/// <summary>
/// Create a new sentence where string in the given list is treated as a separate terminal
/// </summary>
/// <param name="tokens"></param>
/// <returns></returns>
public static Sentence FromTokens(IEnumerable <string> tokens)
{
var l = new List <Terminal>();
foreach (var token in tokens)
{
// l.Add(Terminal.Of(c.ToString()));
l.Add(Terminal.Of(token));
}
return(new Sentence(l));
}
/// <summary>
/// Turns a string like
/// <X> -> <X> 'a' <X>
/// into a production.
/// Nonterminals must be surrounded by angled brackets, terminals must be surrounded by single quotes, and everything must be separated by spaces.
/// </summary>
/// <param name="s"></param>
/// <returns></returns>
public static Production Production(string s)
{
var match = ProductionRegex.Match(s);
if (!match.Success)
{
throw new Exception("Didn't find valid string");
}
var lhsMatch = match.Groups["lhs"];
var ntMatch = match.Groups["nt"];
var tMatch = match.Groups["t"];
var weightMatch = match.Groups["weight"];
if (!lhsMatch.Success)
{
throw new Exception("Didn't find LHS");
}
double weight;
if (!double.TryParse(weightMatch.Value, out weight))
{
weight = 1.0;
}
var rhsList = new SortedList <int, Word>();
foreach (Capture capture in ntMatch.Captures)
{
var word = Nonterminal.Of(capture.Value);
rhsList.Add(capture.Index, word);
}
foreach (Capture capture in tMatch.Captures)
{
var word = Terminal.Of(capture.Value);
rhsList.Add(capture.Index, word);
}
var rhs = new Sentence(rhsList.Values);
var lhs = Nonterminal.Of(lhsMatch.Value);
var retval = new Production(lhs, rhs, weight);
return(retval);
}
public void RandomTesting()
{
var randg = new GrammarGenerator();
int _maxNonterminals = 8;
int _maxProductions = 8;
int _maxTerminals = 20;
int _step = 1;
for (int numProductions = 0; numProductions < _maxProductions; numProductions += _step)
{
for (int numNonterminals = 1; numNonterminals < _maxNonterminals; numNonterminals += _step)
{
for (int numTerminals = 1; numTerminals < _maxTerminals; numTerminals += _step)
{
var range = Enumerable.Range(0, numTerminals);
var terminals = new List <Terminal>(range.Select((x) => Terminal.Of("x" + x)));
Console.WriteLine("{0}, {1}, {2}", numNonterminals, numProductions, numTerminals);
var rg = randg.NextCNF(numNonterminals, numProductions, terminals);
TestGrammar(rg);
}
}
}
}
