Re: type function returning a NullPointerException
What's the stack trace when you get an NPE? (pst *e) Are you shadowing a core function with your own `count` or something like that? On Friday, February 15, 2019 at 8:27:55 AM UTC-6, KJO wrote: > > Hi- > > This one has me stumped. The following code snippet throws a > NullPointerException and I just can't understand how it could. > > (if (set? t-val) > (println t-val (type t-val))) > > It seems that if it's a set, it should have a set type. > > If I change the code to > > (if (set? t-val) > (println t-val (count t-val))) > > It throws a ClassCastException > with java.math.BigDecimal cannot be cast to clojure.lang.IFn > > The println is only there for debugging. I was seeing the count function > throwing an exception further down in the code, and I couldn't understand > why. Any ideas? > > t-val is defined in a let, but if I take it out and use the original > value, the result is the same. I'm afraid I can't reproduce the error in > the REPL using any of the values I captured. The only other thing I can > offer is that it's being used in a reducing function over a lazy sequence. > > I'm stumped. > > Thanks > > -- 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: type function returning a NullPointerException
Damn! That shadowing thing has tripped me up a bunch of times. I'm sheepish. Thanks for the reply. And the type thing is just more of the same (more sheepish) - events do conspire against us. I'd been trying to track it down for quite a while. Appreciate the help. Best On Friday, February 15, 2019 at 9:32:02 AM UTC-5, Alex Miller wrote: > > What's the stack trace when you get an NPE? (pst *e) > > Are you shadowing a core function with your own `count` or something like > that? > > On Friday, February 15, 2019 at 8:27:55 AM UTC-6, KJO wrote: >> >> Hi- >> >> This one has me stumped. The following code snippet throws a >> NullPointerException and I just can't understand how it could. >> >> (if (set? t-val) >> (println t-val (type t-val))) >> >> It seems that if it's a set, it should have a set type. >> >> If I change the code to >> >> (if (set? t-val) >> (println t-val (count t-val))) >> >> It throws a ClassCastException >> with java.math.BigDecimal cannot be cast to clojure.lang.IFn >> >> The println is only there for debugging. I was seeing the count function >> throwing an exception further down in the code, and I couldn't understand >> why. Any ideas? >> >> t-val is defined in a let, but if I take it out and use the original >> value, the result is the same. I'm afraid I can't reproduce the error in >> the REPL using any of the values I captured. The only other thing I can >> offer is that it's being used in a reducing function over a lazy sequence. >> >> I'm stumped. >> >> Thanks >> >> -- 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.
type function returning a NullPointerException
Hi- This one has me stumped. The following code snippet throws a NullPointerException and I just can't understand how it could. (if (set? t-val) (println t-val (type t-val))) It seems that if it's a set, it should have a set type. If I change the code to (if (set? t-val) (println t-val (count t-val))) It throws a ClassCastException with java.math.BigDecimal cannot be cast to clojure.lang.IFn The println is only there for debugging. I was seeing the count function throwing an exception further down in the code, and I couldn't understand why. Any ideas? t-val is defined in a let, but if I take it out and use the original value, the result is the same. I'm afraid I can't reproduce the error in the REPL using any of the values I captured. The only other thing I can offer is that it's being used in a reducing function over a lazy sequence. I'm stumped. Thanks -- 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: Got NullpointerException when using loop/recur/let together
Also, have another look at '(ret (- time-now start-time)) It will yield a list containing the symbol 'ret and a nested list containing the symbol '- etc etc etc. I think what you expected was a vector of two numbers. -- 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: Got NullpointerException when using loop/recur/let together
you wrap a call to Thread/sleep in parens, in clojure this means you want to call it, Thread/sleep returns nil and calling nil gives a NullpointerException Parens are not for grouping or sequencing things in clojure, and you don't need them here - fn has an implicit do block already, in other contexts where there isn't a do block implicitly, you can use do to sequence expressions On Tue, Oct 24, 2017 at 5:26 PM yihao yang <yangyihao1...@gmail.com> wrote: > Hi, all > > I want to do sth. like query until timeout. So I write a function below. > (defn wait-ls-ready > [] > (let [pair-fn (fn [] ( > (Thread/sleep 1000) > (let [ret (try > (c/exec :ls) > 0 > (catch RuntimeException e -1) >), >time-now (quot (System/currentTimeMillis) > 1000)] >'(ret (- time-now start-time)) > ) >))] > (loop [start-time (quot (System/currentTimeMillis) 1000) >time-out 10] > (let [[ret time-delta] (pair-fn)] > (info node "Waiting gsql works...") > (if (= 0 ret) 0 > (if (> time-delta time-out) > (throw (RuntimeException. > (str "'ls' not working in " time-out "seconds."))) > (recur start-time time-out > ) > ) > ) > > But it returns a NullpointerException after 1 seconds. Could anyone help > me out? > > Thanks, > Yihao > > -- > 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.
Got NullpointerException when using loop/recur/let together
Hi, all I want to do sth. like query until timeout. So I write a function below. (defn wait-ls-ready [] (let [pair-fn (fn [] ( (Thread/sleep 1000) (let [ret (try (c/exec :ls) 0 (catch RuntimeException e -1) ), time-now (quot (System/currentTimeMillis) 1000)] '(ret (- time-now start-time)) ) ))] (loop [start-time (quot (System/currentTimeMillis) 1000) time-out 10] (let [[ret time-delta] (pair-fn)] (info node "Waiting gsql works...") (if (= 0 ret) 0 (if (> time-delta time-out) (throw (RuntimeException. (str "'ls' not working in " time-out "seconds."))) (recur start-time time-out)))) ) ) ) But it returns a NullpointerException after 1 seconds. Could anyone help me out? Thanks, Yihao -- 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.
NullPointerException on ManagementFactory/getThreadMXBean ???
I've never had this problem before, but now I'm getting this:
in resource-usage there was this exception: #
at startup, for this function:
(defn- resource-usage []
(let [my-pool (at/mk-pool)]
(at/every 6
(fn []
(try
(timbre/log :trace "Resource usage: "
(monitoring/show-stats-regarding-resources-used-by-this-app))
(doseq [x (monitoring/thread-top)]
(timbre/log :trace x))
(catch Exception e (println "in resource-usage there was
this exception: " e
my-pool)))
This line:
(timbre/log :trace "Resource usage: "
(monitoring/show-stats-regarding-resources-used-by-this-app))
Correctly gives me:
Resource usage: Memory in use (percentage/used/max-heap): ("9%" "43M"
"444M")
So the problem comes here:
(doseq [x (monitoring/thread-top)]
(timbre/log :trace x))
Which relies on java.lang.management.ManagementFactory
(defn thread-top
"Return a seq of threads sorted by their total userland CPU usage."
[]
(let [mgr (ManagementFactory/getThreadMXBean)
cpu-times (map (fn [t]
[(.getThreadCpuTime mgr (.getId t)) t])
(threads))]
(map
(fn [[cpu t]] [cpu (.getName t) (.getId t) t])
(reverse (sort-by first cpu-times)
With some code borrowed from here:
http://lifeisagraph.com/2011/04/24/debugging-clojure.html
Does anyone see a place where a NullPointerException might get started?
I assume this must be some circumstance unique to startup. I don't think
this problem repeats.
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Re: NullPointerException on ManagementFactory/getThreadMXBean ???
This error is also intermittent. It doesn't happen every time I start the
app. I would guess this is some kind of timing issue, but I can't think
where the issue of timing comes up.
On Monday, January 25, 2016 at 4:04:50 PM UTC-5, piast...@gmail.com wrote:
>
> I've never had this problem before, but now I'm getting this:
>
> in resource-usage there was this exception: # java.lang.NullPointerException>
>
> at startup, for this function:
>
> (defn- resource-usage []
> (let [my-pool (at/mk-pool)]
> (at/every 6
> (fn []
> (try
> (timbre/log :trace "Resource usage: "
>
> (monitoring/show-stats-regarding-resources-used-by-this-app))
> (doseq [x (monitoring/thread-top)]
> (timbre/log :trace x))
> (catch Exception e (println "in resource-usage there was
> this exception: " e
> my-pool)))
>
>
> This line:
>
> (timbre/log :trace "Resource usage: "
>
> (monitoring/show-stats-regarding-resources-used-by-this-app))
>
> Correctly gives me:
>
> Resource usage: Memory in use (percentage/used/max-heap): ("9%" "43M"
> "444M")
>
> So the problem comes here:
>
> (doseq [x (monitoring/thread-top)]
> (timbre/log :trace x))
>
> Which relies on java.lang.management.ManagementFactory
>
> (defn thread-top
> "Return a seq of threads sorted by their total userland CPU usage."
> []
> (let [mgr (ManagementFactory/getThreadMXBean)
> cpu-times (map (fn [t]
> [(.getThreadCpuTime mgr (.getId t)) t])
> (threads))]
> (map
> (fn [[cpu t]] [cpu (.getName t) (.getId t) t])
> (reverse (sort-by first cpu-times)
>
>
> With some code borrowed from here:
>
> http://lifeisagraph.com/2011/04/24/debugging-clojure.html
>
> Does anyone see a place where a NullPointerException might get started?
>
> I assume this must be some circumstance unique to startup. I don't think
> this problem repeats.
>
>
>
>
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Re: NullPointerException when creating protocol in macro
Thanks everyone for your answers. I must say I'm quite mystified as to why Stuart's version works. I ended up defining a function that has the same signature as the protocol, and whose first argument wraps a function that contains the appropriate code. Vincent On Wednesday, 5 June 2013 23:57:16 UTC+2, Stuart Sierra wrote: Hi Vincent, `defprotocol` is a top-level form, not really meant to be mixed with value-returning expressions like `fn`. Protocols are always global because of how they compile into Java interfaces. Here's one way to make it work, by defining a symbol instead of returning a function: (defmacro create-protocol [protocol symbol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (defn ~symbol [] (reify ~protocol-name ~implementation) (create-protocol [P (method [this])] constructor (method [this] (println method))) (method (constructor)) -S On Wednesday, June 5, 2013 9:16:05 AM UTC-4, Vincent wrote: I’m trying to write a macro that defines a protocol and a function that, when called, returns an implementation of that protocol. I’ve reduced the code to the following example: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (fn [] (reify ~protocol-name ~implementation) (let [f (create-protocol [P (method [this])] (method [this] (println method)))] (method (f))) The original code is more complicated, where the function will read a value from a file and, depending on that value, return the appropriate implementation of the protocol. When I run Clojure 1.5.1 on that code I get the following exception: Exception in thread main java.lang.NullPointerException, compiling:(protocol.clj:7:9) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6567) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5973) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.eval(Compiler.java:6616) at clojure.lang.Compiler.load(Compiler.java:7064) at clojure.lang.Compiler.loadFile(Compiler.java:7020) at clojure.main$load_script.invoke(main.clj:294) at clojure.main$script_opt.invoke(main.clj:356) at clojure.main$main.doInvoke(main.clj:440) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) Caused by: java.lang.NullPointerException at clojure.lang.Compiler.resolveIn(Compiler.java:6840) at clojure.lang.Compiler.resolve(Compiler.java:6818) at clojure.lang.Compiler$NewInstanceExpr.build(Compiler.java:7427) at clojure.lang.Compiler$NewInstanceExpr$ReifyParser.parse(Compiler.java:7377) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) ... 38 more From what I understood by tracing through the compiler it seems that the P var is created at macro expansion time but bound at execution time only. When expanding the ‘reify’ macro, P is still unbound, which yields a nil interface, which triggers the NPE. I could solve the problem by redefining the macro in the following way: (defmacro create-protocol [protocol
NullPointerException when creating protocol in macro
I’m trying to write a macro that defines a protocol and a function that, when called, returns an implementation of that protocol. I’ve reduced the code to the following example: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (fn [] (reify ~protocol-name ~implementation) (let [f (create-protocol [P (method [this])] (method [this] (println method)))] (method (f))) The original code is more complicated, where the function will read a value from a file and, depending on that value, return the appropriate implementation of the protocol. When I run Clojure 1.5.1 on that code I get the following exception: Exception in thread main java.lang.NullPointerException, compiling:(protocol.clj:7:9) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6567) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5973) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.eval(Compiler.java:6616) at clojure.lang.Compiler.load(Compiler.java:7064) at clojure.lang.Compiler.loadFile(Compiler.java:7020) at clojure.main$load_script.invoke(main.clj:294) at clojure.main$script_opt.invoke(main.clj:356) at clojure.main$main.doInvoke(main.clj:440) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) Caused by: java.lang.NullPointerException at clojure.lang.Compiler.resolveIn(Compiler.java:6840) at clojure.lang.Compiler.resolve(Compiler.java:6818) at clojure.lang.Compiler$NewInstanceExpr.build(Compiler.java:7427) at clojure.lang.Compiler$NewInstanceExpr$ReifyParser.parse(Compiler.java:7377) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) ... 38 more From what I understood by tracing through the compiler it seems that the P var is created at macro expansion time but bound at execution time only. When expanding the ‘reify’ macro, P is still unbound, which yields a nil interface, which triggers the NPE. I could solve the problem by redefining the macro in the following way: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] (eval `(defprotocol ~protocol-name ~signature)) `(fn [] (reify ~protocol-name ~implementation Using eval doesn’t feel right though. I guess I could modify my code to avoid using protocols, but it seemed to me to be the most natural way of achieving what I wanted. I was just wondering if anybody had any opinion or suggestion about that. Am I going off track? Is there a more idiomatic way of doing things that I missed? Thanks, Vincent -- -- 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
Re: NullPointerException when creating protocol in macro
Hi Vincent, `defprotocol` is a top-level form, not really meant to be mixed with value-returning expressions like `fn`. Protocols are always global because of how they compile into Java interfaces. Here's one way to make it work, by defining a symbol instead of returning a function: (defmacro create-protocol [protocol symbol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (defn ~symbol [] (reify ~protocol-name ~implementation) (create-protocol [P (method [this])] constructor (method [this] (println method))) (method (constructor)) -S On Wednesday, June 5, 2013 9:16:05 AM UTC-4, Vincent wrote: I’m trying to write a macro that defines a protocol and a function that, when called, returns an implementation of that protocol. I’ve reduced the code to the following example: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (fn [] (reify ~protocol-name ~implementation) (let [f (create-protocol [P (method [this])] (method [this] (println method)))] (method (f))) The original code is more complicated, where the function will read a value from a file and, depending on that value, return the appropriate implementation of the protocol. When I run Clojure 1.5.1 on that code I get the following exception: Exception in thread main java.lang.NullPointerException, compiling:(protocol.clj:7:9) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6567) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5973) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.analyze(Compiler.java:6322) at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5708) at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5139) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3751) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(Compiler.java:6361) at clojure.lang.Compiler.eval(Compiler.java:6616) at clojure.lang.Compiler.load(Compiler.java:7064) at clojure.lang.Compiler.loadFile(Compiler.java:7020) at clojure.main$load_script.invoke(main.clj:294) at clojure.main$script_opt.invoke(main.clj:356) at clojure.main$main.doInvoke(main.clj:440) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) Caused by: java.lang.NullPointerException at clojure.lang.Compiler.resolveIn(Compiler.java:6840) at clojure.lang.Compiler.resolve(Compiler.java:6818) at clojure.lang.Compiler$NewInstanceExpr.build(Compiler.java:7427) at clojure.lang.Compiler$NewInstanceExpr$ReifyParser.parse(Compiler.java:7377) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6560) ... 38 more From what I understood by tracing through the compiler it seems that the P var is created at macro expansion time but bound at execution time only. When expanding the ‘reify’ macro, P is still unbound, which yields a nil interface, which triggers the NPE. I could solve the problem by redefining the macro in the following way: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] (eval `(defprotocol ~protocol-name ~signature)) `(fn [] (reify ~protocol-name ~implementation Using eval doesn’t feel right though. I guess I could modify my code to avoid using protocols, but it seemed to me to be the most natural way of achieving what I wanted. I
Re: NullPointerException when creating protocol in macro
*`defprotocol` is a top-level form...* This is interesting, and it's something I've wondered about. As far as I can tell, there's really no distinction between top-level forms and other forms, for example this is legal and works: (defn define-my-functions [] (defn test-1 [] 1) (defn test-2 [] 2)) = #=(var plugin.performance.project/define-my-functions) test-1 = Unbound: #'plugin.performance.project/test-1 test-2 = Unbound: #'plugin.performance.project/test-2 (define-my-functions) = #=(var plugin.performance.project/test-2) test-1 = plugin.performance.project$define_my_functions$test_1__3112@30e63c09 test-2 = plugin.performance.project$define_my_functions$test_2__3114@24ae6e0a Given this, are there any forms that are genuinely top-level from the compiler's point of view? I'm assuming defining functions like this is generally discouraged, but defining them inside of let-forms seems relatively common: (let [a 1] (defn get-a [] a)) = #=(var plugin.performance.project/get-a) (get-a) = 1 On 6 June 2013 09:57, Stuart Sierra the.stuart.sie...@gmail.com wrote: Hi Vincent, `defprotocol` is a top-level form, not really meant to be mixed with value-returning expressions like `fn`. Protocols are always global because of how they compile into Java interfaces. Here's one way to make it work, by defining a symbol instead of returning a function: (defmacro create-protocol [protocol symbol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (defn ~symbol [] (reify ~protocol-name ~implementation) (create-protocol [P (method [this])] constructor (method [this] (println method))) (method (constructor)) -S On Wednesday, June 5, 2013 9:16:05 AM UTC-4, Vincent wrote: I’m trying to write a macro that defines a protocol and a function that, when called, returns an implementation of that protocol. I’ve reduced the code to the following example: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (fn [] (reify ~protocol-name ~implementation) (let [f (create-protocol [P (method [this])] (method [this] (println method)))] (method (f))) The original code is more complicated, where the function will read a value from a file and, depending on that value, return the appropriate implementation of the protocol. When I run Clojure 1.5.1 on that code I get the following exception: Exception in thread main java.lang.**NullPointerException, compiling:(protocol.clj:7:9) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6567) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler$**FnMethod.parse(Compiler.java:**5139) at clojure.lang.Compiler$FnExpr.**parse(Compiler.java:3751) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.access$**100(Compiler.java:37) at clojure.lang.Compiler$LetExpr$**Parser.parse(Compiler.java:**5973) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler$**FnMethod.parse(Compiler.java:**5139) at clojure.lang.Compiler$FnExpr.**parse(Compiler.java:3751) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.eval(**Compiler.java:6616) at clojure.lang.Compiler.load(**Compiler.java:7064) at clojure.lang.Compiler.**loadFile(Compiler.java:7020) at clojure.main$load_script.**invoke(main.clj:294) at clojure.main$script_opt.**invoke(main.clj:356) at clojure.main$main.doInvoke(**main.clj:440) at clojure.lang.RestFn.invoke(**RestFn.java:408) at clojure.lang.Var.invoke(Var.**java:415) at clojure.lang.AFn.**applyToHelper(AFn.java:161
Re: NullPointerException when creating protocol in macro
On Wed, Jun 5, 2013 at 7:35 PM, Colin Fleming colin.mailingl...@gmail.comwrote: Given this, are there any forms that are genuinely top-level from the compiler's point of view? It's never explicitly enforced, just a consequence of how the compiler creates and loads Java classes. Generally, the things which compile directly to named Java classes -- defprotocol, deftype, defrecord -- may not work except as top-level forms, as Vincent discovered. -S -- -- 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.
Re: NullPointerException when creating protocol in macro
Legal but comparable to a hidden side effect with all the pitfalls that can derive from this. It's not a compiler issue, more a discipline issue. Having a helper macro like Stuart suggest is acceptable to me if it's called at top level, it's always done. There's less ambiguity. Using def/defn in a function is less desirable, the definition/redefinition occurs when you call the fn and it may occur at less desirable times or could be hard to spot. If you need a local fn, let-fn is exactly for this purpose. The scope is limited to the let-fn body. Luc P. *`defprotocol` is a top-level form...* This is interesting, and it's something I've wondered about. As far as I can tell, there's really no distinction between top-level forms and other forms, for example this is legal and works: (defn define-my-functions [] (defn test-1 [] 1) (defn test-2 [] 2)) = #=(var plugin.performance.project/define-my-functions) test-1 = Unbound: #'plugin.performance.project/test-1 test-2 = Unbound: #'plugin.performance.project/test-2 (define-my-functions) = #=(var plugin.performance.project/test-2) test-1 = plugin.performance.project$define_my_functions$test_1__3112@30e63c09 test-2 = plugin.performance.project$define_my_functions$test_2__3114@24ae6e0a Given this, are there any forms that are genuinely top-level from the compiler's point of view? I'm assuming defining functions like this is generally discouraged, but defining them inside of let-forms seems relatively common: (let [a 1] (defn get-a [] a)) = #=(var plugin.performance.project/get-a) (get-a) = 1 On 6 June 2013 09:57, Stuart Sierra the.stuart.sie...@gmail.com wrote: Hi Vincent, `defprotocol` is a top-level form, not really meant to be mixed with value-returning expressions like `fn`. Protocols are always global because of how they compile into Java interfaces. Here's one way to make it work, by defining a symbol instead of returning a function: (defmacro create-protocol [protocol symbol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (defn ~symbol [] (reify ~protocol-name ~implementation) (create-protocol [P (method [this])] constructor (method [this] (println method))) (method (constructor)) -S On Wednesday, June 5, 2013 9:16:05 AM UTC-4, Vincent wrote: I’m trying to write a macro that defines a protocol and a function that, when called, returns an implementation of that protocol. I’ve reduced the code to the following example: (defmacro create-protocol [protocol implementation] (let [[protocol-name signature] protocol] `(do (defprotocol ~protocol-name ~signature) (fn [] (reify ~protocol-name ~implementation) (let [f (create-protocol [P (method [this])] (method [this] (println method)))] (method (f))) The original code is more complicated, where the function will read a value from a file and, depending on that value, return the appropriate implementation of the protocol. When I run Clojure 1.5.1 on that code I get the following exception: Exception in thread main java.lang.**NullPointerException, compiling:(protocol.clj:7:9) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6567) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler$**FnMethod.parse(Compiler.java:**5139) at clojure.lang.Compiler$FnExpr.**parse(Compiler.java:3751) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6558) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6548) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.access$**100(Compiler.java:37) at clojure.lang.Compiler$LetExpr$**Parser.parse(Compiler.java:**5973) at clojure.lang.Compiler.**analyzeSeq(Compiler.java:6560) at clojure.lang.Compiler.analyze(**Compiler.java:6361) at clojure.lang.Compiler.analyze(**Compiler.java:6322) at clojure.lang.Compiler$**BodyExpr$Parser.parse(** Compiler.java:5708) at clojure.lang.Compiler$**FnMethod.parse(Compiler.java:**5139
what is the issue: NullPointerException com.mongodb.DBCursor._check (DBCursor.java:365) for congomongo
I use a mongodb which use sharding, so I connect to mongos. but when I query like: (fetch :locations) NullPointerException com.mongodb.DBCursor._check (DBCursor.java:365) there is error if the use (fetch :locations :one? true) it works. anyone know what is going on? I use version [congomongo 0.4.1], is it driver issue or usage issue? -- -- 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.
what is the issue: NullPointerException com.mongodb.DBCursor._check (DBCursor.java:365) for congomongo
I use a mongodb which use sharding, so I connect to mongos. but when I query like: (fetch :locations) NullPointerException com.mongodb.DBCursor._check (DBCursor.java:365) there is error if the use (fetch :locations :one? true) it works. anyone know what is going on? I use version [congomongo 0.4.1], is it driver issue or usage issue? -- -- 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.
Re: clj-logging-config, lein2 and AOT compilation == NullPointerException
I haven't really found out what the problem is - and haven't been looking into it - but I put a small clojure app together to replicate the issue. You can find it on dropbox[1] I've also updated the issue I had opened on the clj-logging-config github issues page [2] If you're keen on debugging this, just grab the project on dropbox, extract somewhere and compile it: lein with-profile production compile :all Then try to start the server like so: lein trampoline with-profile production run -m logging-tests.core 4000 You should have a big fat exception right on your terminal. [1] https://dl.dropbox.com/u/6251992/logging-tests.zip [2] https://github.com/malcolmsparks/clj-logging-config/issues/15 On Tuesday, September 4, 2012 2:57:21 PM UTC+10, Leonardo Borges wrote: Hi all, I've been debugging an issue in my Clojure app deployed on Heroku and after some time I finally tracked it down to what appears to be an issue when AOT compiling the project while using clj-logging-config [1] It works without any issues if I let Clojure compile my namespaces on the fly. As soon as I AOT compile, I can't run my jetty server any longer. This led me to open an issue [2] with clj-logging-config where you can find some extra info on my setup. I'm posting this here in the hopes someone has been through this before and that the solution is something trivial I've overlooked. [1] https://github.com/malcolmsparks/clj-logging-config [2] https://github.com/malcolmsparks/clj-logging-config/issues/15 Thanks, Leonardo Borges www.leonardoborges.com -- 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
clj-logging-config, lein2 and AOT compilation == NullPointerException
Hi all, I've been debugging an issue in my Clojure app deployed on Heroku and after some time I finally tracked it down to what appears to be an issue when AOT compiling the project while using clj-logging-config [1] It works without any issues if I let Clojure compile my namespaces on the fly. As soon as I AOT compile, I can't run my jetty server any longer. This led me to open an issue [2] with clj-logging-config where you can find some extra info on my setup. I'm posting this here in the hopes someone has been through this before and that the solution is something trivial I've overlooked. [1] https://github.com/malcolmsparks/clj-logging-config [2] https://github.com/malcolmsparks/clj-logging-config/issues/15 Thanks, Leonardo Borges www.leonardoborges.com -- 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
NullPointerException
Hi! I have a problem. With that code: ; === ; ex 1.17 multiply (defn ex1_17 [] (defn double [x] (+ x x)) (defn halve [x] (/ x 2)) (defn * [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1) (println (* 5 5)) ) (ex1_17 ) I gave that exception: Exception in thread main java.lang.NullPointerException, compiling: (D:\workprivate\ll\1\src\first.clj:3) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyze(Compiler.java:6223) at clojure.lang.Compiler.eval(Compiler.java:6515) at clojure.lang.Compiler.load(Compiler.java:6952) at clojure.lang.Compiler.loadFile(Compiler.java:6912) at clojure.main$load_script.invoke(main.clj:283) at clojure.main$script_opt.invoke(main.clj:343) at clojure.main$main.doInvoke(main.clj:427) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: 25) at java.lang.reflect.Method.invoke(Method.java:597) at com.intellij.rt.execution.application.AppMain.main(AppMain.java: 120) Caused by: java.lang.NullPointerException at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4774) at clojure.lang.Compiler$DefExpr.emit(Compiler.java:418) at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5659) at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5215) at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5069) at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3600) at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4233) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3732) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453) ... 24 more Could you tell me where I 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
Re: NullPointerException
Hi, Look at your parenthesis. You did not close your first function. Antoine 2012/5/17 Sargash gerby...@gmail.com Hi! I have a problem. With that code: ; === ; ex 1.17 multiply (defn ex1_17 [] (defn double [x] (+ x x)) (defn halve [x] (/ x 2)) (defn * [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1) (println (* 5 5)) ) (ex1_17 ) I gave that exception: Exception in thread main java.lang.NullPointerException, compiling: (D:\workprivate\ll\1\src\first.clj:3) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyze(Compiler.java:6223) at clojure.lang.Compiler.eval(Compiler.java:6515) at clojure.lang.Compiler.load(Compiler.java:6952) at clojure.lang.Compiler.loadFile(Compiler.java:6912) at clojure.main$load_script.invoke(main.clj:283) at clojure.main$script_opt.invoke(main.clj:343) at clojure.main$main.doInvoke(main.clj:427) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: 25) at java.lang.reflect.Method.invoke(Method.java:597) at com.intellij.rt.execution.application.AppMain.main(AppMain.java: 120) Caused by: java.lang.NullPointerException at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4774) at clojure.lang.Compiler$DefExpr.emit(Compiler.java:418) at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5659) at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5215) at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5069) at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3600) at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4233) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3732) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453) ... 24 more Could you tell me where I 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 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
Re: NullPointerException
On Thu, May 17, 2012 at 10:55 AM, eniotna eniotn...@gmail.com wrote: Look at your parenthesis. You did not close your first function. some day we'll have the technology to let the compiler tell us that, instead of spewing some horrible, pointless, stack trace? -- 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
Re: NullPointerException
Furthermore, The syntax you're using is not correct. If you want to define functions inside your function ex1_17, use letfn. Something along the line: (defn ex1_17 [] (letfn [(double [x] (+ x x)) (halve [x] (/ x 2)) (mult [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1)] (println (mult 5 5 I prefer not to mess with the default function so i redefined your * by mult Antoine 2012/5/17 eniotna eniotn...@gmail.com Hi, Look at your parenthesis. You did not close your first function. Antoine 2012/5/17 Sargash gerby...@gmail.com Hi! I have a problem. With that code: ; === ; ex 1.17 multiply (defn ex1_17 [] (defn double [x] (+ x x)) (defn halve [x] (/ x 2)) (defn * [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1) (println (* 5 5)) ) (ex1_17 ) I gave that exception: Exception in thread main java.lang.NullPointerException, compiling: (D:\workprivate\ll\1\src\first.clj:3) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyze(Compiler.java:6223) at clojure.lang.Compiler.eval(Compiler.java:6515) at clojure.lang.Compiler.load(Compiler.java:6952) at clojure.lang.Compiler.loadFile(Compiler.java:6912) at clojure.main$load_script.invoke(main.clj:283) at clojure.main$script_opt.invoke(main.clj:343) at clojure.main$main.doInvoke(main.clj:427) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: 25) at java.lang.reflect.Method.invoke(Method.java:597) at com.intellij.rt.execution.application.AppMain.main(AppMain.java: 120) Caused by: java.lang.NullPointerException at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4774) at clojure.lang.Compiler$DefExpr.emit(Compiler.java:418) at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5659) at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5215) at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5069) at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3600) at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4233) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3732) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453) ... 24 more Could you tell me where I 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 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
Re: NullPointerException
2012/5/17 Raoul Duke rao...@gmail.com On Thu, May 17, 2012 at 10:55 AM, eniotna eniotn...@gmail.com wrote: Look at your parenthesis. You did not close your first function. some day we'll have the technology to let the compiler tell us that, emacs told me. But i'm sure some other editors can tell you that too. instead of spewing some horrible, pointless, stack trace? indeed. -- 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 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
Re: NullPointerException
The redefinition of functions somehow is spooking the compiler. But if you're at the REPL you should be seeing these warnings (are you doing AOT compile?) WARNING: double already refers to: #'clojure.core/double in namespace: user, being replaced by: #'user/double WARNING: * already refers to: #'clojure.core/* in namespace: user, being replaced by: #'user/* Clojure 1.2 will compile regardless; later versions will produce the NPE. There's nothing wrong with your parens or your use of local functions. I just changed double to doubl and * to x and it all works fine. The stack trace isn't pretty but the warnings would've helped, so it's good to try things at the REPL. On Wednesday, May 16, 2012 3:25:20 PM UTC-7, Sargash wrote: Hi! I have a problem. With that code: ; === ; ex 1.17 multiply (defn ex1_17 [] (defn double [x] (+ x x)) (defn halve [x] (/ x 2)) (defn * [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1) (println (* 5 5)) ) (ex1_17 ) I gave that exception: Exception in thread main java.lang.NullPointerException, compiling: (D:\workprivate\ll\1\src\first.clj:3) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyze(Compiler.java:6223) at clojure.lang.Compiler.eval(Compiler.java:6515) at clojure.lang.Compiler.load(Compiler.java:6952) at clojure.lang.Compiler.loadFile(Compiler.java:6912) at clojure.main$load_script.invoke(main.clj:283) at clojure.main$script_opt.invoke(main.clj:343) at clojure.main$main.doInvoke(main.clj:427) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: 25) at java.lang.reflect.Method.invoke(Method.java:597) at com.intellij.rt.execution.application.AppMain.main(AppMain.java: 120) Caused by: java.lang.NullPointerException at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4774) at clojure.lang.Compiler$DefExpr.emit(Compiler.java:418) at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5659) at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5215) at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5069) at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3600) at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4233) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3732) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453) ... 24 more Could you tell me where I 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
Re: NullPointerException
There's nothing wrong is a pretty strong statement. It works, but it is definitely the wrong way to do things. Using a letfn, or external helper functions, is a much better approach. On May 17, 12:19 pm, Armando Blancas abm221...@gmail.com wrote: The redefinition of functions somehow is spooking the compiler. But if you're at the REPL you should be seeing these warnings (are you doing AOT compile?) WARNING: double already refers to: #'clojure.core/double in namespace: user, being replaced by: #'user/double WARNING: * already refers to: #'clojure.core/* in namespace: user, being replaced by: #'user/* Clojure 1.2 will compile regardless; later versions will produce the NPE. There's nothing wrong with your parens or your use of local functions. I just changed double to doubl and * to x and it all works fine. The stack trace isn't pretty but the warnings would've helped, so it's good to try things at the REPL. On Wednesday, May 16, 2012 3:25:20 PM UTC-7, Sargash wrote: Hi! I have a problem. With that code: ; === ; ex 1.17 multiply (defn ex1_17 [] (defn double [x] (+ x x)) (defn halve [x] (/ x 2)) (defn * [a b] (cond (= b 0) 0 (even? b) (* (double a) (halve b)) :else (+ a (* a (- b 1) (println (* 5 5)) ) (ex1_17 ) I gave that exception: Exception in thread main java.lang.NullPointerException, compiling: (D:\workprivate\ll\1\src\first.clj:3) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.access$100(Compiler.java:37) at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455) at clojure.lang.Compiler.analyze(Compiler.java:6262) at clojure.lang.Compiler.analyze(Compiler.java:6223) at clojure.lang.Compiler.eval(Compiler.java:6515) at clojure.lang.Compiler.load(Compiler.java:6952) at clojure.lang.Compiler.loadFile(Compiler.java:6912) at clojure.main$load_script.invoke(main.clj:283) at clojure.main$script_opt.invoke(main.clj:343) at clojure.main$main.doInvoke(main.clj:427) at clojure.lang.RestFn.invoke(RestFn.java:408) at clojure.lang.Var.invoke(Var.java:415) at clojure.lang.AFn.applyToHelper(AFn.java:161) at clojure.lang.Var.applyTo(Var.java:532) at clojure.main.main(main.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java: 39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImp l.java: 25) at java.lang.reflect.Method.invoke(Method.java:597) at com.intellij.rt.execution.application.AppMain.main(AppMain.java: 120) Caused by: java.lang.NullPointerException at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4774) at clojure.lang.Compiler$DefExpr.emit(Compiler.java:418) at clojure.lang.Compiler$BodyExpr.emit(Compiler.java:5659) at clojure.lang.Compiler$FnMethod.doEmit(Compiler.java:5215) at clojure.lang.Compiler$FnMethod.emit(Compiler.java:5069) at clojure.lang.Compiler$FnExpr.emitMethods(Compiler.java:3600) at clojure.lang.Compiler$ObjExpr.compile(Compiler.java:4233) at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3732) at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453) ... 24 more Could you tell me where I 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
Re: NullPointerException
It's called Emacs + Paredit :-) On Thu, May 17, 2012 at 8:00 PM, Raoul Duke rao...@gmail.com wrote: some day we'll have the technology to let the compiler tell us that, instead of spewing some horrible, pointless, stack trace? -- Moritz Ulrich -- 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
Re: NullPointerException
There's nothing wrong is a pretty strong statement. LOL. Perhaps as strong as it is definitely the wrong way to do things? Jeez. Pedantry is the wrong way to welcome newbies to this board. -- 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
Re: NullPointerException
On Thu, May 17, 2012 at 12:52 PM, Armando Blancas abm221...@gmail.com wrote: Pedantry is the wrong way to welcome newbies to this board. stop with your pedantry about there must be no pedantry? -- 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
Re: NullPointerException
On Thursday, May 17, 2012 12:52:27 PM UTC-7, Armando Blancas wrote: There's nothing wrong is a pretty strong statement. LOL. Perhaps as strong as it is definitely the wrong way to do things? Jeez. Pedantry is the wrong way to welcome newbies to this board. Far from being pedantic, Alan's advice was extremely practical. Anyone with moderate Clojure experience will agree that letfn or helper functions are actually what the OP wants, rather than def inside def. As a newcomer, it's helpful to find out about these kinds of things as early as possible. Your original advice, that There's nothing wrong with [...] your use of local functions not only fails to convey the fact that the OP's approach is probably not what they want -- it's also just plain wrong. Those are not local functions: def always operates at 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
Re: NullPointerException
-- it's also just plain wrong. Those are not local functions: def always operates at top-level. Big deal. You see what I mean? Pedantry is contagious. -- 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
Re: NullPointerException
On Thu, May 17, 2012 at 1:25 PM, Armando Blancas abm221...@gmail.com wrote: -- it's also just plain wrong. Those are not local functions: def always operates at top-level. Big deal. You see what I mean? Pedantry is contagious. er, i should think it *is* a big deal: programming languages really don't give one much room / do give one plenty of rope to hang oneself by. (anybody remember the high-school thing where you have to write natural language instructions for somebody on how to make a peanut butter sandwich?) -- 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
Re: NullPointerException
On Thursday, May 17, 2012 1:25:45 PM UTC-7, Armando Blancas wrote: -- it's also just plain wrong. Those are not local functions: def always operates at top-level. Big deal. You see what I mean? Pedantry is contagious. Well, I guess if trying not to give newcomers blatantly false information is what you consider pedantry, then I'm all for it, and I'm glad to hear that it's contagious. Also, *plonk*. -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 2011, at 6:44 PM, Stuart Halloway wrote: Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 2011, at 8:47 PM, Alan Malloy wrote: (let [ns-obj (the-ns (doto 'clojure.test require)) the-var (intern ns-obj 'old-report)] (when-not (.hasRoot the-var) (intern ns-obj 'old-report clojure.test/report))) Seems to have the same effect as the defonce in some simple testing. Of course it's silly to use intern the second time: (.setRoot the-var clojure.test/report) would have been simpler. Thank you. You've made a user happy. (You meant .bindRoot rather than .setRoot, right?) - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. Let me know if you don't find a workaround -- I would still like to understand that NPE. Stu Stuart Halloway Clojure/core http://clojure.com -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 9, 2011, at 4:58 PM, Stuart Halloway wrote: Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. Let me know if you don't find a workaround -- I would still like to understand that NPE. It's all better now. Alan Malloy's fix worked fine on Clojure 1.2.1 and 1.3. - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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
NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
This is under clojure 1.2.0, 1.2.1, 1.3.0, though the error messages differ. Consider a trivial project that `uses` midje: (ns midje-aot.core (:use midje.sweet)) If it's aot-compiled, everything appears to go well: 1762 $ lein compile Copying 6 files to /Users/marick/src/midje-aot/lib Copying 1 file to /Users/marick/src/midje-aot/lib/dev Compiling midje-aot.core Compilation succeeded. But certain of the namespaces can't be loaded: 1766 $ lein repl REPL started; server listening on localhost port 40437 user= (require 'midje.semi-sweet) NullPointerException clojure.lang.Compiler.lookupVar (Compiler.java:6780) What could that exception mean? What's a starting point for debugging? - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
This is under clojure 1.2.0, 1.2.1, 1.3.0, though the error messages differ. Consider a trivial project that `uses` midje: (ns midje-aot.core (:use midje.sweet)) If it's aot-compiled, everything appears to go well: 1762 $ lein compile Copying 6 files to /Users/marick/src/midje-aot/lib Copying 1 file to /Users/marick/src/midje-aot/lib/dev Compiling midje-aot.core Compilation succeeded. But certain of the namespaces can't be loaded: 1766 $ lein repl REPL started; server listening on localhost port 40437 user= (require 'midje.semi-sweet) NullPointerException clojure.lang.Compiler.lookupVar (Compiler.java:6780) What could that exception mean? What's a starting point for debugging? The full stack trace: clojure.lang.Compiler.lookupVar (Compiler.java:6780) clojure.lang.Compiler.isMacro (Compiler.java:6260) clojure.lang.Compiler.macroexpand1 (Compiler.java:6315) clojure.lang.Compiler.macroexpand (Compiler.java:6381) clojure.lang.Compiler.eval (Compiler.java:6449) clojure.lang.Compiler.eval (Compiler.java:6454) clojure.lang.Compiler.eval (Compiler.java:6431) clojure.core/eval (core.clj:2795) midje.util.report__init.load (:4) midje.util.report__init.clinit (:-1) java.lang.Class.forName0 (Class.java:-2) java.lang.Class.forName (Class.java:247) Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: (when (= (class clojure.test/report) clojure.lang.MultiFn) (eval '(do (require 'clojure.test) (ns clojure.test) (defonce old-report clojure.test/report Not sure where the problem is yet, and I have no time to look further tonight, but perhaps this will help somebody track the root cause. Stu Stuart Halloway Clojure/core http://clojure.com -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 4:44 pm, Stuart Halloway stuart.hallo...@gmail.com wrote: This is under clojure 1.2.0, 1.2.1, 1.3.0, though the error messages differ. Consider a trivial project that `uses` midje: (ns midje-aot.core (:use midje.sweet)) If it's aot-compiled, everything appears to go well: 1762 $ lein compile Copying 6 files to /Users/marick/src/midje-aot/lib Copying 1 file to /Users/marick/src/midje-aot/lib/dev Compiling midje-aot.core Compilation succeeded. But certain of the namespaces can't be loaded: 1766 $ lein repl REPL started; server listening on localhost port 40437 user= (require 'midje.semi-sweet) NullPointerException clojure.lang.Compiler.lookupVar (Compiler.java:6780) What could that exception mean? What's a starting point for debugging? The full stack trace: clojure.lang.Compiler.lookupVar (Compiler.java:6780) clojure.lang.Compiler.isMacro (Compiler.java:6260) clojure.lang.Compiler.macroexpand1 (Compiler.java:6315) clojure.lang.Compiler.macroexpand (Compiler.java:6381) clojure.lang.Compiler.eval (Compiler.java:6449) clojure.lang.Compiler.eval (Compiler.java:6454) clojure.lang.Compiler.eval (Compiler.java:6431) clojure.core/eval (core.clj:2795) midje.util.report__init.load (:4) midje.util.report__init.clinit (:-1) java.lang.Class.forName0 (Class.java:-2) java.lang.Class.forName (Class.java:247) Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: (when (= (class clojure.test/report) clojure.lang.MultiFn) (eval '(do (require 'clojure.test) (ns clojure.test) (defonce old-report clojure.test/report Not sure where the problem is yet, and I have no time to look further tonight, but perhaps this will help somebody track the root cause. At least you could simplify this and avoid using eval, by using clojure.core/intern directly instead of trying to get the compiler to believe you're in that namespace. Grabbing the source for the defonce macro, here's a draft of how I might rewrite this to avoid eval: (let [ns-obj (the-ns (doto 'clojure.test require)) the-var (intern ns-obj 'old-report)] (when-not (.hasRoot the-var) (intern ns-obj 'old-report clojure.test/report))) Seems to have the same effect as the defonce in some simple testing. -- 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
Re: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 6:46 pm, Alan Malloy a...@malloys.org wrote: On Nov 8, 4:44 pm, Stuart Halloway stuart.hallo...@gmail.com wrote: This is under clojure 1.2.0, 1.2.1, 1.3.0, though the error messages differ. Consider a trivial project that `uses` midje: (ns midje-aot.core (:use midje.sweet)) If it's aot-compiled, everything appears to go well: 1762 $ lein compile Copying 6 files to /Users/marick/src/midje-aot/lib Copying 1 file to /Users/marick/src/midje-aot/lib/dev Compiling midje-aot.core Compilation succeeded. But certain of the namespaces can't be loaded: 1766 $ lein repl REPL started; server listening on localhost port 40437 user= (require 'midje.semi-sweet) NullPointerException clojure.lang.Compiler.lookupVar (Compiler.java:6780) What could that exception mean? What's a starting point for debugging? The full stack trace: clojure.lang.Compiler.lookupVar (Compiler.java:6780) clojure.lang.Compiler.isMacro (Compiler.java:6260) clojure.lang.Compiler.macroexpand1 (Compiler.java:6315) clojure.lang.Compiler.macroexpand (Compiler.java:6381) clojure.lang.Compiler.eval (Compiler.java:6449) clojure.lang.Compiler.eval (Compiler.java:6454) clojure.lang.Compiler.eval (Compiler.java:6431) clojure.core/eval (core.clj:2795) midje.util.report__init.load (:4) midje.util.report__init.clinit (:-1) java.lang.Class.forName0 (Class.java:-2) java.lang.Class.forName (Class.java:247) Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: (when (= (class clojure.test/report) clojure.lang.MultiFn) (eval '(do (require 'clojure.test) (ns clojure.test) (defonce old-report clojure.test/report Not sure where the problem is yet, and I have no time to look further tonight, but perhaps this will help somebody track the root cause. At least you could simplify this and avoid using eval, by using clojure.core/intern directly instead of trying to get the compiler to believe you're in that namespace. Grabbing the source for the defonce macro, here's a draft of how I might rewrite this to avoid eval: (let [ns-obj (the-ns (doto 'clojure.test require)) the-var (intern ns-obj 'old-report)] (when-not (.hasRoot the-var) (intern ns-obj 'old-report clojure.test/report))) Seems to have the same effect as the defonce in some simple testing. Of course it's silly to use intern the second time: (.setRoot the-var clojure.test/report) would have been simpler. And of course I don't know whether this will fix the problem, but it seems like it should at least simplify 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
Re: SICP sqrt function generates unexpected NullPointerException
+1 hangs with Clojure 1.2.1 in Slimes REPL on Java 1.6.0_26 (Ubuntu) -- 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
Re: SICP sqrt function generates unexpected NullPointerException
An infinite loop on large inputs is unrelated to his null-pointer problem. As SICP makes clear, the imprecision of floating-point arithmetic means this particular algorithm will not terminate for large inputs. That is, rounding errors stop it from making progress when the numbers are large and the deltas small. If a larger (or adaptive) delta were chosen, this would succeed. On Oct 16, 4:52 am, Timo Grodzinski timo.grodzin...@googlemail.com wrote: +1 hangs with Clojure 1.2.1 in Slimes REPL on Java 1.6.0_26 (Ubuntu) -- 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
SICP sqrt function generates unexpected NullPointerException
Hi everyone, I've encountered an unexpected NullPointerException while translating some early SICP code into Clojure 1.3.0. In particular, I'm implementing the iterative sqrt procedure from section 1.1.7. Here's my code: (defn square [x] (* x x)) (defn abs [x] (cond ( x 0) (- x) :else x)) (defn average [x y] (/ (+ x y) 2)) (defn sqrt ([x] (sqrt 1.0 x)) ([guess x] (letfn [(good-enough? [guess] ( (abs (- (square guess) x)) 0.001)) (improve [guess] (average guess (/ x guess)))] (if (good-enough? guess) guess (recur (improve guess) x) Rather mysteriously, this works correctly for inputs less than roughly (square 2718.259...); anything larger throws a NullPointerException clojure.lang.Numbers.lt (Numbers.java:3693). Any ideas? -- 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
Re: SICP sqrt function generates unexpected NullPointerException
With 1.3/OSX this code worked up to: user= (sqrt 1) 100.0 and then hanged here: user= (sqrt 10) ~ $ On Oct 13, 7:04 pm, Alan O'Donnell alan.m.odonn...@gmail.com wrote: Hi everyone, I've encountered an unexpected NullPointerException while translating some early SICP code into Clojure 1.3.0. In particular, I'm implementing the iterative sqrt procedure from section 1.1.7. Here's my code: (defn square [x] (* x x)) (defn abs [x] (cond ( x 0) (- x) :else x)) (defn average [x y] (/ (+ x y) 2)) (defn sqrt ([x] (sqrt 1.0 x)) ([guess x] (letfn [(good-enough? [guess] ( (abs (- (square guess) x)) 0.001)) (improve [guess] (average guess (/ x guess)))] (if (good-enough? guess) guess (recur (improve guess) x) Rather mysteriously, this works correctly for inputs less than roughly (square 2718.259...); anything larger throws a NullPointerException clojure.lang.Numbers.lt (Numbers.java:3693). Any ideas? -- 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
Re: SICP sqrt function generates unexpected NullPointerException
Armando, I get the same behavior as you with Clojure 1.2.1. But if I lein dep Clojure 1.3.0, I'm back to NullPointerExceptions. -- 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
Re: NullPointerException on disj
On May 27, 1:10 am, Allen Johnson akjohnso...@gmail.com wrote: Hey everyone. I was playing around with the protocols/deftype stuff and ran into a weird NullPointerException when calling the satisfies? function. Seems to only happen with a java.lang.Object instance. Clojure 1.2.0-master-SNAPSHOT user= (defprotocol Greeter (greet [this])) Greeter user= (satisfies? Greeter nil) false user= (satisfies? Greeter ) false user= (satisfies? Greeter (Object.)) java.lang.NullPointerException (NO_SOURCE_FILE:0) Narrowed it down to this function: ;; core_deftype.clj (defn find-protocol-impl [protocolx] (if (instance? (:on-interfaceprotocol) x) x (let [c (class x) impl #(get (:implsprotocol) %)] (or (impl c) (and c (or (first (remove nil? (map impl (butlast (super-chain c) (when-let [t (reduce pref (filter impl (disj (supers c) Object)))] (impl t)) (impl Object))) More specifically, here: (disj (supers c) Object) Since in this case, `c` is java.lang.Object, supers returns nil which disj doesn't seem to like. Shouldn't disj handle nil gracefully? Yes, could you please enter a ticket for this? Thanks, Rich -- 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
NullPointerException on disj
Hey everyone. I was playing around with the protocols/deftype stuff and ran into a weird NullPointerException when calling the satisfies? function. Seems to only happen with a java.lang.Object instance. Clojure 1.2.0-master-SNAPSHOT user= (defprotocol Greeter (greet [this])) Greeter user= (satisfies? Greeter nil) false user= (satisfies? Greeter ) false user= (satisfies? Greeter (Object.)) java.lang.NullPointerException (NO_SOURCE_FILE:0) Narrowed it down to this function: ;; core_deftype.clj (defn find-protocol-impl [protocol x] (if (instance? (:on-interface protocol) x) x (let [c (class x) impl #(get (:impls protocol) %)] (or (impl c) (and c (or (first (remove nil? (map impl (butlast (super-chain c) (when-let [t (reduce pref (filter impl (disj (supers c) Object)))] (impl t)) (impl Object))) More specifically, here: (disj (supers c) Object) Since in this case, `c` is java.lang.Object, supers returns nil which disj doesn't seem to like. Shouldn't disj handle nil gracefully? Thanks, Allen -- 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
Clojars.org artifact upload issue - NullPointerException
Hi,
I am trying to upload a JAR to Clojars.org but I am getting
NullPointerException. Can somebody help me understand what's going on?
The log is below:
D:\projects\hgrepos\jettify\jettify-parent\jettify-java\targetscp
pom.xml jettify-java-0.2.jar cloj...@clojars.org:
Welcome to Clojars, kumarshantanu!
pom.xml
100% 2539 2.5KB/s 00:00
jettify-
java-0.2.jar
100% 3780 3.7KB/s 00:00
Error: transaction rolled back: null
java.lang.Exception: transaction rolled back: null
at clojure.contrib.sql.internal
$throw_rollback__7448.invoke(internal.clj:135)
at clojure.contrib.sql.internal
$transaction_STAR___7451.invoke(internal.clj:162)
at clojars.db$add_jar__134$fn__137.invoke(db.clj:163)
at clojure.contrib.sql.internal
$with_connection_STAR___7428.invoke(internal.clj:98)
at clojars.db$add_jar__134.doInvoke(db.clj:162)
at clojure.lang.RestFn.invoke(RestFn.java:445)
at clojars.scp$finish_deploy__51.invoke(scp.clj:123)
at clojars.scp$nail__86.invoke(scp.clj:162)
at clojars.scp$_nailMain__93.invoke(scp.clj:174)
at clojars.scp.nailMain(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.martiansoftware.nailgun.NGSession.run(Unknown Source)
Caused by: java.lang.NullPointerException
at java.util.regex.Matcher.getTextLength(Matcher.java:1151)
at java.util.regex.Matcher.reset(Matcher.java:308)
at java.util.regex.Matcher.init(Matcher.java:228)
at java.util.regex.Pattern.matcher(Pattern.java:905)
at clojure.core$re_matcher__5789.invoke(core.clj:3143)
at clojure.core$re_matches__5803.invoke(core.clj:3175)
at clojars.db$check_and_add_group__128.invoke(db.clj:144)
at clojars.db$add_jar__134$fn__137$fn__139.invoke(db.clj:165)
at clojure.contrib.sql.internal
$transaction_STAR___7451.invoke(internal.clj:153)
... 13 more
The pom.xml has the following content:
project xmlns=http://maven.apache.org/POM/4.0.0; xmlns:xsi=http://
www.w3.org/2001/XMLSchema-instance
xsi:schemaLocation=http://maven.apache.org/POM/4.0.0
http://maven.apache.org/maven-v4_0_0.xsd;
modelVersion4.0.0/modelVersion
parent
groupIdorg.bitumenframework.jettify/groupId
artifactIdjettify-parent/artifactId
version0.2/version
/parent
artifactIdjettify-java/artifactId
packagingjar/packaging
version0.2/version
namejettify-java/name
urlhttp://code.google.com/p/bitumenframework//url
dependencies
dependency
groupIdorg.mortbay.jetty/groupId
artifactIdjetty/artifactId
version6.1.22/version
/dependency
dependency
groupIdjavax.servlet/groupId
artifactIdservlet-api/artifactId
version2.5/version
scopeprovided/scope
/dependency
dependency
groupIdjunit/groupId
artifactIdjunit/artifactId
version4.7/version
scopetest/scope
/dependency
dependency
groupIdorg.mortbay.jetty/groupId
artifactIdjetty-embedded/artifactId
version6.1.22/version
/dependency
dependency
groupIdorg.mortbay.jetty/groupId
artifactIdjsp-2.1-jetty/artifactId
version6.1.22/version
/dependency
dependency
groupIdorg.apache.httpcomponents/groupId
artifactIdhttpclient/artifactId
version4.0.1/version
scopetest/scope
/dependency
dependency
groupIdorg.bitumenframework.jettify/groupId
artifactIdjettify-test-support/artifactId
version0.2/version
scopetest/scope
/dependency
/dependencies
build
plugins
plugin
groupIdorg.apache.maven.plugins/groupId
artifactIdmaven-surefire-plugin/artifactId
configuration
systemProperties
property
namebasedir/name
value${basedir}/value
/property
/systemProperties
/configuration
/plugin
plugin
groupIdorg.mortbay.jetty/groupId
artifactIdjetty-maven-plugin/artifactId
/plugin
plugin
artifactIdmaven-compiler-plugin/artifactId
configuration
source1.5/source
target1.5/target
/configuration
/plugin
/plugins
/build
/project
Regards,
Shantanu
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Re: Clojars.org artifact upload issue - NullPointerException
Hi Shantanu, Shantanu Kumar kumar.shant...@gmail.com writes: artifactIdjettify-java/artifactId packagingjar/packaging version0.2/version namejettify-java/name urlhttp://code.google.com/p/bitumenframework//url You appear to not be specifying a groupId in your POM. Try adding one. Cheers, Alex -- 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 To unsubscribe, reply using remove me as the subject.
Re: Clojars.org artifact upload issue - NullPointerException
On Apr 2, 4:37 am, Alex Osborne a...@meshy.org wrote: Hi Shantanu, Shantanu Kumar kumar.shant...@gmail.com writes: artifactIdjettify-java/artifactId packagingjar/packaging version0.2/version namejettify-java/name urlhttp://code.google.com/p/bitumenframework//url You appear to not be specifying a groupId in your POM. Try adding one. It worked. Thanks! Regards, Shantanu -- 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 To unsubscribe, reply using remove me as the subject.
NullPointerException from #' et al.
Hi, out of curiosity, what is the reasoning behind this behavior (I'm pretty sure it is intended): (= nil 1) = false ( nil 1) ;; NullPointerException Same behavior for = = etc. Florian -- Florian Ebeling florian.ebel...@gmail.com -- 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
Re: NullPointerException from #' et al.
What do you think should be the boolean result of ( nil 1)? Since the inequality functions only work with Numbers, and nil is not a Number. The only way to make that work would be to impute some default numerical value to nil, which would probably introduce more problems than it solved. On Jan 14, 7:57 am, C. Florian Ebeling florian.ebel...@gmail.com wrote: Hi, out of curiosity, what is the reasoning behind this behavior (I'm pretty sure it is intended): (= nil 1) = false ( nil 1) ;; NullPointerException Same behavior for = = etc. Florian -- Florian Ebeling florian.ebel...@gmail.com -- 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
Re: NullPointerException from #' et al.
What do you think should be the boolean result of ( nil 1)? Since the inequality functions only work with Numbers, and nil is not a Number. The only way to make that work would be to impute some default numerical value to nil, which would probably introduce more problems than it solved. I agree. It only looks inconsistent when you assume nil is treated uniformly by these comparison function, which does not make sense. Sorry, this question was probably a tad stupid :) -- Florian Ebeling florian.ebel...@gmail.com -- 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
Re: NullPointerException from #' et al.
On Jan 14, 9:00 am, C. Florian Ebeling florian.ebel...@gmail.com wrote: What do you think should be the boolean result of ( nil 1)? Since the inequality functions only work with Numbers, and nil is not a Number. The only way to make that work would be to impute some default numerical value to nil, which would probably introduce more problems than it solved. I agree. It only looks inconsistent when you assume nil is treated uniformly by these comparison function, which does not make sense. Perhaps you should use compare, which doesn't have the numerical restriction and also works well with nil. -- 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
Re: NullPointerException from #' et al.
Also, it is consistent given that == is the numerical analogue to =, etc. -- 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
Re: NullPointerException from #' et al.
2010/1/15 C. Florian Ebeling florian.ebel...@gmail.com: I agree. It only looks inconsistent when you assume nil is treated uniformly by these comparison function, which does not make sense. I quite often wish to compare comparable objects that are not numbers and wrote some simple operators to do that: user= (? \a \b \c) true user= (? \c \b) false user= (? 1 nil) false user= (? nil 1) true Which would work in your situation... However if you are using numbers but sometimes encounter nil, then a better solution would be to use fnil, which is a function that returns a function that will substitute any nil arguments with some default value. This is very handy shorthand when you have nil data points that you want to treat as zero: user= ((fnil 0 0 ) nil 1) true user= ((fnil 0 0 ) 1 nil) false You can find the implementation for both object comparator operators and fnil from my github if you are interested: http://github.com/timothypratley/strive/blob/master/clj/timothypratley/extensions.clj Regards, Tim. -- 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
NullPointerException with defmacro and none without?!
Hi all, I'm new to Clojure and I'm playing around with Qt Jambi, which works as expected, until I started to use a self written macro. Now I don't know if this is just a problem I don't see (probably) or if it is a bug in Clojure. I have the following sample code (I hope this is readable when posted. Otherwise I'll use something like pastebin): (ns a.namespace.sample (:gen-class) (:import (com.trolltech.qt.gui QApplication QMainWindow))) (defmacro RunQt [args body] `( (try (QApplication/initialize (into-array [~args])) (catch RuntimeException e# (println e#))) ~...@body (QApplication/exec))) (defn -main [args] (RunQt args (let [mainWindow (QMainWindow.)] (.show mainWindow (defn -main2 [args] (try (QApplication/initialize (into-array [args])) (catch RuntimeException e (println e))) (let [mainWindow (QMainWindow.)] (.show mainWindow)) (QApplication/exec)) ; (-main ) ; (-main2 ) Now both -main and -main2 work as expected, they show a simple Window with nothing in it. So far so good. But after I close the Window, - main throws the following exception: Exception in thread main java.lang.NullPointerException (qtest.clj:0) at clojure.lang.Compiler.eval(Compiler.java:4543) at clojure.lang.Compiler.load(Compiler.java:4857) at clojure.lang.Compiler.loadFile(Compiler.java:4824) at clojure.main$load_script__5833.invoke(main.clj:206) at clojure.main$script_opt__5864.invoke(main.clj:258) at clojure.main$main__5888.doInvoke(main.clj:333) at clojure.lang.RestFn.invoke(RestFn.java:413) at clojure.lang.Var.invoke(Var.java:346) at clojure.lang.AFn.applyToHelper(AFn.java:173) at clojure.lang.Var.applyTo(Var.java:463) at clojure.main.main(main.java:39) Caused by: java.lang.NullPointerException at a.namespace.sample$_main__8.invoke(qtest.clj:16) at a.namespace.sample$eval__20.invoke(qtest.clj:29) at clojure.lang.Compiler.eval(Compiler.java:4532) ... 10 more whereas -main2 does not. Now they both look to my newbie eyes the same, except the code of -main is generated by a macro. This is the same if I compile the code. The uncompiled version I started with (paths omitted for better readability): java -cp clojure.jar;qtjambi-4.5.2_01.jar;qtjambi-win32-msvc2005-4.5.2_01.jar clojure.main qtest.clj I have this behavior under WinXP and 2k, with Java RE 1.5.x and with JDK 1.6.0_16, Clojure 1.0.0 and the latest Qt Jambi. Am I just missing something totally fundamental and this is expected behavior? I fiddled with this code for I don't know how long, tried this and that but cannot figure out where this NullPointerException is coming from. Any help would be appreciated. Thanks and greetings --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: NullPointerException with defmacro and none without?!
Hi, Am 01.09.2009 um 17:44 schrieb Sir Diddymus: (defmacro RunQt [args body] `( (try (QApplication/initialize (into-array [~args])) (catch RuntimeException e# (println e#))) ~...@body (QApplication/exec))) You have to wrap the try and QApplication/exec call into a `do`: (do (try ) (Qapplication/exec)) (defn -main2 [args] (try (QApplication/initialize (into-array [args])) (catch RuntimeException e (println e))) (let [mainWindow (QMainWindow.)] (.show mainWindow)) (QApplication/exec)) `defn` does the `do`-wrapping for you. You get a NPE, because your macro basically expands to ((try ...) (QApplication/exec)). So the return value of the try is used as function which is called on the result of the QApp/exec. Now obviously QApp/initialize returns nil. Hence the exception. Sincerely Meikel smime.p7s Description: S/MIME cryptographic signature
NullPointerException in Compiler.java
Hi, could Rich or someone knowledgeable look into this (reflection
related?) NullPointerException in Compiler.java.
I think it's either a bug or at least should provide a better error
message, but I don't have any time to look deeper into it..
Thanks, Jon
-
I was using clojure-1.0 but looks likely to still be a problem with
the trunk.
* compile the below java class and make available on classpath:
package mypkg;
public class MyClass {
public MyClass() {
}
Object myField;
}
* then this line of clojure throws a NullPointerException:
(set! (.myField (mypkg.MyClass.)) test)
-
When myField definition is private, as above, (or completely removed)
the NullPointerException
occurs. When you add 'public' to myField definition, the problem goes
away..
Looking at InstanceFieldExpr in Compiler.java (approx line 900)..
the emit() and emitUnboxed() functions guard against 'field' being
null
if(targetClass != null field != null)
but the emitAssign() function doesn't
if(targetClass != null)
and therefore in this case field.getType() causes the
NullPointerException
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Re: NullPointerException in Compiler.java
On Jul 3, 5:27 am, jon superuser...@googlemail.com wrote:
Hi, could Rich or someone knowledgeable look into this (reflection
related?) NullPointerException in Compiler.java.
I think it's either a bug or at least should provide a better error
message, but I don't have any time to look deeper into it..
Thanks, Jon
-
I was using clojure-1.0 but looks likely to still be a problem with
the trunk.
* compile the below java class and make available on classpath:
package mypkg;
public class MyClass {
public MyClass() {
}
Object myField;
}
* then this line of clojure throws a NullPointerException:
(set! (.myField (mypkg.MyClass.)) test)
-
When myField definition is private, as above, (or completely removed)
the NullPointerException
occurs. When you add 'public' to myField definition, the problem goes
away..
Looking at InstanceFieldExpr in Compiler.java (approx line 900)..
the emit() and emitUnboxed() functions guard against 'field' being
null
if(targetClass != null field != null)
but the emitAssign() function doesn't
if(targetClass != null)
and therefore in this case field.getType() causes the
NullPointerException
Fixed - thanks for the report:
http://www.assembla.com/spaces/clojure/tickets/142-Bug--Compile-time-NPE-on-set!-of-non-existent-field
RIch
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Re: clojure.contrib.test-is/run-tests throws NullPointerException w/ invalid args
On May 5, 2:05 pm, Timo Mihaljov noid@gmail.com wrote: When clojure.contrib.test-is/run-tests is given an invalid argument, it throws a NullPointerException: Fixed! -SS --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
clojure.contrib.test-is/run-tests throws NullPointerException w/ invalid args
When clojure.contrib.test-is/run-tests is given an invalid argument, it throws a NullPointerException: user= (use 'clojure.contrib.test-is) nil user= (run-tests 'asdf) java.lang.RuntimeException: java.lang.NullPointerException (NO_SOURCE_FILE:0) The issue seems harmless in a simple case like this, but in a more complex case the error is quite hard to debug for two reasons: - When the stack trace is longer it's not immediately obvious what caused the NullPointerException. - The error can be caused by a simple typo so it's quite easy to miss when reading the code because the code reads aloud correctly. Having something like 'clojure.contrib.test-is.NamespaceException: No such namespace asdf' would make the source of the error easy to find. I found this bug by having a namespace called errorr (deliberate typo), and accidentally spelled it correctly as error in the argument to run-tests. You might say that I got what I deserved for picking a clever Web2.0 name like that (and I would agree :), but keep in mind that any other typo would have worked and could have been as hard to find. As an example, here's the the stack trace that one typo gave me. Exception in thread main java.lang.RuntimeException: java.lang.NullPointerException (run-tests.clj:0) at clojure.lang.Compiler.eval(Compiler.java:4543) at clojure.lang.Compiler.load(Compiler.java:4857) at clojure.lang.Compiler.loadFile(Compiler.java:4824) at clojure.main$load_script__5833.invoke(main.clj:206) at clojure.main$script_opt__5864.invoke(main.clj:258) at clojure.main$main__5888.doInvoke(main.clj:333) at clojure.lang.RestFn.invoke(RestFn.java:413) at clojure.lang.Var.invoke(Var.java:346) at clojure.lang.AFn.applyToHelper(AFn.java:173) at clojure.lang.Var.applyTo(Var.java:463) at clojure.main.main(main.java:39) Caused by: java.lang.RuntimeException: java.lang.NullPointerException at clojure.lang.LazySeq.seq(LazySeq.java:46) at clojure.lang.RT.seq(RT.java:436) at clojure.core$seq__3133.invoke(core.clj:103) at clojure.core$spread__3240.invoke(core.clj:383) at clojure.core$spread__3240.invoke(core.clj:384) at clojure.core$apply__3243.doInvoke(core.clj:390) at clojure.lang.RestFn.invoke(RestFn.java:443) at clojure.contrib.test_is$run_tests__4789.doInvoke(test_is.clj:914) at clojure.lang.RestFn.invoke(RestFn.java:413) at errorr.engine.gfx.tests$run__7.invoke(tests.clj:5) at user$eval__10.invoke(run-tests.clj:2) at clojure.lang.Compiler.eval(Compiler.java:4532) ... 10 more Caused by: java.lang.NullPointerException at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768) at clojure.lang.Namespace.find(Namespace.java:129) at clojure.core$find_ns__4309.invoke(core.clj:2347) at clojure.core$the_ns__4321.invoke(core.clj:2371) at clojure.core$ns_name__4325.invoke(core.clj:2376) at clojure.contrib.test_is$fn__4660.invoke(test_is.clj:586) at clojure.lang.MultiFn.invoke(MultiFn.java:157) at clojure.contrib.test_is$test_ns__4785.invoke(test_is.clj:896) at clojure.core$map__3815$fn__3817.invoke(core.clj:1503) at clojure.lang.LazySeq.seq(LazySeq.java:41) ... 21 more -- Timo --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: clojure.contrib.test-is/run-tests throws NullPointerException w/ invalid args
On May 5, 2:05 pm, Timo Mihaljov noid@gmail.com wrote: When clojure.contrib.test-is/run-tests is given an invalid argument, it throws a NullPointerException: Yes, I'm aware of this, will try to fix. -SS --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Not really a NullPointerException, and repl lines
Clojure user= (nil (println asd) ) java.lang.NullPointerException (NO_SOURCE_FILE:1) user= This seems like an odd error to get here. Couldn't it say something like invalid function as first value? It also made me wonder, would it be possible to have a line counter inside the REPL, and just use repl as the filename? The repl could optionally show a line-number on every line. For that matter, it could even be interesting to do development from within the repl, if you could save to source. Is it possible to generate the source code from say a function or a namespace? -Jeff --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
