/// <summary>
/// Gets the semantic element corresponding to the specified label
/// </summary>
/// <param name="label">The label of an AST node</param>
/// <returns>The corresponding semantic element</returns>
public SemanticElement GetSemanticElementForLabel(TableElemRef label)
{
switch (label.Type)
{
case TableType.Token:
return(tableTokens[label.Index]);
case TableType.Variable:
return(new ASTLabel(tableVariables[label.Index], SymbolType.Variable));
case TableType.Virtual:
return(new ASTLabel(tableVirtuals[label.Index], SymbolType.Virtual));
case TableType.None:
return(new ASTLabel(tableTokens.Terminals[0], SymbolType.Terminal));
}
// This cannot happen
return(null);
}
/// <summary>
/// Gets the symbol corresponding to the specified label
/// </summary>
/// <param name="label">A node label</param>
/// <returns>The corresponding symbol</returns>
public Symbol GetSymbolFor(TableElemRef label)
{
switch (label.Type)
{
case TableType.Token:
return(tableTokens.GetSymbol(label.Index));
case TableType.Variable:
return(tableVariables[label.Index]);
case TableType.Virtual:
return(tableVirtuals[label.Index]);
case TableType.None:
return(tableTokens.Terminals[0]); // terminal epsilon
}
// This cannot happen
return(new Symbol(0, string.Empty));
}
/// <summary>
/// Initializes this node
/// </summary>
/// <param name="label">The node's label</param>
/// <param name="count">The number of children</param>
/// <param name="first">The index of the first child</param>
public Node(TableElemRef label, int count, int first)
{
this.label = label;
this.count = count;
this.first = first;
}
/// <summary>
/// Initializes this node
/// </summary>
/// <param name="label">The node's label</param>
public Node(TableElemRef label)
{
this.label = label;
this.count = 0;
this.first = -1;
}
/// <summary>
/// Gets the value of the given node
/// </summary>
/// <param name="node">A node</param>
/// <returns>The associated value</returns>
public string GetValue(int node)
{
TableElemRef sym = nodes[node].label;
return(sym.Type == TableType.Token ? tableTokens.GetValue(sym.Index) : null);
}
/// <summary>
/// Gets the context in the input of the given node
/// </summary>
/// <param name="node">A node</param>
/// <returns>The context</returns>
public TextContext GetContext(int node)
{
TableElemRef sym = nodes[node].label;
return(sym.Type == TableType.Token ? tableTokens.GetContext(sym.Index) : new TextContext());
}
/// <summary>
/// Gets the span in the input text of the given node
/// </summary>
/// <param name="node">A node</param>
/// <returns>The span in the text</returns>
public TextSpan GetSpan(int node)
{
TableElemRef sym = nodes[node].label;
return(sym.Type == TableType.Token ? tableTokens.GetSpan(sym.Index) : new TextSpan(0, 0));
}