Documentation, add more examples (#13825)

lib/pure/concurrency/cpuinfo.nim

@@ -49,9 +49,6 @@ when defined(haiku):
 proc countProcessors*(): int {.rtl, extern: "ncpi$1".} =
   ## returns the number of the processors/cores the machine has.
   ## Returns 0 if it cannot be detected.
-  ##
-  ## .. code-block:: nim
-  ##   block: doAssert countProcessors() >= 0
   when defined(windows):
     type
       SYSTEM_INFO {.final, pure.} = object
@@ -98,3 +95,8 @@ proc countProcessors*(): int {.rtl, extern: "ncpi$1".} =
   else:
     result = sysconf(SC_NPROCESSORS_ONLN)
   if result <= 0: result = 0
+
+
+runnableExamples:
+  block:
+    doAssert countProcessors() > 0

lib/pure/osproc.nim

@@ -293,6 +293,7 @@ proc errorHandle*(p: Process): FileHandle {.rtl, extern: "nosp$1",
 proc countProcessors*(): int {.rtl, extern: "nosp$1".} =
   ## Returns the number of the processors/cores the machine has.
   ## Returns 0 if it cannot be detected.
+  ## It is implemented just calling `cpuinfo.countProcessors`.
   result = cpuinfo.countProcessors()
 
 proc execProcesses*(cmds: openArray[string],

lib/pure/stats.nim

@@ -327,13 +327,14 @@ runnableExamples:
       var statistics: RunningStat  ## Must be "var"
       statistics.push(@[1.0, 2.0, 1.0, 4.0, 1.0, 4.0, 1.0, 2.0])
       doAssert statistics.n == 8
-      doAssert statistics.mean() is SomeFloat
-      doAssert statistics.variance() is SomeFloat
-      doAssert statistics.varianceS() is SomeFloat
-      doAssert statistics.skewness() is SomeFloat
-      doAssert statistics.skewnessS() is SomeFloat
-      doAssert statistics.kurtosis() is SomeFloat
-      doAssert statistics.kurtosisS() is SomeFloat
+      template `===`(a, b: float): bool = (abs(a - b) < 1e-9)
+      doAssert statistics.mean() === 2.0
+      doAssert statistics.variance() === 1.5
+      doAssert statistics.varianceS() === 1.714285714285715
+      doAssert statistics.skewness() === 0.8164965809277261
+      doAssert statistics.skewnessS() === 1.018350154434631
+      doAssert statistics.kurtosis() === -1.0
+      doAssert statistics.kurtosisS() === -0.7000000000000008
 
 
 when isMainModule: