//not_test: 'not' not_test | comparison
private Expression ParseNotTest()
{
if (MaybeEat(TokenKind.KeywordNot)) {
string proceeding = _tokenWhiteSpace;
var start = GetStart();
Expression ret = new UnaryExpression(JOperator.Not, ParseNotTest());
if (_verbatim) {
AddPreceedingWhiteSpace(ret, proceeding);
}
ret.SetLoc(start, GetEnd());
return ret;
} else {
return ParseComparison();
}
}
// factor: ('+'|'-'|'~') factor | power
private Expression ParseFactor()
{
var start = _lookahead.Span.Start;
Expression ret;
switch (PeekToken().Kind) {
case TokenKind.Add:
NextToken();
string posWhiteSpace = _tokenWhiteSpace;
ret = new UnaryExpression(JOperator.Pos, ParseFactor());
if (_verbatim) {
AddPreceedingWhiteSpace(ret, posWhiteSpace);
}
break;
case TokenKind.Subtract:
NextToken();
ret = FinishUnaryNegate();
break;
case TokenKind.Twiddle:
NextToken();
string twiddleWhiteSpace = _tokenWhiteSpace;
ret = new UnaryExpression(JOperator.Invert, ParseFactor());
if (_verbatim) {
AddPreceedingWhiteSpace(ret, twiddleWhiteSpace);
}
break;
default:
return ParsePower();
}
ret.SetLoc(start, GetEnd());
return ret;
}