In general, I find that multiple arguments types for a function confusing. If dotimes is going to take multiple types it should be a multifn. That seems to imply a performance hit. I think Clojure wisely does not (or rarely does not?) allow for multiple types to be passed into a function.
On top of that it's trivial to produce a macro on top of dotimes that does what you want that doesn't spend time checking the type of it's argument. On Sat, Feb 21, 2009 at 11:10 PM, Mark Volkmann <r.mark.volkm...@gmail.com>wrote: > > On Sat, Feb 21, 2009 at 8:53 PM, André Thieme > <splendidl...@googlemail.com> wrote: > > > > On 21 Feb., 18:24, Mark Volkmann <r.mark.volkm...@gmail.com> wrote: > >> Currently the dotimes macro requires its first argument to be a vector > >> for binding a variable to the number of times the body should be > >> executed. Inside the body, that variable is bound to the values from 0 > >> to that number minus 1. How about changing this macro to also accept > >> an integer as the first argument instead of a binding vector for cases > >> where the number isn't needed in the body. > > > > I don't find this very interesting. > > There several variants of how dotimes could be, but the one that we > > currently have is the one that is used since a few decades in Lisp, > > and it is the one that makes very much sense. > > > >> For example, > >> > >> (print "Santa says") > >> (dotimes 3 (print "Ho")) > >> (.flush *out*) > > > > (print "Santa saysHoHoHo") > > > > How often do you really want to repeat the same side effect many times > > in a row? > > Why does it hurt to just say (dotimes [i 100] ...)? > > This will not reduce readability dramatically, but is a consistant > > use of dotimes. It also does not reduce productivity. > > Why make a breaking change for this? > > Why do you say it would be a breaking change? I just got the following > to work with minimal changes to the dotimes macro. > > (dotimes 3 (println "Ho")) > (dotimes [n 4] (println n)) > > So both forms work with a single macro definition. > > Here's what I did. > > 1) Wrap the body of the macro inside the following: > > (let [new-bindings (if (integer? bindings) ['n bindings] bindings)] > ... > ) > > This creates the required binding when only an integer is passed and > using the supplied value for bindings otherwise. > > 2) Change every occurrence of "bindings" in the body to "new-bindings". > > 3) Move the (defmacro dotimes ... ) to just before (defn make-array ...). > That's the first time it's used in core.clj and it will not be > after the definition of "integer?". > > Is there a reason to not make this change? > > -- > R. Mark Volkmann > Object Computing, Inc. > > > > --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
