From 1e657acbffae269cd22ac2f3a9fe45fb824639bb Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Sun, 9 Sep 2018 03:23:17 +0200
Subject: [PATCH] TreeExplorer: refactor Transformer to employ the improved
 wrapping style

...step by step switch over to the new usage pattern.
Transformer should be the blueprint for all other functor usages.


The reworked solutions behaves as expected;
we see two functor invocations; the outer functor, which does
the argument adaptation, is allocated in heap memory
---
 src/lib/iter-tree-explorer.hpp            | 21 ++++++++-------
 src/lib/wrapper.hpp                       |  2 ++
 tests/library/iter-tree-explorer-test.cpp |  1 +
 wiki/thinkPad.ichthyo.mm                  | 33 ++++++++++++++++++++---
 4 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/src/lib/iter-tree-explorer.hpp b/src/lib/iter-tree-explorer.hpp
index 2bf94e392..b3a18bbe0 100644
--- a/src/lib/iter-tree-explorer.hpp
+++ b/src/lib/iter-tree-explorer.hpp
@@ -793,32 +793,31 @@ namespace lib {
      * is adapted in a similar way as the "expand functor", so to detect and convert the
      * expected input on invocation.
      */
-    template<class SRC, class FUN>
+    template<class SRC, class RES>
     class Transformer
       : public SRC
       {
         static_assert(can_IterForEach<SRC>::value, "Lumiera Iterator required as source");
-        using _Traits = _FunTraits<FUN,SRC>;
-        using Res = typename _Traits::Res;
         
-        using TransformFunctor = typename _Traits::Functor;
-        using TransformedItem = wrapper::ItemWrapper<Res>;
+        using TransformFunctor = function<RES(SRC&)>;
+        using TransformedItem = wrapper::ItemWrapper<RES>;
         
         TransformFunctor trafo_;
         TransformedItem treated_;
         
       public:
-        using value_type = typename meta::TypeBinding<Res>::value_type;
-        using reference  = typename meta::TypeBinding<Res>::reference;
-        using pointer    = typename meta::TypeBinding<Res>::pointer;
+        using value_type = typename meta::TypeBinding<RES>::value_type;
+        using reference  = typename meta::TypeBinding<RES>::reference;
+        using pointer    = typename meta::TypeBinding<RES>::pointer;
         
         
         Transformer() =default;
         // inherited default copy operations
         
+        template<typename FUN>
         Transformer (SRC&& dataSrc, FUN&& transformFunctor)
           : SRC{move (dataSrc)}
-          , trafo_{forward<FUN> (transformFunctor)}
+          , trafo_{_FunTraits<FUN,SRC>::template adaptFunctor<SRC> (forward<FUN> (transformFunctor))}
           { }
         
         
@@ -1437,7 +1436,9 @@ namespace lib {
       auto
       transform (FUN&& transformFunctor)
         {
-          using ResCore = iter_explorer::Transformer<SRC, FUN>;
+          using Product = typename iter_explorer::_FunTraits<FUN,SRC>::Res;
+          
+          using ResCore = iter_explorer::Transformer<SRC, Product>;
           using ResIter = typename _DecoratorTraits<ResCore>::SrcIter;
           
           return TreeExplorer<ResIter> (ResCore {move(*this), forward<FUN>(transformFunctor)});
diff --git a/src/lib/wrapper.hpp b/src/lib/wrapper.hpp
index aa66db2fe..363274fb6 100644
--- a/src/lib/wrapper.hpp
+++ b/src/lib/wrapper.hpp
@@ -185,11 +185,13 @@ namespace wrapper {
       
       explicit
       ItemWrapper(TY const& o)
+        : created_(false)
         {
           build (o);
         }
       explicit
       ItemWrapper(TY && ro)
+        : created_(false)
         {
           build (std::move(ro));
         }
diff --git a/tests/library/iter-tree-explorer-test.cpp b/tests/library/iter-tree-explorer-test.cpp
index 588be76c4..914349475 100644
--- a/tests/library/iter-tree-explorer-test.cpp
+++ b/tests/library/iter-tree-explorer-test.cpp
@@ -517,6 +517,7 @@ namespace test{
                       .transform(multiply)
                       ;
           
+          CHECK (14 == *ii);
           CHECK (14 == *ii);
           ++ii;
           CHECK (12 == *ii);
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index a892bba72..bab370530 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -31200,8 +31200,8 @@
 </node>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536409302285" ID="ID_913930564" MODIFIED="1536409311669" TEXT="extrem komplexe Typen">
-<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536409302285" ID="ID_913930564" MODIFIED="1536455982782" TEXT="extrem komplexe Typen">
+<icon BUILTIN="pencil"/>
 <node CREATED="1536409316172" ID="ID_1468538186" MODIFIED="1536409340127" TEXT="Call-Traces sind nahezu unlesbar">
 <richcontent TYPE="NOTE"><html>
   <head>
@@ -31318,8 +31318,8 @@
 <node CREATED="1536451303308" ID="ID_1343290323" MODIFIED="1536451313142" TEXT="man kann sie mit dem Funktor aufrufen -&gt; Sig"/>
 <node CREATED="1536451313778" ID="ID_439029617" MODIFIED="1536451336475" TEXT="man kann sie mit Sig aufrufen -&gt; Arg, Ret"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536451345998" ID="ID_1853688774" MODIFIED="1536451360667" TEXT="Funktor-Konstruktor-Funktion">
-<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1536451345998" ID="ID_1853688774" MODIFIED="1536453357128" TEXT="Funktor-Konstruktor-Funktion">
+<icon BUILTIN="button_ok"/>
 <node CREATED="1536451365731" ID="ID_552359289" MODIFIED="1536451394878" TEXT="f&#xfc;r Aufruf aus dem Konstruktor-Kontext">
 <richcontent TYPE="NOTE"><html>
   <head>
@@ -31358,6 +31358,31 @@
 </richcontent>
 </node>
 </node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536453317787" ID="ID_975974776" MODIFIED="1536453363634" TEXT="integrieren in...">
+<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1536453326978" ID="ID_1071395763" MODIFIED="1536453367022" TEXT="Transformer">
+<icon BUILTIN="button_ok"/>
+<node COLOR="#338800" CREATED="1536455906647" ID="ID_603515158" MODIFIED="1536455919470" TEXT="im Debugger beobachtet">
+<icon BUILTIN="button_ok"/>
+</node>
+<node CREATED="1536455920701" ID="ID_1992285034" MODIFIED="1536455938637" TEXT="&#xe4;u&#xdf;erer Funktor liegt im Heap">
+<icon BUILTIN="smily_bad"/>
+</node>
+<node CREATED="1536455947209" ID="ID_1054869208" MODIFIED="1536455959131" TEXT="innerer Funktor ist aber direkt dort eingebettet"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536453368676" ID="ID_1560078731" MODIFIED="1536453372397" TEXT="Filter">
+<icon BUILTIN="flag-yellow"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536453373605" ID="ID_1544724438" MODIFIED="1536453376828" TEXT="MutableFilter">
+<icon BUILTIN="flag-yellow"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536453408359" ID="ID_63715215" MODIFIED="1536453414663" TEXT="Anpassen an Expander">
+<icon BUILTIN="flag-yellow"/>
+</node>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1536453419141" ID="ID_564310637" MODIFIED="1536453427198" TEXT="vereinfachen">
+<icon BUILTIN="flag-yellow"/>
+</node>
 </node>
 </node>
 </node>