/// <summary>
///
/// </summary>
/// <param name="text"></param>
public Tree Parse(string text)
{
_scanner = new Scanner(text);
_tree = new Tree();
Token token = this.NextToken();
if (token == Token.EndOfFile)
return _tree;
this.CheckStartableToken(token);
while (token != Token.EndOfFile)
{
if (Parser.IsConstTocken(token))
ParseConst();
else if (_tree._isStart &&
((token == Token.Subtract) || (token == Token.Add)))
{
Constant constant = new Constant((int)0);
_tree.AddOperand(constant);
BinaryOp bo = BinaryOp.CreateOp(token);
_tree.AddOperator(bo);
}
else if (Parser.IsBinaryOp(token))
ParseBinaryOp();
else if (Parser.IsUnaryOp(token))
ParseUnaryOp();
else
{
switch (token)
{
case Token.Identifier:
ParseIdentifier();
break;
case Token.LeftIndexer:
this.ParseIndexer();
break;
case Token.RightIndexer:
_tree.Pop('[');
break;
case Token.ConditionalIf:
ParseConditional();
break;
case Token.ConditionalSemicolon:
ParseConditionalSemicolon();
break;
case Token.Member:
ParseMember();
break;
case Token.LeftParen:
if (_tree._top.Expression is MemberOp)
{
MemberOp memberOp = (MemberOp)_tree._top.Expression;
if (memberOp.IsFunction)
throw new ParserException("()()not allowed");
memberOp.IsFunction = true;
}
this._tree.Push('(');
break;
case Token.RightParen:
_tree.Pop('(');
break;
case Token.Comma:
this._tree.Pop(',');
this._tree.Push(',');
break;
default:
throw BuildException(Error.InternalError);
}
}
token = this.NextToken();
}
_tree.Complete();
return _tree;
}
void ParseConst()
{
Token token = this.PeekToken();
if (!Parser.IsCanFollowConst(token))
{
throw this.BuildException(Error.BinaryCommaRightParenRightIndexerExpected);
}
Constant expr = new Constant(_current.value);
_tree.AddOperand( expr);
}