Hi,
2008/4/7 Paul Keir
I'm using buildExpressionParser, and I'd like to use alphanumeric operator characters. I get an (unexpected "a") error though. With a test string like "-a" if "a" is used in any of the "reservedOpNames". I'm aiming for the Fortran operators like ".and.".
...
reservedOp checks to make sure that whatever it parses isn't immediately followed by another valid operator character (the idea being, I think, that then whoever wrote the string being parsed probably meant for that other longer operator to be one token). This causes your error, since it can't parse the reservedOp "~", and "~a" itself is not anything. You'll notice that, for example, "~ a" parses just fine. I don't seen any perfect solution. If you want to use the token and expression modules in this way, you'll have to redefine your operators so as not to intersect with your valid identifiers. Alternatively, you can roll your own token parsers (though parsec does what it does for good reasons, so you might see some unexpected behavior). Or you could just mandate that operators must be followed by a space. Good luck! --Chris Casinghino