Re: reader conditional not handling defmacro?
Alex, On the Dev list, you mentioned you had discussed this several times with Rich and others, but were unable to reach concensus. May I ask what the hangup is (i.e., what reservations / objections were expressed) and what other options came out of those discussions? Nathan Davis On Friday, May 27, 2016 at 7:39:15 AM UTC-5, Alex Miller wrote: > > That is one option and is in the ballpark of > http://dev.clojure.org/jira/browse/CLJ-1750. > > On Thursday, May 26, 2016 at 11:47:09 PM UTC-5, Nathan Davis wrote: >> >> I can't reply to the thread on the Dev list, but here's my take. >> >> Unless I'm missing something, it seems to me that most these issues could >> be resolved by having a dynamic var that gets set during macro expansion >> according to the target platform. For instance, *compiler-target* is >> set to :clj or :cljs, depending on whether we're compiler for the JVM or >> Javascript. If we want to be a little more sophisticated, >> *compiler-target* could be a set whose members are the same keywords >> that were "active" at read-time. That would have the additional >> convenience that *compiler-target* would act as a predicate, indicating >> whether a particular "feature" is available for the target platform. >> >> Then if a macro needs to be expanded in a certain way for certain >> platforms, it can just consult *compiler-target*. >> >> Anyway, that's my 2-cents. >> >> Nathan Davis >> >> >> On Sunday, May 22, 2016 at 5:57:14 PM UTC-5, Herwig Hochleitner wrote: >>> >>> This thread just came up, while I was in the process of composing a mail >>> on this topic to clojure-dev: >>> https://groups.google.com/d/msg/clojure-dev/f6ULUVokXrU/3uue5okSAgAJ >>> >>> 2016-05-20 23:22 GMT+02:00 Dan Burton : >>> What about something like (def obj #?(:clj Object :cljs js/Object)) >>> >>> Unfortunately, doesn't work for cases, where you need to generate >>> different syntax, eg `(try .. (catch Throwable e ...))` vs `(try ... (catch >>> :default e ...))`. >>> >>> -- 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: reader conditional not handling defmacro?
That is one option and is in the ballpark of http://dev.clojure.org/jira/browse/CLJ-1750. On Thursday, May 26, 2016 at 11:47:09 PM UTC-5, Nathan Davis wrote: > > I can't reply to the thread on the Dev list, but here's my take. > > Unless I'm missing something, it seems to me that most these issues could > be resolved by having a dynamic var that gets set during macro expansion > according to the target platform. For instance, *compiler-target* is set > to :clj or :cljs, depending on whether we're compiler for the JVM or > Javascript. If we want to be a little more sophisticated, > *compiler-target* could be a set whose members are the same keywords that > were "active" at read-time. That would have the additional convenience > that *compiler-target* would act as a predicate, indicating whether a > particular "feature" is available for the target platform. > > Then if a macro needs to be expanded in a certain way for certain > platforms, it can just consult *compiler-target*. > > Anyway, that's my 2-cents. > > Nathan Davis > > > On Sunday, May 22, 2016 at 5:57:14 PM UTC-5, Herwig Hochleitner wrote: >> >> This thread just came up, while I was in the process of composing a mail >> on this topic to clojure-dev: >> https://groups.google.com/d/msg/clojure-dev/f6ULUVokXrU/3uue5okSAgAJ >> >> 2016-05-20 23:22 GMT+02:00 Dan Burton : >> >>> What about something like >>> >>> (def obj #?(:clj Object :cljs js/Object)) >>> >> >> Unfortunately, doesn't work for cases, where you need to generate >> different syntax, eg `(try .. (catch Throwable e ...))` vs `(try ... (catch >> :default e ...))`. >> >> -- 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: reader conditional not handling defmacro?
I can't reply to the thread on the Dev list, but here's my take. Unless I'm missing something, it seems to me that most these issues could be resolved by having a dynamic var that gets set during macro expansion according to the target platform. For instance, *compiler-target* is set to :clj or :cljs, depending on whether we're compiler for the JVM or Javascript. If we want to be a little more sophisticated, *compiler-target* could be a set whose members are the same keywords that were "active" at read-time. That would have the additional convenience that *compiler-target* would act as a predicate, indicating whether a particular "feature" is available for the target platform. Then if a macro needs to be expanded in a certain way for certain platforms, it can just consult *compiler-target*. Anyway, that's my 2-cents. Nathan Davis On Sunday, May 22, 2016 at 5:57:14 PM UTC-5, Herwig Hochleitner wrote: > > This thread just came up, while I was in the process of composing a mail > on this topic to clojure-dev: > https://groups.google.com/d/msg/clojure-dev/f6ULUVokXrU/3uue5okSAgAJ > > 2016-05-20 23:22 GMT+02:00 Dan Burton > > : > >> What about something like >> >> (def obj #?(:clj Object :cljs js/Object)) >> > > Unfortunately, doesn't work for cases, where you need to generate > different syntax, eg `(try .. (catch Throwable e ...))` vs `(try ... (catch > :default e ...))`. > > -- 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: reader conditional not handling defmacro?
This thread just came up, while I was in the process of composing a mail on this topic to clojure-dev: https://groups.google.com/d/msg/clojure-dev/f6ULUVokXrU/3uue5okSAgAJ 2016-05-20 23:22 GMT+02:00 Dan Burton : > What about something like > > (def obj #?(:clj Object :cljs js/Object)) > Unfortunately, doesn't work for cases, where you need to generate different syntax, eg `(try .. (catch Throwable e ...))` vs `(try ... (catch :default e ...))`. -- 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: reader conditional not handling defmacro?
What about something like ;; obj.cljc (ns obj) (def obj #?(:clj Object :cljs js/Object)) (defmacro get-obj [] `obj) ;; obj-test.cljc (ns obj-test (:require [obj :refer-macros [get-obj]])) (def gotten-obj (obj/get-obj)) Load obj-test in clj, and obj-test/gotten-obj is Object. Load it in cljs, and gotten-obj is js/Object. Thus, you can write cljc macros that symbolically refer to obj/obj and turn out as the correct thing. This is because the macro doesn't refer to the *value* of obj, just to the symbol, which isn't evaluated until runtime. -- Dan Burton On Fri, May 20, 2016 at 11:22 AM, hiskennyness wrote: > Thanks, Sean. (My follow-up fix request went out just as your fix came in.) > > -kt > > > On Friday, May 20, 2016 at 2:16:47 PM UTC-4, hiskennyness wrote: >> >> >> >> On Friday, May 20, 2016 at 1:34:43 PM UTC-4, hiskennyness wrote: >>> >>> My next problem with .cljc (which is going very very well overall!) has >>> to do with macros. >>> snip >>> >>> ps. I will try the old trick of having a helper defn with-defobserver >>> and with-whatever to see if this is purely a macro interaction. >>> >> >> Not surprisingly, that worked on the second (unposted) example which >> could be divided/conquered into a helper defn (tho my CL is getting rusty, >> the old trick is call-with-whatever). >> >> Unfortunately the other case (the one shown) really is a conditional >> code-rewriting that has to happen at macroexpansion time, so a fix is still >> needed. >> >> >> -- > 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. > -- 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: reader conditional not handling defmacro?
Thanks, Sean. (My follow-up fix request went out just as your fix came in.) -kt On Friday, May 20, 2016 at 2:16:47 PM UTC-4, hiskennyness wrote: > > > > On Friday, May 20, 2016 at 1:34:43 PM UTC-4, hiskennyness wrote: >> >> My next problem with .cljc (which is going very very well overall!) has >> to do with macros. >> snip >> >> ps. I will try the old trick of having a helper defn with-defobserver and >> with-whatever to see if this is purely a macro interaction. >> > > Not surprisingly, that worked on the second (unposted) example which could > be divided/conquered into a helper defn (tho my CL is getting rusty, the > old trick is call-with-whatever). > > Unfortunately the other case (the one shown) really is a conditional > code-rewriting that has to happen at macroexpansion time, so a fix is still > needed. > > > -- 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: reader conditional not handling defmacro?
On Friday, May 20, 2016 at 1:34:43 PM UTC-4, hiskennyness wrote: > > My next problem with .cljc (which is going very very well overall!) has to > do with macros. > snip > > ps. I will try the old trick of having a helper defn with-defobserver and > with-whatever to see if this is purely a macro interaction. > Not surprisingly, that worked on the second (unposted) example which could be divided/conquered into a helper defn (tho my CL is getting rusty, the old trick is call-with-whatever). Unfortunately the other case (the one shown) really is a conditional code-rewriting that has to happen at macroexpansion time, so a fix is still needed. -- 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: reader conditional not handling defmacro?
This is because the macros are expanded by Clojure so inside a macro, it always looks like :clj. Take a look at how Expectations gets around this: https://github.com/jaycfields/expectations/blob/master/src/cljc/expectations/platform.cljc#L9-L21 I’d love to hear if there’s an “official” recommended way to deal with reader conditionals in macros used from ClojureScript? Sean Corfield -- (904) 302-SEAN An Architect's View -- http://corfield.org/ "If you're not annoying somebody, you're not really alive." -- Margaret Atwood On 5/20/16, 10:34 AM, "hiskennyness" wrote: My next problem with .cljc (which is going very very well overall!) has to do with macros. Should I mention that I am building under Figwheel? This toolchain stuff has this old Lisper's head spinning. Without a conditional, code using this macro compiles fine (the key bit being where I offer devs a little syntactic sugar in coding up defobserver so they can omit the dispatching types js/object (which I myself rarely specify): (defmacro defobserver [slot types params & body] (assert (keyword? slot) "defobserver> slot should be a keyword.") (let [ftypes (concat types (take-last (- 3 (count types)) '(::tiltontec.modeller.cell-types/model js/object js/object))) fparams (concat params (take-last (- 4 (count params)) '(me new-value old-value c)))] `(defmethod tiltontec.modeller.observer/observe [~slot ~@ftypes][~'slot ~@fparams] ~@body))) But on clj those need to be Object. So I tried this (after wrapping the above in #?(:cljs ...): #_(:clj (defmacro defobserver [slot types params & body] (assert (keyword? slot) "defobserver> slot should be a keyword.") (let [ftypes (concat types (take-last (- 3 (count types)) '(::tiltontec.modeller.cell-types/model Object Object))) fparams (concat params (take-last (- 4 (count params)) '(me new-value old-value c)))] `(defmethod tiltontec.modeller.observer/observe [~slot ~@ftypes][~'slot ~@fparams] ~@body And in fact, that was a brave attempt to salvage my original attempt, which conditionalized just the types: #?(:clj Object :cljs js/object) I repeated that twice, but just realized this would have been a good spot for the splicing variant. Anyway, no matter what I do I get a warning compiling to cljs that Object is unknown, and indeed a macroexpand-1 of '(defobserver :fu [nil][_ _ _ _] 42) shows Object where I should be seeing js/object. I am also getting the same problem with an unrelated macro in which I am trying to conditionalize between dosync and do. Interestingly, I just noticed the same macro conditionally chooses between Exception. and js/Error. and I am not seeing warnings there! Is this another known issue? ps. I will try the old trick of having a helper defn with-defobserver and with-whatever to see if this is purely a macro interaction. -- 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.
reader conditional not handling defmacro?
My next problem with .cljc (which is going very very well overall!) has to do with macros. Should I mention that I am building under Figwheel? This toolchain stuff has this old Lisper's head spinning. Without a conditional, code using this macro compiles fine (the key bit being where I offer devs a little syntactic sugar in coding up defobserver so they can omit the dispatching types js/object (which I myself rarely specify): (defmacro defobserver [slot types params & body] (assert (keyword? slot) "defobserver> slot should be a keyword.") (let [ftypes (concat types (take-last (- 3 (count types)) '(::tiltontec.modeller.cell-types/model js/object js/object))) fparams (concat params (take-last (- 4 (count params)) '(me new-value old-value c)))] `(defmethod tiltontec.modeller.observer/observe [~slot ~@ftypes][~'slot ~@fparams] ~@body))) But on clj those need to be Object. So I tried this (after wrapping the above in #?(:cljs ...): #_(:clj (defmacro defobserver [slot types params & body] (assert (keyword? slot) "defobserver> slot should be a keyword.") (let [ftypes (concat types (take-last (- 3 (count types)) '(::tiltontec.modeller.cell-types/model Object Object))) fparams (concat params (take-last (- 4 (count params)) '(me new-value old-value c)))] `(defmethod tiltontec.modeller.observer/observe [~slot ~@ftypes][~'slot ~@fparams] ~@body And in fact, that was a brave attempt to salvage my original attempt, which conditionalized just the types: #?(:clj Object :cljs js/object) I repeated that twice, but just realized this would have been a good spot for the splicing variant. Anyway, no matter what I do I get a warning compiling to cljs that Object is unknown, and indeed a macroexpand-1 of '(defobserver :fu [nil][_ _ _ _] 42) shows Object where I should be seeing js/object. I am also getting the same problem with an unrelated macro in which I am trying to conditionalize between dosync and do. Interestingly, I just noticed the same macro conditionally chooses between Exception. and js/Error. and I am not seeing warnings there! Is this another known issue? ps. I will try the old trick of having a helper defn with-defobserver and with-whatever to see if this is purely a macro interaction. -- 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.
