//protected Grammar mGrammar;
public Rule(Grammar aGrammar, Lexema aLex)
{
if (aLex == null || aLex.Type != LexemType.NotTerminal)
{
throw new GrammarSyntaxException("Rule Name expected");
}
Name = aLex.Text;
aLex = aLex.Next();
if (aLex != null && aLex.Type == LexemType.Terminal)
{
mSeparator = aLex.Text;
aLex = aLex.Next();
}
if (aLex == null || aLex.Type != LexemType.IsSign)
{
throw new GrammarSyntaxException(":= expected");
}
aLex = aLex.Next();
PhraseParser lParser = new PhraseParser(aGrammar, aLex);
RightSide = lParser.ParseRule();
}
/// <summary>
/// Parses Acc to array or seq ([], .)
/// and ListTrans call e.g. Param.Count()
/// </summary>
/// <param Name="lBaseAcc"></param>
/// <returns>true - access found, continue chain of accs, false - stop parsing</returns>
private bool Acc(ref IExpr lBaseAcc)
{
//arr
if (null != lex)
{
if (lex.Text == "[")
{
lex = lex.Next();
IExpr lIndExpr = Expr();
ExpectSign("]");
lBaseAcc = new AccessArray(mGrammar, (Access)lBaseAcc, lIndExpr);
return(true);
}
//struct
if (lex.Text == ".")
{
lex = lex.Next();
string lFieldName = lex.Text;
lex = lex.Next();
if (lex != null && lex.Type == LexemType.LeftBr)
{
// call of ListTrans
lex = lex.Next();
lBaseAcc = (IExpr)TransCall1((Access)lBaseAcc, lFieldName);
}
else
{
lBaseAcc = new AccessSeq(mGrammar, lBaseAcc, lFieldName);
return(true);
}
}
}
return(false);
}
/// <summary>
/// Can return ExprInt, ExprDouble, ExprString or variable
/// 1, 1.2, "aaa", %VARNAME%
/// </summary>
/// <returns></returns>
private IExpr ParseExprValue()
{
IExpr lRes;
if (lex.Type == LexemType.Terminal)
{
lRes = new ExprString(lex.Text);
lex = lex.Next();
}
else
{
string lIntStr = lex.Text;
lRes = ParseIntValue();
//check if doble
if (lex != null && lex.Text == ".")
{
lex = lex.Next();
CheckType(LexemType.IntNumber);
Double d =
double.Parse(lIntStr
+ Thread.CurrentThread.CurrentCulture.NumberFormat.NumberDecimalSeparator
+ lex.Text);
lex = lex.Next();
lRes = new ExprDouble(d);
}
}
return(lRes);
}
private IExpr MulExpr()
{
IExpr lRes;
if (lex.Type == LexemType.LeftBr)
{
lex = lex.Next();
lRes = Expr();
Expect(LexemType.RightBr, ")");
}
else if (lex.Type == LexemType.NotTerminal)
{
string lName = lex.Text;
lex = lex.Next();
if (lex != null && lex.Type == LexemType.LeftBr)
{
lex = lex.Next();
lRes = (IExpr)TransCall1(null, lName);
}
else
{
IExpr lAcc = new Access(mGrammar, lName);
Accs(ref lAcc);
return(lAcc);
}
}
else
{
lRes = ParseExprValue();
}
return(lRes);
}
private void Quant(ref IPhrase aPhr)
{
// look for quantifier here
if (lex != null && (lex.Text == "{" ||
lex.Text == "*" ||
lex.Text == "+" ||
lex.Text == "?"))
{
ExprInt lMin = null, lMax = null;
//{1..5}
if (lex.Text == "{")
{
lex = lex.Next();
lMin = ParseIntValue();
if (lex.Text == ".")
{
lex = lex.Next();
ExpectSign(".");
if (lex.Text == "*")
{
lMax = new ExprInt(Int32.MaxValue);
}
else
{
lMax = ParseIntValue();
}
}
else
{
lMax = lMin;
}
ExpectSign("}");
}
else if (lex.Text == "*")
{
lMin = new ExprInt(0);
lMax = new ExprInt(int.MaxValue);
lex = lex.Next();
}
else if (lex.Text == "+")
{
lMin = new ExprInt(1);
lMax = new ExprInt(int.MaxValue);
lex = lex.Next();
}
else if (lex.Text == "?")
{
lMin = new ExprInt(0);
lMax = new ExprInt(1);
lex = lex.Next();
}
else
{
throw new GrammarSyntaxException("Недолжно быть. Неподдерживаемый знак после нетерминала " + lex.Text);
}
QuantifiedPhrase lQuant = new QuantifiedPhrase(mGrammar, aPhr, lMin, lMax);
aPhr = lQuant;
}
}
//Returns simple Nonterminal symbol or TransCallPhrase
private IPhrase TransCall()
{
string Name = lex.Text;
lex = lex.Next();
if (lex != null && lex.Type == LexemType.LeftBr)
{
lex = lex.Next();
return(TransCall1(null, Name));
}
return(NonTerminal.Create(mGrammar, null, Name)); //TODO!!!
}
private void AsAlias(ref IPhrase aPhr)
{
if (null != lex)
{
if (lex.Type == LexemType.NotTerminal && lex.Text.ToLower() == "as")
{
lex = lex.Next();
CheckType(LexemType.NotTerminal);
aPhr.Alias = lex.Text;
lex = lex.Next();
}
}
}
//Seq := T | NT | "(",Phrase,")"
private IPhrase Seq()
{
if (lex == null)
{
throw new GrammarSyntaxException("unexpected end of rule");
}
IPhrase lPhr;
if (lex.Type == LexemType.LeftBr)
{
lex = lex.Next();
lPhr = ParsePhrase();
Expect(LexemType.RightBr, ")");
Quant(ref lPhr);
}
else if (lex.Type == LexemType.Sign && lex.Text == "[")
{
lex = lex.Next();
lPhr = new QuantifiedPhrase(mGrammar, ParsePhrase(), 0, 1);
ExpectSign("]");
}
else if (lex.Type == LexemType.Sign && lex.Text == "{")
{
lex = lex.Next();
lPhr = new QuantifiedPhrase(mGrammar, ParsePhrase());
ExpectSign("}");
}
else if (lex.Type == LexemType.Sign && lex.Text == "<")
{
lex = lex.Next();
if (lex.Type != LexemType.NotTerminal)
{
throw new GrammarSyntaxException("Name expected");
}
string lName = lex.Text;
lex = lex.Next();
ExpectSign(">");
lPhr = PlaceHolderAssign(lName);
Quant(ref lPhr);
}
else if (lex.Text == "#")
{
lex = lex.Next();
lPhr = Expr();
}
else
{
//терминальный или не терминальный
if (lex.Type == LexemType.Terminal)
{
lPhr = new Terminal(mGrammar, lex.Text);
lex = lex.Next();
}
else if (lex.Type == LexemType.NotTerminal)
{
lPhr = TransCall();
}
else
{
throw new GrammarSyntaxException("Terminal or Non-Terminal symbol expected");
}
Quant(ref lPhr);
}
return(lPhr);
}
