/**
* Generate the next word of the language based on the specified alphabet, axiom and rewrite rules.
* Rewrite the CurrentWord
*
*
* public override String Rewrite()
* {
* StringBuilder NextGeneration = new StringBuilder();
* for (int i = 0; i < CurrentString.Length; i++)
* {
* Char NextSymbol = CurrentString[i];
* ProductionRule RewriteRule = GetProductionRule(NextSymbol, i, CurrentString);
* if(RewriteRule!=null)
* NextGeneration.Append(RewriteRule.Rewrite(NextSymbol, i, CurrentString));
* else//if a rewrite rule is missing, rewrite the symbol with itself:
* NextGeneration.Append(NextSymbol);
* }
* AddString(NextGeneration.ToString());
*
* return NextGeneration.ToString();
* }*/
public override Word Rewrite()
{
Word nextWord = new Word();
for (int i = 0; i < currentWord.GetSize(); i++)
{
Symbol predecessor = currentWord.SymbolAt(i);
Word successor = null;
foreach (ProductionRule productionRule in ProductionRules)
{
successor = productionRule.Rewrite(predecessor, i, currentWord);
if (successor != null)//A Rule for that symbol is found!
{
nextWord.Append(successor);
break;
}
}
//there was no Rule which rewrote the predecessor symbol
//As a matter of convention, if there is no rule
// for a character, that character is left unchanged.
if (successor == null)
{
nextWord.Append(predecessor);
}
}
AddWord(nextWord);
return(nextWord);
}
public Word ParseWord(String wordSource)
{
Word word = new Word();
//using the lexer to parse the character sequence into symbols
ITokenStream tokenStream = lexer.Analyze(wordSource);
Token nextToken = null;
while ((nextToken = tokenStream.NextToken()) != null)
{
word.Append(Symbol.valueOf(nextToken.ToString()));//in this case a token = a symbol
}
return(word);
}
