| public AddError ( string message, SourceLocation location ) : void | ||
| message | string | |
| location | SourceLocation | |
| return | void | |
// expression : term [ OR term ]...
private Expression Expression()
{
var exp = Term();
if (exp != null)
{
while (!_tokenzier.IsEndOfFile)
{
using (var lookahead = _tokenzier.BeginLookahead())
{
var op = _tokenzier.NextToken();
if (op != null && op.Kind == TokenKind.OR)
{
var sourceLocation = _tokenzier.CurrentLocation;
var right = Term();
if (right != null)
{
lookahead.Accept();
exp = new LogicalBindaryExpression(exp, right, LogicalOperator.OR);
}
else
{
_context.AddError("Missing right operand for operator " + op.Kind + ".", sourceLocation);
break;
}
}
else
{
break;
}
}
}
}
return(exp);
}
private Token Number()
{
SkipWhitespaces();
if (_source.IsEndOfFile)
{
return(null);
}
Token token = null;
var state = NumberParseState.InPrimaryPart;
using (var lookahead = _source.BeginLookahead())
{
_buffer.Clear();
var startPosition = _source.Position;
while (!_source.IsEndOfFile)
{
var ch = _source.Peek();
if (char.IsDigit(ch))
{
if (state == NumberParseState.BeginFractionalPart)
{
state = NumberParseState.InFractionalPart;
}
_buffer.Append(ch);
_source.MoveNext();
if (_source.IsEndOfFile && (state == NumberParseState.InPrimaryPart || state == NumberParseState.InFractionalPart))
{
lookahead.Accept();
token = new Token(_buffer.ToString(), TokenKind.Number, new SourceLocation(startPosition));
break;
}
}
else if (ch == '.')
{
state = NumberParseState.BeginFractionalPart;
_buffer.Append(ch);
_source.MoveNext();
}
else
{
if (state == NumberParseState.BeginFractionalPart)
{
_context.AddError("Missing fractional part.", new SourceLocation(_source.Position));
break;
}
else
{
lookahead.Accept();
token = new Token(_buffer.ToString(), TokenKind.Number, new SourceLocation(startPosition));
break;
}
}
}
}
return(token);
}