public ParseNode GetAndMove(ParseNodeTag tag)
{
ParseNode node = Items[_index++];
if (node.Tag != tag)
{
throw new SyntaxException("Unexpected parse node: {0} (expected: {1})", node.Tag, tag);
}
return(node);
}
private Func <ParseNode> GetFlattenLeftRecurtion(
ParseNodeTag nodeTag,
Func <ParseNode> childFactory,
Func <bool> continueCondition)
{
return(() =>
{
var root = new ParseNode(nodeTag);
do
{
root.AddChild(childFactory());
}while (continueCondition());
return root;
});
}
private Func <ParseNode> GetBinaryOperation(
ParseNodeTag nodeTag,
Func <ParseNode> childFactory,
Func <bool> breakCondition)
{
Func <ParseNode, ParseNode, ParseNode> nodeFactory = (leftOp, rightOp) =>
{
return(new ParseNode(nodeTag)
.AddChild(leftOp)
.AddChild(rightOp.Children.GetAndMove())
.AddChild(rightOp.Children.GetAndMove()));
};
Func <ParseNode> rightChildFactory = () =>
{
return(new ParseNode(nodeTag)
.AddChild(Terminal())
.AddChild(childFactory()));
};
return(GetLeftRecurtion(nodeFactory, childFactory, rightChildFactory, breakCondition));
}
public ParseNode Wrap(ParseNodeTag tag)
{
return(new ParseNode(tag, this));
}
public ParseNode(ParseNodeTag tag, Token terminal, IEnumerable <ParseNode> children)
{
Tag = tag;
Token = terminal;
Children = new ParseNodeCollection(children);
}
public ParseNode(ParseNodeTag tag, params ParseNode[] children)
: this(tag, default(Token), children)
{
}
public bool Check(ParseNodeTag tag)
{
return((_index >= 0 && _index < Items.Count) &&
Items[_index].Tag == tag);
}