What John said. This said, an old idea for the DF design would be to include additional metadata for each column, which could include things like an arbitrary Unicode pretty name that's not restricted to valid variable name strings.
On Fri, May 2, 2014 at 10:08 AM, John Myles White <[email protected]>wrote: > I would discourage using <R> as the name of a column in a DataFrame. > > Part of the reason we’re using symbols now is that it will encourage > people to use column names that are valid Julia variable names. If you > stick to valid variable names, you’ll always be able to use metaprogramming > tools like those employed to generate formulas for GLM’s. > > — John > > On May 2, 2014, at 1:03 AM, Tomas Lycken <[email protected]> wrote: > > :"<R>" for symbol("<R>") makes sense to me, so if it's not in the way of > anything else, I'm all for it. > > And yeah, :"<R>" == "<R>" returns true, so I don't see how this could > really make something impossible to do, which is possible today. I guess if > there's code out that quotes literal strings like that it'll break, but I > doubt that there's a lot of it... I have no idea how such a change would be > implemented, though, so I'm afraid I won't be of much help making it happen. > > // T > > On Friday, May 2, 2014 9:50:14 AM UTC+2, Stefan Karpinski wrote: >> >> We talked at some point about making :"<R>" syntax for symbol("<R>") and >> requiring something like :("<R>") to express the fairly useless operation >> of quoting the string "<R>" (this is useless because the result is just the >> string "<R>"). Barring some problem with this that I'm not thinking of, I'd >> be in favor of such a change. >> >> >> On Fri, May 2, 2014 at 3:14 AM, Tomas Lycken <[email protected]> wrote: >> >>> Sorry to hijack the thread, but since I stumbled over this problem >>> myself (in the same context) and didn't know about the `symbol("A")` >>> syntax, this seems like an appropriate place to ask: >>> >>> In the dataframe I was working with, I had one column named "R", and >>> another which I wanted to name "<R>". Using :R was no problem, but it's not >>> possible to refer to :<R> at all. (Try it in the REPL - it parses it as an >>> incomplete expression, and if I add something after I get an error "R not >>> defined"...) >>> >>> I think it's cool that it's possible to define symbols from arbitrary >>> strings using e.g. `symbol("<R>")`, but it's kind of clunky that you can't >>> refer to them with the colon syntax once they're defined. Is there a way >>> around this, or do I have to simply "deal with it"? =) >>> >>> // T >>> >>> >>> On Thursday, May 1, 2014 7:24:05 AM UTC+2, Ivar Nesje wrote: >>>> >>>> Symbols in Julia is a special form of strings that are faster for some >>>> operations (like comparisons) and much slower for others. Julia uses >>>> symbols internally to represent variable names. >>>> >>>> You create a symbol from a string with the symbol("A") function, or the >>>> :A syntax. >>>> >>> >> >
