/// <summary>
/// Initializes a new instance of the <see cref="Parser"/> class.
/// </summary>
/// <param name="language">The language.</param>
/// <param name="scanner">The scanner.</param>
/// <param name="root">The root.</param>
/// <exception cref="Exception">
/// </exception>
public Parser(LanguageData language, Scanner scanner, NonTerminal root)
{
Language = language;
Context = new ParsingContext(this);
Scanner = scanner ?? language.CreateScanner();
if (Scanner != null)
{
Scanner.Initialize(this);
}
else
{
Language.Errors.Add(GrammarErrorLevel.Error, null, "Scanner is not initialized for this grammar");
}
CoreParser = new CoreParser(this);
Root = root;
if (Root == null)
{
Root = Language.Grammar.Root;
InitialState = Language.ParserData.InitialState;
}
else
{
if (Root != Language.Grammar.Root && !Language.Grammar.SnippetRoots.Contains(Root))
{
throw new Exception(string.Format(Resources.ErrRootNotRegistered, root.Name));
}
InitialState = Language.ParserData.InitialStates[Root];
}
}
public static BnfExpression MakeStarRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember, TermListOptions options)
{
bool allowTrailingDelimiter = (options & TermListOptions.AllowTrailingDelimiter) != 0;
if (delimiter == null)
{
//it is much simpler case
listNonTerminal.SetFlag(TermFlags.IsList);
listNonTerminal.Rule = _currentGrammar.Empty | listNonTerminal + listMember;
return(listNonTerminal.Rule);
}
//Note that deceptively simple version of the star-rule
// Elem* -> Empty | Elem | Elem* + delim + Elem
// does not work when you have delimiters. This simple version allows lists starting with delimiters -
// which is wrong. The correct formula is to first define "Elem+"-list, and then define "Elem*" list
// as "Elem* -> Empty|Elem+"
NonTerminal plusList = new NonTerminal(listMember.Name + "+");
plusList.Rule = MakePlusRule(plusList, delimiter, listMember);
plusList.SetFlag(TermFlags.NoAstNode); //to allow it to have AstNodeType not assigned
if (allowTrailingDelimiter)
{
listNonTerminal.Rule = _currentGrammar.Empty | plusList | plusList + delimiter;
}
else
{
listNonTerminal.Rule = _currentGrammar.Empty | plusList;
}
listNonTerminal.SetFlag(TermFlags.IsListContainer);
return(listNonTerminal.Rule);
}
public NonTerminal Star()
{
if (_star != null)
{
return(_star);
}
_star = new NonTerminal(this.Name + "*");
_star.Rule = Grammar.MakeStarRule(_star, this);
return(_star);
}
public NonTerminal Plus()
{
if (_plus != null)
{
return(_plus);
}
_plus = new NonTerminal(this.Name + "+");
_plus.Rule = Grammar.MakePlusRule(_plus, this);
return(_plus);
}
NonTerminal _q, _plus, _star; //cash them
public NonTerminal Q()
{
if (_q != null)
{
return(_q);
}
_q = new NonTerminal(this.Name + "?");
_q.Rule = this | Grammar.CurrentGrammar.Empty;
return(_q);
}
public static BnfExpression MakePlusRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember)
{
if (delimiter == null)
{
listNonTerminal.Rule = listMember | listNonTerminal + listMember;
}
else
{
listNonTerminal.Rule = listMember | listNonTerminal + delimiter + listMember;
}
listNonTerminal.SetFlag(TermFlags.IsList);
return(listNonTerminal.Rule);
}
public static BnfExpression MakeStarRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember)
{
return(MakeStarRule(listNonTerminal, delimiter, listMember, TermListOptions.None));
}
}//method
#endregion
#region MakePlusRule, MakeStarRule methods
public static BnfExpression MakePlusRule(NonTerminal listNonTerminal, BnfTerm listMember)
{
return(MakePlusRule(listNonTerminal, null, listMember));
}
