Parameters: verify the new cyclicWrap library function

The implementation should cover all integral data types,
both signed and signed, over the entire value domain.

Verify that by testing the bounds and the complex computation path

tests/15library.tests

@@ -53,6 +53,11 @@ return: 0
 END
 
 
+TEST "Cyclic wrapping number domain" CyclicWrap_test <<END
+return: 0
+END
+
+
 TEST "Deleter function collection" DelStash_test <<END
 return: 0
 END

tests/lib/cyclic-wrap-test.cpp

@@ -0,0 +1,144 @@
+/*
+  CyclicWrap(Test)  -  verify cyclically wrapping number domain
+
+   Copyright (C)
+     2026,            Hermann Vosseler <Ichthyostega@web.de>
+
+  **Lumiera** is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation; either version 2 of the License, or (at your
+  option) any later version. See the file COPYING for further details.
+
+* *****************************************************************/
+
+/** @file util-floordiv-test.cpp
+ ** unit test \ref CyclicWrap_test
+ */
+
+
+#include "test/run.hpp"
+#include "lib/util-quant.hpp"
+#include "lib/util.hpp"
+#include "test/diagnostic-output.hpp"//////////////////TODO
+//#include "lib/format-cout.hpp"
+//#include "lib/format-string.hpp"
+
+using ::Test;
+//using util::isnil;
+//using util::_Fmt;
+using util::isLimited;
+
+
+namespace util {
+namespace test {
+  
+  
+  
+  namespace{ // Test helpers...
+    
+    template<typename NUM>
+    constexpr NUM _MAX = std::numeric_limits<NUM>::max();
+    
+    template<typename NUM>
+    constexpr NUM _MIN = std::numeric_limits<NUM>::lowest();
+    
+  } // (End) Test helpers
+  
+  
+  
+  /******************************************************************//**
+   * @test Demonstrate and verify a cyclic wrapping numeric domain.
+   *     - show the wrapping behaviour with simple numbers
+   *     - verify the behaviour pattern for all integer types (signed / unsigned)
+   *     - verify the computation works at the very bounds of the domain
+   *     - verify the most difficult path with a negative minVal,
+   *       and the smallest number in the domain
+   * @todo add coverage for floating-point numbers
+   * @see util::cyclicWrap
+   * @see parameter-scale-test.cpp
+   */
+  class CyclicWrap_test : public Test
+    {
+      
+      virtual void
+      run (Arg)
+        {
+          simpleDemonstration();
+          
+          verifyIntegerTypes<int>();
+          verifyIntegerTypes<uint>();
+          verifyIntegerTypes<int8_t>();
+          verifyIntegerTypes<uint8_t>();
+          verifyIntegerTypes<int16_t> ();
+          verifyIntegerTypes<uint16_t>();
+          verifyIntegerTypes<int32_t> ();
+          verifyIntegerTypes<uint32_t>();
+          verifyIntegerTypes<int64_t> ();
+          verifyIntegerTypes<uint64_t>();
+        }
+      
+      
+      void
+      simpleDemonstration ()
+        {
+          CHECK (10 == cyclicWrap (10,10,15));
+          CHECK (11 == cyclicWrap (11,10,15));
+          CHECK (12 == cyclicWrap (12,10,15));
+          CHECK (13 == cyclicWrap (13,10,15));
+          CHECK (14 == cyclicWrap (14,10,15));
+          CHECK (10 == cyclicWrap (15,10,15));
+          CHECK (11 == cyclicWrap (16,10,15));
+          CHECK (12 == cyclicWrap (17,10,15));
+          CHECK (13 == cyclicWrap (18,10,15));
+          CHECK (14 == cyclicWrap (19,10,15));
+          CHECK (10 == cyclicWrap (20,10,15));
+          
+          CHECK (10 == cyclicWrap ( 0,10,15));
+          CHECK (14 == cyclicWrap (-1,10,15));
+        }
+      
+      
+      template<typename I>
+      void
+      verifyIntegerTypes ()
+        {
+          const I LOWER(-100);   // note: expected to wrap for unsigned types
+          const I UPPER(LOWER+5);
+          
+          auto cyc = [&](I val){ return cyclicWrap (I(val), LOWER,UPPER); };
+          
+          CHECK (LOWER   == cyc(LOWER+0) );
+          CHECK (LOWER+1 == cyc(LOWER+1) );
+          CHECK (LOWER+2 == cyc(LOWER+2) );
+          CHECK (LOWER+3 == cyc(LOWER+3) );
+          CHECK (LOWER+4 == cyc(LOWER+4) );
+          CHECK (LOWER   == cyc(LOWER+5) );
+          
+          CHECK (LOWER   == cyc(LOWER-5) );
+          CHECK (LOWER+1 == cyc(LOWER-4) );
+          CHECK (LOWER+2 == cyc(LOWER-3) );
+          CHECK (LOWER+3 == cyc(LOWER-2) );
+          CHECK (LOWER+4 == cyc(LOWER-1) );
+          
+          
+          CHECK (isLimited (LOWER, cyc(_MAX<I>), UPPER));
+          CHECK (isLimited (LOWER, cyc(_MIN<I>), UPPER));
+          
+          CHECK (isLimited (LOWER, cyc(_MAX<I>-1), UPPER));
+          CHECK (isLimited (LOWER, cyc(_MIN<I>+1), UPPER));
+          
+          I dist = LOWER - _MIN<I>;  // guaranteed to be positive and representable in-domain
+          I step = (dist / 5) * 5;   // the next applicable grid point
+          I excess = dist - step;
+          I offset = 5 - excess;     // flip orientation (since the input val lies below LOWER)
+          
+          CHECK (LOWER + offset == cyc(_MIN<I>) );
+        }
+    };
+  
+  
+  
+  LAUNCHER (CyclicWrap_test, "unit common");
+  
+  
+}} // namespace util::test

wiki/thinkPad.ichthyo.mm

@@ -86141,7 +86141,7 @@ class ScaleRegistry
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+<linktarget COLOR="#49a8d6" DESTINATION="ID_636669321" ENDARROW="Default" ENDINCLINATION="87;46;" ID="Arrow_ID_1613615444" SOURCE="ID_945572666" STARTARROW="None" STARTINCLINATION="260;14;"/>
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+<node BACKGROUND_COLOR="#accdc3" COLOR="#3f4015" CREATED="1789314221349" FOLDED="true" ID="ID_63841523" MODIFIED="1789423414551" TEXT="Floatingpoint: Nicht-handhabbare Bereiche beachten...">
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+<node BACKGROUND_COLOR="#accdc3" COLOR="#3f4015" CREATED="1789314739520" FOLDED="true" ID="ID_900911623" MODIFIED="1789423604616" TEXT="Erl&#xe4;uterung der L&#xf6;ungsstrategie">
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@@ -86769,13 +86770,14 @@ Prop.1: dist%3       1  2  0  1  2  0
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+<linktarget COLOR="#f8263e" DESTINATION="ID_921584380" ENDARROW="Default" ENDINCLINATION="-16;141;" ID="Arrow_ID_244758209" SOURCE="ID_380512260" STARTARROW="None" STARTINCLINATION="198;10;"/>
+</node>
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 <node BACKGROUND_COLOR="#aff8e9" COLOR="#338800" CREATED="1789340798664" HGAP="15" ID="ID_1175604381" MODIFIED="1789340850559" TEXT="damit k&#xf6;nnte ich implementieren..." VSHIFT="18">
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-<node BACKGROUND_COLOR="#e0ceaa" COLOR="#690f14" CREATED="1789340871908" ID="ID_380512260" MODIFIED="1789342452121" STYLE="fork" TEXT="die Erl&#xe4;uterung f&#xfc;r den Unsigned-Fall ist zu knapp">
+<node BACKGROUND_COLOR="#e0ceaa" COLOR="#690f14" CREATED="1789340871908" ID="ID_380512260" MODIFIED="1789423600852" STYLE="fork" TEXT="die Erl&#xe4;uterung f&#xfc;r den Unsigned-Fall ist zu knapp">
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@@ -86784,7 +86786,7 @@ Prop.1: dist%3       1  2  0  1  2  0
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@@ -86806,13 +86808,14 @@ Prop.1: dist%3       1  2  0  1  2  0
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 </node>
-<node CREATED="1789360000999" ID="ID_879348844" MODIFIED="1789360029799" TEXT="die Limit-Definition sollte direkt bei der cyclicWrap-Funktion selber definiert sein"/>
+<node COLOR="#435e98" CREATED="1789360000999" ID="ID_879348844" MODIFIED="1789423630533" TEXT="die Limit-Definition sollte direkt bei der cyclicWrap-Funktion selber definiert sein">
+<icon BUILTIN="yes"/>
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-<node CREATED="1789258816860" ID="ID_1706182584" MODIFIED="1789258941151" TEXT="Policy-based Design erscheint die sauberste L&#xf6;sung">
+<node BACKGROUND_COLOR="#d2beaf" COLOR="#5c4d6e" CREATED="1789258816860" ID="ID_1706182584" MODIFIED="1789423431524" TEXT="Policy-based Design erscheint die sauberste L&#xf6;sung">
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@@ -86822,8 +86825,70 @@ Prop.1: dist%3       1  2  0  1  2  0
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+<icon BUILTIN="hourglass"/>
+</node>
+<node BACKGROUND_COLOR="#c8c0b6" COLOR="#435e98" CREATED="1789313641938" ID="ID_1271083241" MODIFIED="1789423457169" TEXT="zun&#xe4;chst gen&#xfc;gt eine generische Library-funktion als Delegate">
+<icon BUILTIN="forward"/>
+</node>
+</node>
+<node COLOR="#338800" CREATED="1789423486714" ID="ID_253445206" MODIFIED="1789438207120" TEXT="neue Implementierung">
+<icon BUILTIN="button_ok"/>
+<node CREATED="1789423493685" ID="ID_1410459624" MODIFIED="1789423506223" TEXT="entwickelt ausgehend von der naiven &#xbb;modulus&#xab;-L&#xf6;sung"/>
+<node BACKGROUND_COLOR="#accdc3" COLOR="#3f4015" CREATED="1789423507714" ID="ID_945572666" MODIFIED="1789423613866" TEXT="zu einer generischen L&#xf6;sung ausgebaut &#x27f5; Claude">
+<arrowlink COLOR="#49a8d6" DESTINATION="ID_636669321" ENDARROW="Default" ENDINCLINATION="87;46;" ID="Arrow_ID_1613615444" STARTARROW="None" STARTINCLINATION="260;14;"/>
+<icon BUILTIN="wizard"/>
+</node>
+<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1789423635808" ID="ID_840921741" MODIFIED="1789438193575" TEXT="Testabdeckung &#x2014; Grenzf&#xe4;lle">
+<icon BUILTIN="pencil"/>
+<node CREATED="1789428970477" ID="ID_1439061940" MODIFIED="1789429004081" TEXT="habe gestern schon gesehen: f&#xfc;r sich sind util::flordiv | wrap wohl &#x201e;wasserdicht&#x201c;">
+<node CREATED="1789429005712" ID="ID_1890368766" MODIFIED="1789429031093" TEXT="die Division liefert stets einen kleineren Quotient als der Dividend"/>
+<node CREATED="1789429032161" ID="ID_1469836197" MODIFIED="1789429058156" TEXT="die Korrektur-Logik arbeitet &#xbb;gl&#xfc;cklicherweise&#xab; stets zur Dom&#xe4;ne nach innen"/>
+<node COLOR="#338800" CREATED="1789433766523" ID="ID_167005830" MODIFIED="1789433779815" TEXT="dies in UtilFloordiv_test dokumentieren">
+<icon BUILTIN="button_ok"/>
+<node COLOR="#435e98" CREATED="1789433789808" ID="ID_538605241" MODIFIED="1789433827387" TEXT="jeweils an die Domain-Ober/Untergrenze gehen"/>
+<node COLOR="#435e98" CREATED="1789433801119" ID="ID_1533251912" MODIFIED="1789433827418" TEXT="durch 1, 2 und 5 teilen"/>
+<node COLOR="#435e98" CREATED="1789433808102" ID="ID_1210053047" MODIFIED="1789433827419" TEXT="Vorzeichen wechseln"/>
+<node COLOR="#435e98" CREATED="1789433812805" ID="ID_1425318347" MODIFIED="1789433827421" TEXT="auch f&#xfc;r uint, int64_t, int8_t"/>
+</node>
+</node>
+<node COLOR="#338800" CREATED="1789437807095" ID="ID_932126209" MODIFIED="1789437907066" TEXT="zun&#xe4;chst eine einfache Demonstration (als Dokumentation)">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      .... ich k&#246;nnte mir denken, da&#223; mancher Leser das Konzept nicht gleich versteht, deshalb ist ein solches einfaches Beispiel nie verkehrt
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+  </body>
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+<icon BUILTIN="button_ok"/>
+<node BACKGROUND_COLOR="#c8c0b6" COLOR="#435e98" CREATED="1789437929974" ID="ID_532498668" MODIFIED="1789438198770" TEXT="die eigentliche Test-Funktion als Template">
+<icon BUILTIN="idea"/>
+</node>
+<node COLOR="#338800" CREATED="1789437943780" ID="ID_1291965296" MODIFIED="1789438178462" TEXT="konstruiere das Test-Beispiel &#xbb;trickreich&#xab;">
+<icon BUILTIN="button_ok"/>
+<node CREATED="1789437965201" ID="ID_1576393662" MODIFIED="1789437977028" TEXT="so da&#xdf; es sich f&#xfc;r Signed und Unsigned gut testen l&#xe4;&#xdf;t"/>
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+<node CREATED="1789438002860" ID="ID_1338563274" MODIFIED="1789438069296" TEXT="&#x27f9; sollte die zyklische Dom&#xe4;ne in den negativen Bereich legen">
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+<node CREATED="1789438082993" ID="ID_1576673426" MODIFIED="1789438091635" TEXT="aber trotzdem noch sicher in die Dom&#xe4;ne passen"/>
+<node CREATED="1789438092936" ID="ID_1900067766" MODIFIED="1789438108922" TEXT="und f&#xfc;r Signed ist dann der Offset garantiert repr&#xe4;sentierbar"/>
+<node CREATED="1789438111305" ID="ID_1260779668" MODIFIED="1789438125620" TEXT="und zwar grade f&#xfc;r den problematischen Fall unter der Untergrenze"/>
+</node>
+</node>
+<node COLOR="#338800" CREATED="1789438130012" ID="ID_1945361876" MODIFIED="1789438175874" TEXT="teste die Dom&#xe4;nen-Grenzen auf valides Ergebnis (in der zyklischen Domain)">
+<icon BUILTIN="button_ok"/>
+</node>
+<node COLOR="#338800" CREATED="1789438158204" ID="ID_527867911" MODIFIED="1789438175875" TEXT="rechne explizit den Wert f&#xfc;r die Domain-Untergrenze nach">
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+</node>
+</node>
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