Hi, Mauricio, sorry for hijacking your thread. : )
I have one question about handling or parsing decimal places. I noticed that Haskell doesn't accept values starting with just the point, e.g., .50 or .01. I suppose that's abuse of notation in the first place (and I'm guilty of it), but I often receive datasets that have numbers written that way. Do we have this behavior to avoid ambiguity with the dot operator? For example: > .1 <interactive>:1:0: parse error on input `.' > read ".1" :: Float *** Exception: Prelude.read: no parse And then: > let (.) = (+) > 1 .1 2 I often end up writing a function that will add a leading zero when it's missing for decimal places, before feeding a string to read. Is there a better way of handling this? Thanks, Paulo On Thu, Sep 18, 2008 at 7:13 AM, Mauricio <[EMAIL PROTECTED]> wrote: >>> Agree about the answer, not about the question. The >>> correct one would be "is it possible to change haskell >>> syntax to support the international notation (...) >> >> For some sense of "possible", the answer is clearly yes. >> However, it is perhaps misleading to call commas >> "THE international notation". (...) You might as >> well ask "is it possible to change Haskell syntax to >> support only the *real* Arabic digits ... for ... >> numbers". (... + evindences that there isn't one > >> single standard) > > Well, utf-8 strings seemed to me a good way to initialize > variables, and we could, for instance use something > like "[1,2,3,4]" to initialize other kinds of lists > besides the standard one. One example I got from gtk2hs > are marked-up text on labels. So, I actually thought > we could add support for arabic and japanese digits, > and any other ways we get without ambiguities (continued > fractions, I would like, and I also liked the idea of > the raised dot). > > Well, after all the comments, I'm convinced changing > the Show and Read classes are not the way to go. But > I'll think of something like a InitializableByUFT8String > class, and I'll advertize it here if I ever get > something usable and interesting. > > Thanks for your comments, > Maurício > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
