Re: Using a function to def other functions?
Ah, are you saying the binding isn't taking place at the top level because I had to call 'bar' to get the right hand side (so to speak) of the binding? And if 'bar' were a macro instead, then it would be expanded first and then nothing would have to be evaluated before binding to 'foo', and so it would be at the top level? -- 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/d/optout.
Re: Using a function to def other functions?
I don't understand -- How am I using 'def' in a non-top-level-form? I thought I was calling 'bar', getting the result which is a function, and binding that function to a name 'foo', where the binding is 'def' at the top level. Is that not what I'm doing? I'm trying to avoid the use of unnecessary macros. Is this a situation that requires macros? Eventually this might be in ClojureScript which requires macros to be handled differently... -- 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/d/optout.
Re: Using a function to def other functions?
On Aug 8, 2016 1:52 PM, wrote: > > user> (macroexpand-1 '(defn foo [x] (inc x))) > (def foo (clojure.core/fn ([x] (inc x > > If defn is just a macro, then it seems I can do this: > > user> (defn bar [] (fn ([x] (inc x > #'user/bar > > user> (def foo (bar)) > #'user/foo > > user> foo > #function[user/bar/fn--10778] > > But the result is a little different than doing it directly with defn: > > user> (defn foo [x] (inc x)) > #'user/foo > > We had #'user/bar/fn--10778 vs #'user/foo. But either way, foo is bound to something. > > Is the difference significant? It seems like it is because I tried something similar in my project and got the following: > > IllegalStateException Attempting to call unbound fn: #'p.core/default-step clojure.lang.Var$Unbound.throwArity (Var.java:43) > p.core> default-step > #function[p.core/make-step/fn--10747] > > Function default-step was def'd using make-step which returned a function and default-step is bound, so why does the repl say it is not? > > (defn make-step [some-args] > (fn ([other-args] >(some-body using-both-args > > Basically I need to define a bunch of similar functions and am trying to use another function to help define them (instead of using a macro). But it seems I'm doing something wrong... > Use the source, Luke! Spend some quality time with the source code of deftype, defrecord, ns, etc. and you will not regret it. Monkey with the ns- functions to explore namespaces, interning, etc. Make sure you grok the relation between vars and values. Once you get the hang of how Clojure does it you'll find it easy to roll your own. You will almost certainly want to use some macros, but what's wrong with that? gregg -- 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/d/optout.
Re: Using a function to def other functions?
def isn't a good example actually because it's a special form. But the same principle applies when using it as a non-top level form. On Monday, August 8, 2016 at 5:30:12 PM UTC-4, adrian...@mail.yu.edu wrote: > > defn, def, etc are what I mean by "defining macros". > > On Monday, August 8, 2016 at 5:19:04 PM UTC-4, fah...@gmail.com wrote: >> >> Oh... 'bar' and 'make-step' count as macros? My intent was that they're >> ordinary functions that return functions. Am I mistaken? Or does the issue >> you referred to apply to using defining *functions and macros *as >> non-top-level forms? >> >> (defn bar [] (fn ([x] (inc x >> >> (defn make-step [some-args] >> (fn ([other-args] >>(some-body using-both-args >> >> >> -- 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/d/optout.
Re: Using a function to def other functions?
defn, def, etc are what I mean by "defining macros". On Monday, August 8, 2016 at 5:19:04 PM UTC-4, fah...@gmail.com wrote: > > Oh... 'bar' and 'make-step' count as macros? My intent was that they're > ordinary functions that return functions. Am I mistaken? Or does the issue > you referred to apply to using defining *functions and macros *as > non-top-level forms? > > (defn bar [] (fn ([x] (inc x > > (defn make-step [some-args] > (fn ([other-args] >(some-body using-both-args > > > -- 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/d/optout.
Re: Using a function to def other functions?
Oh... 'bar' and 'make-step' count as macros? My intent was that they're ordinary functions that return functions. Am I mistaken? Or does the issue you referred to apply to using defining *functions and macros *as non-top-level forms? (defn bar [] (fn ([x] (inc x (defn make-step [some-args] (fn ([other-args] (some-body using-both-args -- 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/d/optout.
Re: Using a function to def other functions?
Using defining macros as non top-level forms may not be forbidden by the language but its use is generally discouraged. See http://clhs.lisp.se/Issues/iss104_w.htm for a discussion about this issue in Common Lisp for some background context. In short, compile time effects may not be captured whenever you use defining macros as non top-level forms. I think you're seeing something like this manifest here. In this case, since you referenced a var which was not installed when the compiler reaches the calling code, the compiler will throw this error message. I would suggest rethinking this because the solution is ugly, but you should use something like clojure.core/resolve or clojure.core/ns-resolve to resolve the var dynamically and then funcall it. On Monday, August 8, 2016 at 2:52:37 PM UTC-4, fah...@gmail.com wrote: > > user> (macroexpand-1 '(defn foo [x] (inc x))) > (def foo (clojure.core/fn ([x] (inc x > > If defn is just a macro, then it seems I can do this: > > user> (defn bar [] (fn ([x] (inc x > #'user/bar > > user> (def foo (bar)) > #'user/foo > > user> foo > #function[user/bar/fn--10778] > > But the result is a little different than doing it directly with defn: > > user> (defn foo [x] (inc x)) > #'user/foo > > We had #'user/*bar/fn--10778* vs #'user/foo. But either way, foo is bound > to something. > > Is the difference significant? It seems like it is because I tried > something similar in my project and got the following: > > IllegalStateException Attempting to call unbound fn: #'p.core/default-step > clojure.lang.Var$Unbound.throwArity (Var.java:43) > p.core> default-step > #function[p.core/make-step/fn--10747] > > Function default-step was def'd using make-step which returned a function > and default-step is bound, so why does the repl say it is not? > > (defn make-step [some-args] > (fn ([other-args] >(some-body using-both-args > > Basically I need to define a bunch of similar functions and am trying to > use another function to help define them (instead of using a macro). But it > seems I'm doing something wrong... > -- 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/d/optout.
