/// <summary>
/// Moves to the next token if the current token is of the given type, othervise does nothing
/// </summary>
/// <param name="lexrule"></param>
public void SkipIf(Lexrule lexrule)
{
if (Current.type == lexrule)
{
Next();
}
}
/// <summary>
/// Moves to the next token and asserts that it is of the given type
/// </summary>
/// <param name="lexrule"></param>
/// <returns></returns>
public Token AssertNext(Lexrule lexrule)
{
var r = Next();
Assert(lexrule);
return(r);
}
/// <summary>
/// throws a parser exception if the current tokens type is not the specified value
/// </summary>
/// <param name="lexrule"></param>
public void Assert(Lexrule lexrule)
{
if (Current.type != lexrule)
{
throw new ParserException("TokneReader assertion failed");
}
}
internal IRule GetRuleWithModifier(string name)
{
/*
* rule?
* rule*
* rule+
* 'rule'
*/
bool sw(string c) => name.StartsWith(c);
bool ew(string c) => name.EndsWith(c);
if (ew("?") || ew("*") || ew("+"))
{
return(ModifiedRule.CreateModifiedRule(GetRule(name.TrimEnd('?', '*', '+')), name.Last()));
}
if (sw("'") && ew("'"))
{
var r = new Lexrule("inline" + inlineId++, name.Trim('\''));
lexer.InsertRule(0, r);
return(r);
}
return(GetRule(name));
}
private void initializeRules()
{
var thisType = this.GetType();
var fields = thisType.GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public).Where(x => x.IsDefined(typeof(RuleAttribute), false));
// init lexer:
var lexrules = new List <Lexrule>();
var lexrulesProps = fields.Where(x => x.FieldType == typeof(Lexrule));
foreach (var item in lexrulesProps)
{
var at = item.GetCustomAttributes(typeof(RuleAttribute), false)[0] as RuleAttribute;
var skipat = item.GetCustomAttributes(typeof(SkipAttribute), false).FirstOrDefault();
var lr = new Lexrule(item.Name, skipat != null, at.pattern);
lr.createNode = at.createNode;
lexrules.Add(lr);
item.SetValue(this, lr);
}
lexer = new Lexer(lexrules);
// init parserules:
var parserulesProps = fields.Where(x => x.FieldType == typeof(Parserule));
foreach (var item in parserulesProps)
{
var at = item.GetCustomAttributes(typeof(RuleAttribute), false)[0] as RuleAttribute;
var rule = new Parserule(item.Name, at.pattern);
rule.createNode = at.createNode;
parserules.Add(rule);
item.SetValue(this, rule);
}
foreach (var item in parserules)
{
item.Initialize(this);
}
}
public void InsertRule(int index, Lexrule rule) => rules.Insert(index, rule);
public void AddRule(Lexrule rule) => rules.Add(rule);
internal Token(Lexrule rule, string value)
{
type = rule; this.value = value;
}
