|
|
using Implab;
|
|
|
using System;
|
|
|
using System.Collections.Generic;
|
|
|
using System.Linq;
|
|
|
using System.Text;
|
|
|
using System.Threading.Tasks;
|
|
|
|
|
|
namespace Implab.Parsing {
|
|
|
/// <summary>
|
|
|
/// Базовый абстрактный класс. Грамматика, позволяет формулировать выражения над алфавитом типа <c>char</c>.
|
|
|
/// </summary>
|
|
|
/// <typeparam name="TGrammar"></typeparam>
|
|
|
public abstract class Grammar<TGrammar> where TGrammar: Grammar<TGrammar>, new() {
|
|
|
static TGrammar _instance;
|
|
|
|
|
|
public static TGrammar Instance{
|
|
|
get {
|
|
|
if (_instance == null)
|
|
|
_instance = new TGrammar();
|
|
|
return _instance;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
readonly CharAlphabet m_alphabet = new CharAlphabet();
|
|
|
|
|
|
public CharAlphabet Alphabet {
|
|
|
get { return m_alphabet; }
|
|
|
}
|
|
|
|
|
|
public SymbolToken UnclassifiedToken() {
|
|
|
return new SymbolToken(CharAlphabet.UNCLASSIFIED);
|
|
|
}
|
|
|
|
|
|
public void DefineAlphabet(IEnumerable<char> alphabet) {
|
|
|
Safe.ArgumentNotNull(alphabet, "alphabet");
|
|
|
|
|
|
foreach (var ch in alphabet)
|
|
|
m_alphabet.DefineSymbol(ch);
|
|
|
}
|
|
|
public Token SymbolRangeToken(char start, char end) {
|
|
|
return SymbolToken(Enumerable.Range(start, end - start + 1).Select(x => (char)x));
|
|
|
}
|
|
|
|
|
|
public Token SymbolToken(char symbol) {
|
|
|
return Token.New(TranslateOrAdd(symbol));
|
|
|
}
|
|
|
|
|
|
public Token SymbolToken(IEnumerable<char> symbols) {
|
|
|
Safe.ArgumentNotNull(symbols, "symbols");
|
|
|
|
|
|
return Token.New(TranslateOrAdd(symbols).ToArray());
|
|
|
}
|
|
|
|
|
|
public Token SymbolSetToken(params char[] set) {
|
|
|
return SymbolToken(set);
|
|
|
}
|
|
|
|
|
|
int TranslateOrAdd(char ch) {
|
|
|
var t = m_alphabet.Translate(ch);
|
|
|
if (t == CharAlphabet.UNCLASSIFIED)
|
|
|
t = m_alphabet.DefineSymbol(ch);
|
|
|
return t;
|
|
|
}
|
|
|
|
|
|
IEnumerable<int> TranslateOrAdd(IEnumerable<char> symbols) {
|
|
|
return symbols.Distinct().Select(TranslateOrAdd);
|
|
|
}
|
|
|
|
|
|
int TranslateOrDie(char ch) {
|
|
|
var t = m_alphabet.Translate(ch);
|
|
|
if (t == CharAlphabet.UNCLASSIFIED)
|
|
|
throw new ApplicationException(String.Format("Symbol '{0}' is UNCLASSIFIED", ch));
|
|
|
return t;
|
|
|
}
|
|
|
|
|
|
IEnumerable<int> TranslateOrDie(IEnumerable<char> symbols) {
|
|
|
return symbols.Distinct().Select(TranslateOrDie);
|
|
|
}
|
|
|
|
|
|
public Token SymbolTokenExcept(IEnumerable<char> symbols) {
|
|
|
Safe.ArgumentNotNull(symbols, "symbols");
|
|
|
|
|
|
return Token.New( Enumerable.Range(0, m_alphabet.Count).Except(TranslateOrDie(symbols)).ToArray());
|
|
|
}
|
|
|
|
|
|
protected CDFADefinition BuildDFA(Token lang) {
|
|
|
Safe.ArgumentNotNull(lang, "lang");
|
|
|
|
|
|
var dfa = new CDFADefinition(m_alphabet);
|
|
|
|
|
|
var builder = new DFABuilder();
|
|
|
|
|
|
lang.Accept( builder );
|
|
|
|
|
|
builder.BuildDFA(dfa);
|
|
|
if (dfa.InitialStateIsFinal)
|
|
|
throw new ApplicationException("The specified language contains empty token");
|
|
|
|
|
|
return dfa.Optimize();
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
//protected abstract TGrammar CreateInstance();
|
|
|
}
|
|
|
|
|
|
|
|
|
}
|
|
|
|
