public INode Reduce(IRule rule, INodeContext <INode> page)
{
var ruleName = ((Value)page.Get(0)).Text;
var result = new ProtoRule("Ref", rule => rule.Ref(ruleName));
result.RuleName = ruleName;
return(result);
}
private void DefineReferencedRulesAsDummies(IGrammarBuilder <INode> grammar, ProtoRule rule, HashSet <string> defined)
{
foreach (var child in rule.Children)
{
if (child.DisplayText == "Ref" && child.RuleName != null && !defined.Contains(child.RuleName))
{
defined.Add(child.RuleName);
grammar.DefineRule(child.RuleName, new MockRule(child.RuleName));
}
DefineReferencedRulesAsDummies(grammar, child, defined);
}
}
public INode Reduce(IRule rule, INodeContext <INode> page)
{
// sequence with a single item => no sequence needed
if (page.Count == 1)
{
return(page.Get(0));
}
var result = new ProtoRule(nameof(Core.Rules.Sequence), rule => new Core.Rules.Sequence(rule.RuleName, rule.All()));
result.AddChildren(page.GetAll().Of <ProtoRule>());
return(result);
}
public INode Reduce(IRule rule, INodeContext <INode> page)
{
// choice with a single item => no choice needed
if (page.Count == 1)
{
return(page.Get(0));
}
var result = new ProtoRule(nameof(Core.Rules.Choice), rule => new Core.Rules.Choice(rule.RuleName, rule.All()));
// filter out the "|" values
result.AddChildren(page.GetAll().Of <ProtoRule>());
return(result);
}
private string?RefNamePropagation(ProtoRule rule, int level = 0)
{
foreach (var child in rule.Children)
{
var name = RefNamePropagation(child, level + 1);
if (name != null)
{
if (child.RefName != null)
{
throw new Exception($"Cannot propagate ref name inside of named RuleRef. {child.DisplayText} is already named {child.RefName}");
}
child.RefName = name;
}
}
if (level > 0)
{
var namedChildren = rule.Children.Where(r => r.RefName != null).ToList();
if (namedChildren.Select(c => c.RefName).Distinct().Count() > 1)
{
throw new Exception($"Cannot propagate multiple distinct ref names inside of {rule.DisplayText}");
}
else if (namedChildren.Count > 0)
{
var name = namedChildren.First().RefName;
if (name != IRuleRef.LiftRefName)
{
foreach (var child in namedChildren)
{
child.RefName = IRuleRef.LiftRefName;
}
return(name);
}
}
}
return(null);
}
public INode Reduce(IRule rule, INodeContext <INode> page)
{
var prefix = page.Get("prefix").Optional <Value>()?.Text;
var range = page.Get("suffix").Optional <Ast.Range>();
var atom = page.Get("atom").Single <ProtoRule>();
var result = atom;
if (range != null)
{
result = new ProtoRule(nameof(Repeat), rule => new Repeat(rule.RuleName, rule.Single(), range.Min, range.Max));
result.Children.Add(atom);
atom = result;
}
if (prefix != null)
{
result = _prefixMap[prefix]();
result.Children.Add(atom);
}
return(result);
}
