);
                    }
                });
            }
            else if (IsLastSymbolBeforeDotNonTerminal(prev))
            {
                Symbol symBeforeDot = prev[prev.Count - 1];

                current.GetReducerLinks().ForEach(item =>
                {
                    TreeNode newNode = new TreeNode(symBeforeDot, item._label, setNumber);
                    if (!parent.DoesChildExists(newNode))
                    {
                        parent.AddChild(newNode);
                    }
                    if (!item._link.IsItemProcessed())
                    {
                        BuildTree(newNode, item._link);
                    }

                    TreeNode newComplexNode = new TreeNode(
                        new DottedRule(current.GetRule(), current.GetRulePosition() - 1),
                        current.GetOrignPosition(),
                        item._label
                        );
                    if (!parent.DoesChildExists(newComplexNode))
                    {
                        parent.AddChild(newComplexNode);
                    }
                    current.GetPredecessorLinks().ForEach(predItem =>
                    {
                        if (!predItem._link.IsItemProcessed())
                        {
                            BuildTree(newComplexNode, predItem._link);
                        }
                    });
                });
            }
            ;
        }