public bool ExclusivelyPrefix(string name)
{
if (IsOperator(name))
{
return(true);
}
PrologOperator op = GetOperator(name);
if (op != null)
{
return(op.PostfixPrecedence == -1);
}
return(false);
}
public void AddPostfixOperator(string name, bool right, int precedence)
{
PrologOperator op = null;
if (IsOperator(name))
{
op = GetOperator(name);
op.PostfixPrecedence = precedence;
op.IsPostfixAssociative = right;
}
else
{
op = new PrologOperator(name, 0, precedence, 0);
op.IsPrefixAssociative = right;
_operatorTable.Add(name, op);
}
}
public void AddPostfixOperator(string name, bool right, int precedence)
{
PrologOperator op = null;
if (IsOperator(name))
{
op = GetOperator(name);
op.PostfixPrecedence = precedence;
op.IsPostfixAssociative = right;
}
else
{
op = new PrologOperator(name, 0, precedence, 0);
op.IsPrefixAssociative = right;
_operatorTable.Add(name, op);
}
}
public void AddInfixOperator(string name, bool left, bool right, int precedence)
{
PrologOperator op = null;
if (IsOperator(name))
{
op = GetOperator(name);
op.InfixPrecedence = precedence;
op.IsInfixLeftAssociative = left;
op.IsInfixRightAssociative = right;
}
else
{
op = new PrologOperator(name, 0, 0, precedence);
op.IsInfixLeftAssociative = left;
op.IsInfixRightAssociative = right;
_operatorTable.Add(name, op);
}
}
public void AddInfixOperator(string name, bool left, bool right, int precedence)
{
PrologOperator op = null;
if (IsOperator(name))
{
op = GetOperator(name);
op.InfixPrecedence = precedence;
op.IsInfixLeftAssociative = left;
op.IsInfixRightAssociative = right;
}
else
{
op = new PrologOperator(name, 0, 0, precedence);
op.IsInfixLeftAssociative = left;
op.IsInfixRightAssociative = right;
_operatorTable.Add(name, op);
}
}
private BinaryTree Right(int n, int m, ref BinaryTree result)
{
switch (_scanner.Lookahead.Kind)
{
case PrologToken.DOT:
case PrologToken.RPAREN:
case PrologToken.RBRACKET:
return(result);
case PrologToken.LPAREN:
case PrologToken.LBRACKET:
_errors.Add(new PrologCompilerError("P0007", "Unexpected open brackets or parenthsis", "", false, _scanner.Current.Line, _scanner.Current.Column));
return(result);
case PrologToken.COMMA:
if (n >= 1000 && m <= 1000)
{
m = 1000;
_scanner.Next();
result = new BinaryTree(",", result, Term(m));
if (n > m)
{
Right(n, m, ref result);
}
}
return(result);
case PrologToken.ATOM:
PrologOperator laOp = _operators.GetOperator(_scanner.Lookahead.StringValue);
if (laOp != null)
{
if (laOp.IsPostfix &&
n >= laOp.PostfixPrecedence &&
m <= laOp.PostfixLeftPrecedence)
{
_scanner.Next();
if (_operators.IsOperator(_scanner.Current.StringValue))
{
PrologOperator o = _operators.GetOperator(_scanner.Current.StringValue);
if (o.IsInfix &&
n >= o.InfixPrecedence &&
m <= o.InfixLeftPrecedence)
{
switch (_scanner.Lookahead.Kind)
{
case PrologToken.LPAREN:
case PrologToken.LBRACKET:
result = new BinaryTree(o.Name, result, Term(o.InfixRightPrecedence));
m = o.InfixPrecedence;
Right(n, m, ref result);
break;
case PrologToken.COMMA:
case PrologToken.RPAREN:
case PrologToken.RBRACKET:
result = new BinaryTree(_scanner.Current.StringValue, result);
m = o.InfixPrecedence;
Right(n, m, ref result);
break;
case PrologToken.ATOM:
if (_operators.IsOperator(_scanner.Lookahead.StringValue))
{
if (_operators.ExclusivelyPrefix(_scanner.Lookahead.StringValue))
{
result = new BinaryTree(_scanner.Lookahead.StringValue, result, Term(_operators.GetOperator(_scanner.Lookahead.StringValue).PrefixRightPrecedence));
m = o.InfixPrecedence;
Right(n, m, ref result);
break;
}
}
else
{
result = new BinaryTree(_scanner.Lookahead.StringValue, result, null);
m = _operators.GetOperator(_scanner.Lookahead.StringValue).InfixPrecedence;
Right(n, m, ref result);
break;
}
break;
}
}
else
{
result = new BinaryTree(_scanner.Current.StringValue, result);
m = _operators.GetOperator(_scanner.Current.StringValue).InfixPrecedence;
Right(n, m, ref result);
}
}
break;
}
else if (laOp.IsInfix && n >= laOp.InfixPrecedence && m <= laOp.InfixLeftPrecedence)
{
_scanner.Next();
int p = _operators.GetOperator(_scanner.Current.StringValue).InfixPrecedence;
int t = _operators.GetOperator(_scanner.Current.StringValue).InfixRightPrecedence;
result = new BinaryTree(_scanner.Current.StringValue, result, Term(t));
m = p;
Right(n, m, ref result);
break;
}
}
else
{
return(result);
}
break;
}
return(result);
}
public BinaryTree Term(int n)
{
int m = 0;
BinaryTree ast = null;
_scanner.Next();
switch (_scanner.Current.Kind)
{
case PrologToken.LPAREN:
ast = Term(1200);
_scanner.Next();
if (_scanner.Current.Kind != PrologToken.RPAREN)
{
_errors.Add(new PrologCompilerError("P0003", "Expected ) after term", "", false, _scanner.Current.Line, _scanner.Current.Column));
}
break;
// Handle list terms here...
case PrologToken.LBRACKET:
ArrayList listArguments = new ArrayList();
// Peek after [ token
if (_scanner.Lookahead.Kind == PrologToken.RBRACKET)
{
_scanner.Next();
// return a nil atom: []
ast = new BinaryList(); // empty list
break;
}
listArguments.Add(Term(999));
_scanner.Next();
// if , is encountered
while (_scanner.Current.Kind == PrologToken.COMMA)
{
listArguments.Add(Term(999));
_scanner.Next();
}
if (_scanner.Current.Kind == PrologToken.LIST_SEP)
{
listArguments.Add(Term(999));
_scanner.Next();
}
else
{
listArguments.Add(new BinaryList());
}
if (_scanner.Current.Kind != PrologToken.RBRACKET)
{
_errors.Add(new PrologCompilerError("P0004", "Unterminated list, expected ]", "", false, _scanner.Current.Line, _scanner.Current.Column));
}
int i = listArguments.Count - 1;
BinaryList list = new BinaryList((BinaryTree)listArguments[i - 1], (BinaryTree)listArguments[i]);
i -= 2;
while (i > -1)
{
list = new BinaryList((BinaryTree)listArguments[i--], list);
}
ast = list;
break;
case PrologToken.RPAREN:
case PrologToken.RBRACKET:
case PrologToken.COMMA:
case PrologToken.DOT:
_errors.Add(new PrologCompilerError("P0005", "Unexpected closure of term", "", false, _scanner.Current.Line, _scanner.Current.Column));
return(null);
case PrologToken.ATOM:
case PrologToken.VARIABLE:
string atomName = _scanner.Current.StringValue;
if (_scanner.Lookahead.Kind == PrologToken.LPAREN)
{
ArrayList arguments = new ArrayList();
_scanner.Next();
arguments.Add(Term(1200));
_scanner.Next();
while (_scanner.Current.Kind == PrologToken.COMMA)
{
arguments.Add(Term(1200));
_scanner.Next();
}
if (_scanner.Current.Kind != PrologToken.RPAREN)
{
_errors.Add(new PrologCompilerError("P0005", "Unexpected closure of term", "", false, _scanner.Current.Line, _scanner.Current.Column));
return(null);
}
ast = new BinaryTree(atomName, arguments);
break;
}
if (_operators.IsOperator(_scanner.Current.StringValue))
{
PrologOperator op = _operators.GetOperator(_scanner.Current.StringValue);
if (op.IsPrefix)
{
// prefix operator
if (n < op.PrefixPrecedence)
{
ParserError("prefix precedence error", _scanner.Current.Line, _scanner.Current.Column);
return(null);
}
switch (_scanner.Lookahead.Kind)
{
case PrologToken.LPAREN:
case PrologToken.LBRACKET:
ast = new BinaryTree(op.Name, Term(op.PrefixRightPrecedence));
m = op.PrefixPrecedence;
Right(n, m, ref ast);
break;
case PrologToken.RPAREN:
case PrologToken.RBRACKET:
case PrologToken.DOT:
case PrologToken.LIST_SEP:
if (n < m)
{
_errors.Add(new PrologCompilerError("P0006", "Unexpected atom '" + _scanner.Lookahead.StringValue + "'", "", false, _scanner.Current.Line, _scanner.Current.Column));
return(null);
}
ast = new BinaryTree(_scanner.Current.StringValue);
Right(n, m, ref ast);
break;
case PrologToken.ATOM:
if (_operators.IsOperator(_scanner.Lookahead.StringValue))
{
PrologOperator atomOp = _operators.GetOperator(_scanner.Lookahead.StringValue);
if (atomOp.IsInfix && m <= atomOp.InfixLeftPrecedence)
{
if (n < m)
{
ParserError("n < m", _scanner.Lookahead.Line, _scanner.Current.Column);
return(null);
}
ast = new BinaryTree(_scanner.Lookahead.StringValue);
Right(n, m, ref ast);
break;
}
else if (atomOp.IsPostfix && m <= atomOp.PostfixLeftPrecedence)
{
if (n < m)
{
ParserError("n < m", _scanner.Current.Line, _scanner.Current.Column);
return(null);
}
ast = new BinaryTree(_scanner.Current.StringValue);
Right(n, m, ref ast);
break;
}
// Just added on 6/23/2006. Might not fix anything.
else
{
ast = new BinaryTree(_scanner.Current.StringValue, null, Term(op.InfixRightPrecedence));
m = op.PrefixPrecedence;
Right(n, m, ref ast);
break;
}
}
else
{
ast = new BinaryTree(_scanner.Current.StringValue, null, Term(op.InfixRightPrecedence));
m = op.PrefixPrecedence;
Right(n, m, ref ast);
}
break;
default:
ParserError("Unknown internal error", _scanner.Current.Line, _scanner.Current.Column);
return(null);
}
}
}
else
{
ast = new BinaryTree(_scanner.Current.StringValue);
}
break;
default:
ParserError("Unknown internal error", _scanner.Current.Line, _scanner.Current.Column);
return(null);
}
Right(n, m, ref ast);
return(ast);
}
