You can use fix to take some data that might not be right (say, an integer that might actually be a string) and "fix" it by applying read-string: (fix "10" string? read-string). to-fix returns a function you can use to fix things.
On Wednesday, February 20, 2013 12:06:36 AM UTC-8, Laurent PETIT wrote: > > Hello, > > Why the names fix / to-fix ? > > 2013/2/20 Alan Malloy <al...@malloys.org <javascript:>>: > > Useful has functions that do this and more: fix or to-fix, according to > > taste. Your iffn is just the three-argument case of to-fix: (def magnify > > (to-fix pos? inc dec)). But fix and to-fix accept more or fewer > arguments as > > well, so that (fix x pos? inc) is like (if (pos? x) (inc x) x), and > (to-fix > > tall? shorten thin? fatten) is (fn [x] (cond (tall? x) (shorten x) > (thin? x) > > (fatten x) :else x)). > > > > Basically both of these functions look through their clause pairs and > apply > > the first transform whose test matches. fix takes its "focus" argument > > immediately, while to-fix returns a lambda that performs the requested > > operation. > > > > > > On Tuesday, February 19, 2013 9:53:57 PM UTC-8, James MacAulay wrote: > >> > >> Sometimes I find myself writing code like this: > >> > >> (defn magnify [n] (if (pos? n) (inc n) (dec n))) > >> > >> ...and I want to get rid of all those "n"s. I've looked for a macro > like > >> this, but couldn't find it, so I wrote it: > >> > >> https://gist.github.com/jamesmacaulay/4993062 > >> > >> Using that, I could re-write the above like this: > >> > >> (def magnify (iffn pos? inc dec)) > >> > >> I can imagine a condfn macro, too: > >> > >> (def magnify2 (condfn pos? inc > >> neg? dec > >> :else identity) > >> > >> Has this kind of conditional function composition been explored much? I > >> couldn't find anything like it in the standard library, but maybe I > wasn't > >> looking hard enough. > >> > >> Cheers, > >> James > > > > -- > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to clo...@googlegroups.com<javascript:> > > Note that posts from new members are moderated - please be patient with > your > > first post. > > To unsubscribe from this group, send email to > > clojure+u...@googlegroups.com <javascript:> > > For more options, visit this group at > > http://groups.google.com/group/clojure?hl=en > > --- > > You received this message because you are subscribed to the Google > Groups > > "Clojure" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to clojure+u...@googlegroups.com <javascript:>. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
