/// <summary>
/// Builds the set of rule definitions that are represented by the given AST
/// </summary>
/// <param name="context">The current context</param>
/// <param name="node">The AST node of a syntactic rule</param>
/// <returns>The set of possible rule definitions</returns>
public RuleBodySet BuildDefinitions(LoaderContext context, ASTNode node)
{
if (node.Symbol.ID == HimeGrammarParser.ID.VariableRuleDefContext)
{
int contextID = grammar.ResolveContext(node.Children[0].Value);
RuleBodySet setInner = BuildDefinitions(context, node.Children[1]);
Variable subVar = grammar.GenerateVariable();
foreach (RuleBody def in setInner)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByChildren, def, contextID));
}
RuleBodySet setVar = new RuleBodySet();
setVar.Add(new RuleBody(subVar));
return(setVar);
}
else if (node.Symbol.ID == HimeGrammarParser.ID.VariableRuleDefSub)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
Variable subVar = grammar.GenerateVariable();
foreach (RuleBody def in setInner)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByEpsilon, def, 0));
}
RuleBodySet setVar = new RuleBodySet();
setVar.Add(new RuleBody(subVar));
return(setVar);
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalOperatorOptional)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
setInner.Insert(0, new RuleBody());
return(setInner);
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalOperatorZeromore)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
Variable subVar = grammar.GenerateVariable();
foreach (RuleBody def in setInner)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByChildren, def, 0));
}
RuleBodySet setVar = new RuleBodySet();
setVar.Add(new RuleBody(subVar));
setVar = RuleBodySet.Multiply(setVar, setInner);
foreach (RuleBody def in setVar)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByChildren, def, 0));
}
setVar = new RuleBodySet();
setVar.Add(new RuleBody());
setVar.Add(new RuleBody(subVar));
return(setVar);
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalOperatorOnemore)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
Variable subVar = grammar.GenerateVariable();
foreach (RuleBody def in setInner)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByChildren, def, 0));
}
RuleBodySet setVar = new RuleBodySet();
setVar.Add(new RuleBody(subVar));
setVar = RuleBodySet.Multiply(setVar, setInner);
foreach (RuleBody def in setVar)
{
subVar.AddRule(new Rule(subVar, TreeAction.ReplaceByChildren, def, 0));
}
setVar = new RuleBodySet();
setVar.Add(new RuleBody(subVar));
return(setVar);
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalOperatorUnion)
{
RuleBodySet setLeft = BuildDefinitions(context, node.Children[0]);
RuleBodySet setRight = BuildDefinitions(context, node.Children[1]);
return(RuleBodySet.Union(setLeft, setRight));
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalTreeActionPromote)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
setInner.ApplyAction(TreeAction.Promote);
return(setInner);
}
else if (node.Symbol.ID == HimeGrammarLexer.ID.TerminalTreeActionDrop)
{
RuleBodySet setInner = BuildDefinitions(context, node.Children[0]);
setInner.ApplyAction(TreeAction.Drop);
return(setInner);
}
else if (node.Symbol.Name == "concat")
{
RuleBodySet setLeft = BuildDefinitions(context, node.Children[0]);
RuleBodySet setRight = BuildDefinitions(context, node.Children[1]);
return(RuleBodySet.Multiply(setLeft, setRight));
}
else if (node.Symbol.Name == "emptypart")
{
RuleBodySet set = new RuleBodySet();
set.Add(new RuleBody());
return(set);
}
return(BuildAtomicDefinition(context, node));
}
