> Welcome to a world of values, not containers (the blue pieces can only fit in the blue > container, the red ones .... you get the picture) or as Rich says places.
I always thought that by places he means mutable identifiers; languages like Haskell have a lot of luck with type-checking immutable *values*. I don't see how appreciation for values over places leads to lack of type-checking. On Wednesday, February 6, 2013 4:50:54 AM UTC+4, Luc wrote: > > You are not defining a type here. A type hint is just that... a hint so > the compiler > can optimize the code it generates to call the readLine method on this > specific > object class. > > As an example, if io/reader returned an object of a different class at > runtime > than BufferedReader, it would not fail even if the hint says "expect an > object of this class". > > The generated code testing that the object is not of the hinted class > would > resort to reflection on the object class to find if the readLine method > exists. > If not you will get the usual runtime error saying that the method does > not exists. > > The Clojure compiler has no type checking equivalent to Java, C, ... > You can define stuff that is not even bound to a value, it would be hard > to type check on > these at compile time, no ? > > Welcome to a world of values, not containers (the blue pieces can only fit > in the blue > container, the red ones .... you get the picture) or as Rich says places. > > Luc P. > > > > That's funny, I did exactly the same thing and wrote BufferedReader for > > both. DOH! > > > > Although I have no idea how the internals of type hinting is, I do think > > it's peculiar that there doesn't seem to be type error checking, even > > though we are explicitly "defining" the type. I would feel like it > should > > error, instead of falling back on reflection. > > > > Kanwei > > > > On Monday, February 4, 2013 12:36:51 PM UTC-5, AtKaaZ wrote: > > > > > > in other words: > > > this: > > > > > > (let [in (clojure.java.io/reader src) > > > out (clojure.java.io/writer dest) > > > > > > > > > becomes this: > > > (let [^java.io.BufferedReader in (clojure.java.io/reader src) > > > ^java.io.BufferedWriter out (clojure.java.io/writer dest) > > > > > > > > > and it works for me too. (but I wasted some time by having > BufferedReader > > > in both places) > > > > > > > > > On Mon, Feb 4, 2013 at 6:26 PM, Andy Fingerhut > > > <andy.fi...@gmail.com<javascript:> > > > > > wrote: > > > > > >> I don't have CCW Eclipse installed to test, but by saving that file > on my > > >> Mac (should also work on Linux) in a subdirectory "obj", and editing > it to > > >> add the ^java.io.BufferedReader in and ^java.io.BufferedWriter out > type > > >> hints as suggested by Luc P. earlier in this thread, I was able to > > >> eliminate the reflection warnings: > > >> > > >> % mkdir obj > > >> % cp <gist_file> obj/solutions.clj > > >> > > >> # Original file without the type hints gives reflection warnings as > > >> expected > > >> > > >> % java -Dclojure.compile.path=./obj -cp clojure-1.4.0.jar:./obj > > >> clojure.lang.Compile solution > > >> Compiling solution to ./obj > > >> Reflection warning, solution.clj:38 - reference to field readLine > can't > > >> be resolved. > > >> Reflection warning, solution.clj:45 - reference to field readLine > can't > > >> be resolved. > > >> Reflection warning, solution.clj:63 - reference to field newLine > can't be > > >> resolved. > > >> Reflection warning, solution.clj:54 - reference to field newLine > can't be > > >> resolved. > > >> > > >> # Now I hand-edit obj/solutions.clj to add the type hints, and > recompile. > > >> No reflection warnings. > > >> % java -Dclojure.compile.path=./obj -cp clojure-1.4.0.jar:./obj > > >> clojure.lang.Compile solution > > >> Compiling solution to ./obj > > >> % > > >> > > >> Perhaps you should try verifying that you added the type hints > correctly, > > >> saved the source file, recompiled the one you wanted to in CCW > Eclipse, etc. > > >> > > >> Andy > > >> > > >> > > >> On Feb 4, 2013, at 9:10 AM, Kanwei Li wrote: > > >> > > >> Hey Andy, > > >> > > >> Thanks for offering to help. Here's a gist: > > >> https://gist.github.com/4696105 > > >> > > >> As you can see at the bottom, I want the main method to read/write to > > >> STDIN/STDOUT, but for testing, I want to read from files instead. > > >> > > >> This is what I get in both CCW Eclipse and nrepl: > > >> > > >> Reflection warning, NO_SOURCE_PATH:4 - reference to field readLine > can't > > >> be resolved. > > >> > > >> Reflection warning, NO_SOURCE_PATH:11 - reference to field readLine > can't > > >> be resolved. > > >> > > >> Reflection warning, NO_SOURCE_PATH:29 - reference to field newLine > can't > > >> be resolved. > > >> > > >> Reflection warning, NO_SOURCE_PATH:20 - reference to field newLine > can't > > >> be resolved. > > >> Thanks! > > >> > > >> On Sunday, February 3, 2013 4:38:38 PM UTC-5, Andy Fingerhut wrote: > > >>> > > >>> Can you post a larger chunk of code for us to examine, perhaps on > github > > >>> or as a gist if it is over 30 lines of code or so? Many of us have > had > > >>> good success with eliminating reflection using type hints, so it > should be > > >>> possible to make it work. > > >>> > > >>> Andy > > >>> > > >>> On Feb 3, 2013, at 12:50 PM, Kanwei Li wrote: > > >>> > > >>> Unfortunately it doesn't work. > > >>> > > >>> Reflection warning, NO_SOURCE_PATH:20 - call to write can't be > resolved. > > >>> > > >>> Reflection warning, NO_SOURCE_PATH:21 - reference to field newLine > can't > > >>> be resolved. > > >>> > > >>> On Sunday, February 3, 2013 2:35:23 PM UTC-5, Luc wrote: > > >>>> > > >>>> Why not add type hints like this ? > > >>>> > > >>>> (let [^java.io.BufferedReader in .... > > >>>> ^java.io.BufferedWriter out ...] > > >>>> .. > > >>>> > > >>>> Luc P. > > >>>> > > >>>> > Hey guys, > > >>>> > > > >>>> > I'm trying to read a lot of data, sometimes from *in* and > sometimes > > >>>> from a > > >>>> > file. I extensively use the native .write and .read java methods. > > >>>> > > > >>>> > According to the clojure doc for reader, it says that "Default > > >>>> > implementations always return a BufferedReader". However, when I > > >>>> write, > > >>>> > > > >>>> > (*defn* solve [src dest] > > >>>> > > > >>>> > (*let* [in (clojure.java.io/reader src) > > >>>> > > > >>>> > out (clojure.java.io/writer dest) > > >>>> > > > >>>> > I get a bunch of reflection warnings on .read and .write, and > most of > > >>>> the > > >>>> > running time is spent on reflection. AFAIK you can't type hint a > > >>>> (let) > > >>>> > construct, so what should I do here? > > >>>> > > > >>>> > Thanks! > > >>> > > >>> > > >> -- > > >> -- > > >> 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 > > >> 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. > > >> > > >> > > >> > > > > > > > > > > > > -- > > > 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 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. > > > > > > > -- > Softaddicts<lprefo...@softaddicts.ca <javascript:>> sent by ibisMail from > my ipad! > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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