public IParseTree <TToken, TRule> Parse(IList <Token <TToken> > tokens, ITextIndexHelper translator)
{
if (!this.configCompleted)
{
throw ParserConfigurationException.NotCompleted();
}
var parseTree = this.rulesByType[this.rootType].TryParse(tokens, 0, this.rulesByType);
if (parseTree.IsError || parseTree.NextTokenIndex != tokens.Count)
{
if (parseTree.MaxMatchedNextTokenIndex == tokens.Count)
{
throw new EndOfTokensException();
}
if (parseTree.MaxMatchedNextTokenIndex < 0 || parseTree.MaxMatchedNextTokenIndex > tokens.Count)
{
throw new ApplicationException("An unexpected error was encountered.");
}
throw UnexpectedTokenException.For(tokens[parseTree.MaxMatchedNextTokenIndex], translator);
}
return(parseTree.TreeItems);
}
public Parser <TToken, TRule> Rule(
TRule type,
params Action <IParserRuleConfigurator <TToken, TRule> >[] options)
{
if (this.configCompleted)
{
throw ParserConfigurationException.AlreadyCompleted();
}
if (!this.rulesByType.TryGetValue(type, out var rule))
{
rule = new RuleDefinition(type);
this.rulesByType.Add(type, rule);
}
foreach (var option in options)
{
option(rule);
}
return(this);
}
public Parser <TToken, TRule> WithRoot(TRule type)
{
if (this.configCompleted)
{
throw ParserConfigurationException.AlreadyCompleted();
}
this.rootType = type;
this.configCompleted = true;
// Validate the configuration to ensure
// no expected rules are missing
var validated = new HashSet <TRule>();
var toValidate = new Stack <TRule>();
toValidate.Push(type);
while (toValidate.Count != 0)
{
var checking = toValidate.Pop();
if (!this.rulesByType.TryGetValue(checking, out var checkingDefinition))
{
throw ParserConfigurationException.RuleNotDefined(checking.ToString());
}
validated.Add(checking);
foreach (var dependency in checkingDefinition
.DirectlyDependsOn()
.Where(o => !validated.Contains(o))
.Distinct())
{
toValidate.Push(dependency);
}
}
return(this);
}
