Thank you very much Tim. I will use the eval one with "thrown?"
On Mon, Feb 25, 2013 at 6:49 AM, Tim Reinke <t...@mostcallmetim.com> wrote: > It's nice to see some input validation! > > It seems your problem, ultimately, is the testability of macros. > > You can wrap the call to the macro in an eval (this way the error is > thrown by eval, not the compiler): > > (is (thrown? AssertionError (eval '(dedefn (str "a" "b"))))) > > This can get a little ugly if you need the eval form to capture variables. > > Alternatively, you can factor the heavy lifting out of the defmacro form > and test your logic there: > > (defn defdefn* [z] > (assert (symbol? z)) > `(defn ~z [x#] x#])))) > > (defmacro dedefn [zsym] > (defdefn* (eval zsym)) > > On Saturday, February 23, 2013 11:24:26 PM UTC-8, AtKaaZ wrote: >> >> => *(defn (symbol (str "a" "b")) [x] x)* >> IllegalArgumentException First argument to defn must be a symbol >> clojure.core/defn (core.clj:277) >> >> maybe allow ~ like this: >> =>* (defn ~(symbol (str "a" "b")) [x] x)* >> IllegalArgumentException First argument to defn must be a symbol >> clojure.core/defn (core.clj:277) >> >> to act like this: >> => *(eval (backtick/template (defn ~(symbol (str "a" "b")) [x] x)))* >> #'util.funxions/ab >> >> I know you'll want to suggest something like this instead: >> => *(defmacro dedefn [zsym] >> `(defn ~(eval zsym) [x#] x#))* >> #'util.funxions/dedefn >> => *(dedefn (symbol (str "a" "b")))* >> #'util.funxions/ab >> >> which is almost good, except if you want to place extra checks on the >> input like so: >> => *(defmacro dedefn [zsym] >> (let [z (eval zsym) >> _ (assert (symbol? z)) >> ] >> `(defn ~z [x#] x#) >> ) >> )* >> #'util.funxions/dedefn >> => *(dedefn (symbol (str "a" "b")))* >> #'util.funxions/ab >> => *(dedefn (str "a" "b"))* >> AssertionError Assert failed: (symbol? z) util.funxions/dedefn >> (NO_SOURCE_FILE:3) >> >> it works but you cannot test them since they happen at compile time, ie. >> => *(clojure.test/is (thrown? AssertionError (dedefn (str "a" "b"))))* >> CompilerException java.lang.AssertionError: Assert failed: (symbol? z), >> compiling:(NO_SOURCE_PATH:1:**42) >> => *(clojure.test/is (thrown? AssertionError (throw (new >> AssertionError))))* >> #<AssertionError java.lang.AssertionError> >> => *(clojure.test/is (thrown? AssertionError 1))* >> >> FAIL in clojure.lang.PersistentList$**EmptyList@1 (NO_SOURCE_FILE:1) >> expected: (thrown? AssertionError 1) >> actual: nil >> nil >> >> I guess there's no way to get rid of that eval that's happening there >> outside of the ` in the macro, and it kinda makes sense to be that way. >> >> I have a feeling there's a workaround to be able to catch the exception >> but I haven't explored it yet... >> >> Any thoughts? >> >> -- >> Please correct me if I'm wrong or incomplete, >> even if you think I'll subconsciously hate it. >> >> -- > -- > 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. > > > -- Please correct me if I'm wrong or incomplete, even if you think I'll subconsciously hate it. -- -- 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.
