public EbnfGrammar(EbnfStyle style)
: base("ebnf")
{
Style = style;
DefineCommonNonTerminals = true;
GenerateSpecialSequences();
// terminals
var comment = style.HasFlag(EbnfStyle.BracketComments) ? new GroupParser("(*", "*)") : new GroupParser("/*", "*/");
var ows = -(Terminals.WhiteSpace | comment);
var rws = +(Terminals.WhiteSpace | comment);
var hex_character = ("#x" & +Terminals.HexDigit);
var character = (("\\" & Terminals.AnyChar) | hex_character | Terminals.AnyChar.Except("]")).WithName("character");
var character_range = (character & "-" & character).WithName("character range");
var character_set = ("[" & ~(Parser)"^" & +(character_range | character) & "]").WithName("character set");
var terminal_string = new StringParser { QuoteCharacters = new [] { '\"', '\'', '’' }, Name = "terminal string" };
var special_sequence = ("?" & (+Terminals.AnyChar).Until("?").WithName("name") & "?").WithName("special sequence");
var meta_identifier_terminal = Terminals.Letter & -(Terminals.LetterOrDigit | '_');
var integer = new NumberParser().WithName("integer");
// nonterminals
var definition_list = new RepeatParser(0).WithName("definition list");
var single_definition = new RepeatParser(1).WithName("single definition");
var term = new SequenceParser().WithName("term");
var primary = new AlternativeParser().WithName("primary");
var exception = new UnaryParser("exception");
var factor = new SequenceParser().WithName("factor");
var meta_identifier = new RepeatParser(1).WithName("meta identifier");
var syntax_rule = new SequenceParser().WithName("syntax rule");
var rule_equals = new AlternativeParser().WithName("equals");
Parser meta_reference = meta_identifier;
Parser grouped_sequence = ("(" & ows & definition_list & ows & ")").WithName("grouped sequence");
if (style.HasFlag(EbnfStyle.SquareBracketAsOptional))
{
primary.Add(("[" & ows & definition_list & ows & "]").WithName("optional sequence"));
}
if (!style.HasFlag(EbnfStyle.CardinalityFlags))
{
var repeated_sequence = ("{" & ows & definition_list & ows & "}").WithName("repeated sequence");
primary.Add(repeated_sequence);
}
// rules
meta_identifier.Inner = meta_identifier_terminal;
meta_identifier.Separator = +(Terminals.SingleLineWhiteSpace);
if (!style.HasFlag(EbnfStyle.CommaSeparator))
{
// w3c identifiers must be a single word
meta_identifier.Maximum = 1;
meta_reference = meta_reference.NotFollowedBy(ows & rule_equals);
}
primary.Add(grouped_sequence, meta_reference, terminal_string, special_sequence);
if (style.HasFlag(EbnfStyle.CharacterSets) && !style.HasFlag(EbnfStyle.SquareBracketAsOptional))
{
// w3c supports character sets
primary.Add(hex_character.Named("hex character"));
primary.Add(character_set);
}
if (style.HasFlag(EbnfStyle.NumericCardinality))
factor.Add(~(integer & ows & "*" & ows));
factor.Add(primary);
if (style.HasFlag(EbnfStyle.CardinalityFlags))
{
// w3c defines cardinality at the end of a factor
var flags = style.HasFlag(EbnfStyle.SquareBracketAsOptional) ? "*+" : "?*+";
factor.Add(~(ows & Terminals.Set(flags).WithName("cardinality")));
}
term.Add(factor, ~(ows & "-" & ows & exception));
exception.Inner = term;
single_definition.Inner = term;
single_definition.Separator = style.HasFlag(EbnfStyle.CommaSeparator) ? (Parser)(ows & "," & ows) : ows;
definition_list.Inner = single_definition;
definition_list.Separator = ows & "|" & ows;
rule_equals.Add(style.HasFlag(EbnfStyle.DoubleColonEquals) ? "::=" : "=", ":=");
syntax_rule.Add(meta_identifier, ows, rule_equals, ows, definition_list);
if (style.HasFlag(EbnfStyle.SemicolonTerminator))
syntax_rule.Add(ows, ";"); // iso rules are terminated by a semicolon
var syntax_rules = +syntax_rule;
syntax_rules.Separator = style.HasFlag(EbnfStyle.SemicolonTerminator) ? ows : rws;
Inner = ows & syntax_rules & ows;
AttachEvents();
}
Parser CharacterSet(Match match)
{
var alt = new AlternativeParser();
var inverse = match.Text.StartsWith("[^", StringComparison.Ordinal);
var characters = new List<char>();
foreach (var child in match.Matches.Where(r => r.Name != null))
{
switch (child.Name)
{
case "character range":
var first = Character(child.Matches.First(r => r.Name == "character"));
var last = Character(child.Matches.Last(r => r.Name == "character"));
if (first != null && last != null)
alt.Add(new CharRangeTerminal(first.Value, last.Value) { Inverse = inverse });
break;
case "character":
var character = Character(child);
if (character != null)
characters.Add(character.Value);
break;
default:
throw new FormatException(string.Format("Invalid character set child for text '{0}'", child.Text));
}
}
if (characters.Count > 0)
{
alt.Add(new CharSetTerminal(characters.ToArray()) { Inverse = inverse });
}
if (alt.Items.Count > 1)
return alt;
if (alt.Items.Count > 0)
return alt.Items[0];
return new UnaryParser();
//throw new FormatException(string.Format("Character set has no characters '{0}'", match.Text));
}
public GoldGrammar()
: base("gold")
{
var oldSeparator = Parser.DefaultSeparator;
// Special Terminals
var parameterCh = Terminals.Printable - Terminals.Set("\"'");
var nonterminalCh = Terminals.LetterOrDigit | Terminals.Set("_-. ");
var terminalCh = Terminals.LetterOrDigit | Terminals.Set("_-.");
var literalCh = Terminals.Printable - Terminals.Set('\'');
var setLiteralCh = Terminals.Printable - Terminals.Set("[]'");
var setNameCh = Terminals.Printable - Terminals.Set("{}");
var parameterName = ('"' & (+parameterCh).WithName("value") & '"').Separate();
var nonterminal = ('<' & (+nonterminalCh).WithName("value") & '>').Separate();
var terminal = ((+terminalCh).WithName("terminal") | ('\'' & (-literalCh).WithName("literal") & '\'')).Separate();
var setLiteral = ('[' & +(setLiteralCh.WithName("ch") | '\'' & (-literalCh).WithName("ch") & '\'') & ']').WithName("setLiteral");
var setName = ('{' & (+setNameCh).WithName("value") & '}').WithName("setName");
// Line-Based Grammar Declarations
var comments = new GroupParser("!*", "*!", "!");
var newline = Terminals.Eol;
whitespace = -(Terminals.SingleLineWhiteSpace | comments);
Parser.DefaultSeparator = whitespace;
var nlOpt = -newline;
var nl = +newline | Terminals.End;
// Parameter Definition
var parameterItem = parameterName | terminal | setLiteral | setName | nonterminal;
var parameterItems = +parameterItem;
var parameterBody = parameterItems & -(nlOpt & '|' & parameterItems);
parameter = (parameterName.Named("name") & nlOpt & '=' & parameterBody.WithName("body") & nl).WithName("parameter");
// Set Definition
var setItem = setLiteral | setName;
var setExp = new AlternativeParser { Name = "setExp" };
setExp.Add((setExp & nlOpt & '+' & setItem).WithName("add"),
(setExp & nlOpt & '-' & setItem).WithName("sub"),
setItem);
setDecl = (setName & nlOpt & '=' & setExp & nl).WithName("setDecl");
// Terminal Definition
var regExp2 = new SequenceParser();
var kleeneOpt = (~((Parser)'+' | '?' | '*')).WithName("kleene");
regExpItem = ((setLiteral & kleeneOpt)
| (setName & kleeneOpt)
| (terminal.Named("terminal") & kleeneOpt)
| ('(' & regExp2.Named("regExp2") & ')' & kleeneOpt)).WithName("regExpItem");
var regExpSeq = (+regExpItem).WithName("regExpSeq");
regExp2.Items.Add(regExpSeq);
regExp2.Items.Add(-('|' & regExpSeq));
regExp = (regExpSeq & -(nlOpt & '|' & regExpSeq)).WithName("regExp");
var terminalName = +terminal;
terminalDecl = (terminalName.Named("name") & nlOpt & '=' & regExp & nl).WithName("terminalDecl");
// Rule Definition
symbol = (terminal.Named("terminal") | nonterminal.Named("nonterminal")).WithName("symbol");
handle = (-symbol).WithName("handle");
var handles = handle & -(nlOpt & '|' & handle);
ruleDecl = (nonterminal.Named("name") & nlOpt & "::=" & handles & nl).WithName("ruleDecl");
// Rules
var definitionDecl = parameter | setDecl | terminalDecl | ruleDecl;
var content = -definitionDecl;
this.Inner = nlOpt & content & nlOpt;
Parser.DefaultSeparator = oldSeparator;
AttachEvents();
}