How to check Clojure, macro specs?

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• Why does my random function doesn't always work?

  My function is supposed to give me 6 numbers, but to avoid zero and should not repeat any number, but sometimes it brings me 0 or repeated numbers

  (defn function
    []
    (def lista (sort (take 6 (repeatedly #(rand-int 60)))))
    (loop []
      (when (or (= (contains? (set lista) 0) true) (< (count (set lista)) 6))
        (def lista (sort (take 6 (repeatedly #(rand-int 60)))))))
    (println lista))
  
• Clojure spec - test check OutOfMemoryError

  I'm trying to do property-based testing for this simple function:

  (defn distinct-kw-keys
    [maps]
    (->> (map keys maps)
         (flatten)
         (filter keyword?)
         (distinct)
         (vec)))
  

  ... using fdef and check:

  (require '[clojure.spec.alpha :as s]
           '[clojure.spec.test.alpha :as test])
  
  (s/fdef distinct-kw-keys
    :args (s/cat :maps (s/coll-of map?))
    :ret  (s/coll-of keyword?
                     :kind vector?
                     :distinct true))
  
  (test/check `distinct-kw-keys)
  

  Calling test/check terminates after a while throwing OutOfMemoryError:

  Exception in thread "Timer-1" Error printing return value (OutOfMemoryError) at clojure.test.check.generators/choose$fn (generators.cljc:260). Java heap space etc.

  I can't figure out what's the problem here. Function and specs seem to work fine, e.g.

  (require '[clojure.spec.gen.alpha :as gen])
  
  (s/valid?
   (s/coll-of keyword?
              :kind vector?
              :distinct true)
   (distinct-kw-keys
    (gen/generate
     (s/gen
      (s/coll-of map?))))) ;; => true
  
• current session error opening REPL in emacs with CIDER

  I've been following a tutorial and hit an error where there wasn't one in the book. I have reinstalled leinigen, updated java and reinstalled cider on emacs.

  But doesn't seem to help and I can't find this error message online. Running M-x "cider-jack-in" to open a REPL gives me the error message:

  "Symbol’s function definition is void: sesman-current-sessions"

  and I can't figure out what's causing this, any help is gratefully received.
• define a 2D constant array in a C macro

  I would like to load a static array in memory, used as a convolution kernel in a later loop, in C99 and later. I tried that:

  /** This is the outer product of
   * filter[5] = { 1.0f / 16.0f, 4.0f / 16.0f, 6.0f / 16.0f, 4.0f / 16.0f, 1.0f / 16.0f };
   * computed at once, outside of the pixels loops, saving 25 multiplications per pixel
   * */
  #define filter[5][5] { {0.00390625f, 0.015625f, 0.0234375f, 0.015625f, 0.00390625f}, \
                         {0.01562500f, 0.062500f, 0.0937500f, 0.062500f, 0.01562500f}, \
                         {0.02343750f, 0.093750f, 0.1406250f, 0.093750f, 0.02343750f}, \
                         {0.01562500f, 0.062500f, 0.0937500f, 0.062500f, 0.01562500f}, \
                         {0.00390625f, 0.015625f, 0.0234375f, 0.015625f, 0.00390625f} }
  

  GCC 8 complains:

  error: expected expression before « { » token
   #define filter { {0.00390625f, 0.015625f, 0.0234375f, 0.015625f, 0.00390625f}, \
  

  I have found how to load 1D vectors, but how to do that with 2D ?

  Edit

  The ultimate goal is to build a SIMD array from it:

  static const __m128 filter_sse[5][5] = { { _mm_set1_ps(filter[0][0]),
                                           ... },
                                             ... };
  

  and using a static const float filter[5][5] makes it complain about trying to set a constant with non-constant values.
• Using implicit declaration for hiding helper functions

  As specified here C makes implicit declaration of functions it does not know. So I tend to make use of it for hiding implementation details. I defined the following header file:

  #ifndef TEST_H
  #define TEST_H
  
  #define PRINT(msg) \
      do{\
          _print_info_msg(msg);\
          printf(msg);\
      } while(0)
  
  #endif //TEST_H
  

  and the corresponding C file:

  #include "test.h"
  
  void _print_info_msg(const char *str){
      printf("INFO: printing %s\n", str);
  }
  

  When compiling this code compiler warns that implicit declaration of function ‘_print_info_msg’ [-Wimplicit-function-declaration].

  The benefit of this I can see is that we do not directly expose helper function (_print_info_msg) to anyone who includes test.h yet we make use of linker so _print_info_msg implementation is provided.

  I'm not sure about this approach... Does it even make sense? To me it looks kind of ugly, but this is the only "use-case" I could find for implicit declaration.
• Define a function which function name is masked by a macro

  Sometimes, it can be handy to mask a function by a macro of same name. In this contrived example, the macros makes it possible to insert additional verification while calling function().

  int function(int i);
  
  #define function(i)  ( assert(i>0), function(i) )
  

  Other more common usages make the macro translate into faster code, like a direct table entry point, for improved performance. In all cases, the goal is to preserve the symbol of same name in the library, to ensure it exists and can be invoked from the library by another program without requiring the *.h (typically from a wrapper in a language different from C).

  In the corresponding unit, defining function() now has a problem : function is now a macros. So int function(int i) { ... } will be expanded, and fail pretty badly.

  The solution to this problem is simple : just #undef function before the definition, and then implement the function.

  All is fine, except that ...

  If, in a later section of the same unit, another function invokes function(), it will now invoke the symbol directly, instead of the macro in the *.h, thus losing the extra-functionalities provided by the macros, which might be undesirable.

  Another work-around to this issue is available in gcc, using compiler extension #pragma push_macro. It works, but is pretty much ugly, adding a minimum of 3 lines around the function definition, which doesn't help for readability. And this is without counting portability shenanigans, which will add more complexity.

  Yet, masking a function with a macro of same name isn't new. I'm pretty sure I've read books suggesting this design as far back as C90 standard libraries.

  I'm suspecting a better solution to this problem might exist. Any idea ?
• Clojure Spec : map? failing because spec thinks my data-structure is a vector?

  I'm trying to validate a large clojure data-structure in Spec.

  I'm getting a failure on this part :

  {:pageName "HelloWorld" :pageType ::workPage :cells ["Hello World" "How are you?"]}
  

  using this :

  (s/def ::WorkPage (s/keys :req-un [::pageName ::pageType ::cells]))
  

  Which fails with this message (from expound)

  {:pageName "HelloWorld", :pageType :assemblage.db/workPage, :cells ["Hello World" "How are you?"]} db.js:52:1
  false db.js:54:1
  -- Spec failed --------------------
  
    [:pageName "HelloWorld"]
    ^^^^^^^^^^^^^^^^^^^^^^^^
  
  should satisfy
  
    map?
  

  If I run the above spec by itself in the repl it works.

  But in context (in a clojurescript file) it looks almost as if the data-structure is being converted into a vector somewhere before it gets tested.

  Has anyone seen anything like this before?

  Could it be the result of doing this in ClojureScript? Is this some weird javascript coercion leaking up and biting me?

  Or is it likely to be something completely different?
• How to accept only ordered collections in spec

  How can I make a spec that accepts only sequential (i.e. order-preserving) collections?

  For example

  cljs.user=> (s/def ::path (s/+ number?))                                                                                                                                                                                 
  :cljs.user/path
  cljs.user=> (s/explain ::path [])                                                                                                                                                                                                                           
  val: () fails spec: :cljs.user/path predicate: number?,  Insufficient input
  :cljs.spec.alpha/spec  :cljs.user/path
  :cljs.spec.alpha/value  [] 
  cljs.user=> (s/explain ::path [1 2 3])                                                                                                                                                                                                                      
  Success!
  

  That's as expected, but in the same time, pay attention to the order

  cljs.user=> #{1 2 3}
  #{1 3 2}
  cljs.user=> (s/explain ::path #{1 2 3})                                                                                                                                                                                                                     
  Success!
  

  And that doesn't appear to make any sense. So a secondary question:

  Why sequence-related expressions (cat, *, +, ?) in spec accept sequence-breaking collections?

  UPD I've messed up sequential/ordered distinction in original question. Cleaned up terminology.
• How to make sure clojure generator generates all the given values in a collection instead of it picking up a random value?

  Hello Clojure experts..!,

  I want to create a generative test and make sure my test runs for all the test inputs that i want to run.

  Example: Below are my test inputs which i want to run for all five samples against my test case

  (gen/elements ["clojure" "haskell" "erlang" "scala" "python"])

  When i use: (gen/one-of (gen/elements ["clojure" "haskell" "erlang" "scala" "python"]), it can pick one element randomly but not guaranteed that it picks all my samples and test my function under test.

      (ns spec.gen-test.explore
      (:require [clojure.test                    :refer :all]
                [clojure.spec                    :as spec]
                [clojure.test.check.generators   :as gen]
                [clojure.test.check.properties   :as prop :include-macros true]
                [clojure.test.check.clojure-test :refer [defspec]]))
  (def languages-set #{"clojure" "haskell" "erlang" "scala" "python"})
  
  (spec/def ::jvm-languages 
    (spec/and string?
      languages-set))
  
  ;;Generative test case for jvm-languages spec:
  (defspec jvm-languages-generative-test
     5
    (prop/for-all [language (gen/elements ["clojure" "haskell" "erlang" "scala" "python"])]
                  (println "Testing for language:" language)
                  (spec/valid? ::jvm-languages language)))
  (run-tests)
  
  Output: 
  #'spec.gen-test.explore/jvm-languages-generative-test
  Testing for language: scala
  Testing for language: haskell
  Testing for language: erlang
  Testing for language: erlang
  Testing for language: scala
  {:result true, :num-tests 5, :seed 1533232724897, :test-var "jvm-languages-generative-test"}
  

  Is there a way that i can ask clojure to test my function under test with all the samples that i want to test with?
• Why is my Scalacheck test with a custom Generator failing after discarding many cases, and how do I fix this?

  I am a newbie with Scala and I am writing my first Scalacheck suite.

  I have a data structure in my program that essentially looks like a (List[Double], List[Double]) which is well-formed only if each element of _1 is strictly greater than the corresponding element of _2.

  Since it's slightly more complicated in practice (although for the purpose of this MWE we can pretend there's all there is to it), I've written a custom generator for it.

  I then added two trivial tests (including the most trivial of all, 1 == 1) and in both cases the tests fail, with the messageGave up after only XX passed tests. YYY tests were discarded.

  Why is it, and how do I fix it?

  Attached is my test suite and the output.

  ---

  package com.foo.bar
  
  import org.scalacheck._
  import Prop._
  import Arbitrary._
  
  object FooSpecification extends Properties("FooIntervals") {
  
    type FooIntervals = (List[Double], List[Double])
  
    /* This is supposed to be a tuple of lists s.t. each element of _1
     *  is < the corresponding element of _2
     * 
     *  e.g. (List(1,3,5), List(2,4,6))
     */
  
    implicit def arbInterval : Arbitrary[FooIntervals] =
      Arbitrary {
        /**
          * Yields a pair (low, high) s.t. low < high
          */
        def GenPair : Gen[(Double, Double)] = for {
          low <- arbitrary[Double]
          high <- arbitrary[Double].suchThat(_ > low)
        } yield (low, high)
  
        /**
          * Yields (List(x_1,...,x_n), List(y_1,...,y_n))
          * where x_i < y_i forall i and 1 <= n < 20
          */
        for {
          n <- Gen.choose(1,20)
          pairs : List[(Double, Double)] <- Gen.containerOfN[List, (Double, Double)](n, GenPair)
        } yield ((pairs.unzip._1, pairs.unzip._2))
      }
  
    property("1 == 1") = forAll {
      (b1: FooIntervals)
      =>
      1 == 1
    }
  
    property("_1.head < _2.head") = forAll {
      (b1: FooIntervals)
      =>
      b1._1.head < b1._2.head
    }
  }
  

  ---

  [info] ! FooIntervals.1 == 1: Gave up after only 32 passed tests. 501 tests were discarded.
  [info] ! FooIntervals._1.head < _2.head: Gave up after only 28 passed tests. 501 tests were discarded.
  [info] ScalaTest
  [info] Run completed in 1 second, 519 milliseconds.
  [info] Total number of tests run: 0
  [info] Suites: completed 0, aborted 0
  [info] Tests: succeeded 0, failed 0, canceled 0, ignored 0, pending 0
  [info] No tests were executed.
  [error] Failed: Total 1, Failed 1, Errors 0, Passed 0
  [error] Failed tests:
  [error]     com.foo.bar.FooSpecification