From 0d5f29446b52bebeccfa2937b39493d015ff3456 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Fri, 12 Oct 2018 01:07:13 +0200
Subject: [PATCH] TreeMutator: provide no-op implementation

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---
 src/lib/diff/tree-mutator-noop-binding.hpp | 30 +++++++++++++++++-----
 wiki/thinkPad.ichthyo.mm                   | 25 ++++++++++++------
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/src/lib/diff/tree-mutator-noop-binding.hpp b/src/lib/diff/tree-mutator-noop-binding.hpp
index a07c26fa3..c8fea45fb 100644
--- a/src/lib/diff/tree-mutator-noop-binding.hpp
+++ b/src/lib/diff/tree-mutator-noop-binding.hpp
@@ -70,18 +70,34 @@ namespace diff{
      * Diff binding for black holes, happily accepting anything.
      * @note absorbs and silently ignores any diff verb.
      */
-    template<class PAR>
     class BlackHoleMutation
-      : public PAR
+      : public TreeMutator
       {
         
-        
       public:
-        BlackHoleMutation (PAR&& chain)
-          : PAR{std::forward<PAR>(chain)}
-          { }
+        BlackHoleMutation () = default;
         
         
+        /* ==== TreeMutator API ==== */
+        
+        using Elm  = GenNode const&;
+        using Buff = TreeMutator::Handle;
+        
+        bool hasSrc()                override { return true; }  ///< always keen to do yet more
+        
+        bool injectNew (Elm)         override { return true; }  ///< pretend to inject a new element
+        bool matchSrc (Elm)          override { return true; }  ///< purport suitable element is waiting
+        bool acceptSrc (Elm)         override { return true; }  ///< claim to handle any diff task
+        bool accept_until (Elm)      override { return true; }  ///< profess to forward anywhere
+        bool findSrc (Elm)           override { return true; }  ///< sham to find anything
+        bool assignElm (Elm)         override { return true; }  ///< accept any assignment
+        
+        bool
+        mutateChild (Elm, Buff buff) override                   ///< bluff to care for children, while just reproducing ourselves
+          {
+            buff.create (BlackHoleMutation());
+            return true;
+          }
       };
     
     
@@ -91,7 +107,7 @@ namespace diff{
     inline auto
     Builder<PAR>::ignoreAllChanges()
     {
-      return chainedBuilder<BlackHoleMutation<PAR>>();
+      return Builder<BlackHoleMutation> (BlackHoleMutation{});
     }
     
     
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 8873e718f..9ca2edb50 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -16549,8 +16549,8 @@
 </node>
 <node CREATED="1539270808827" ID="ID_1352270227" MODIFIED="1539270817730" TEXT="f&#xfc;r TimelineGui">
 <linktarget COLOR="#a9b4c1" DESTINATION="ID_1352270227" ENDARROW="Default" ENDINCLINATION="117;0;" ID="Arrow_ID_1672775567" SOURCE="ID_1624846094" STARTARROW="None" STARTINCLINATION="117;0;"/>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294555064" HGAP="45" ID="ID_1365984217" MODIFIED="1539294575340" TEXT="Problem: diff ignorieren" VSHIFT="23">
-<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294555064" HGAP="45" ID="ID_1365984217" MODIFIED="1539299038616" TEXT="Problem: diff ignorieren" VSHIFT="23">
+<icon BUILTIN="messagebox_warning"/>
 <node CREATED="1539294576338" ID="ID_485684974" MODIFIED="1539294587881" TEXT="kann das auftreten....?">
 <icon BUILTIN="help"/>
 <node CREATED="1539294589200" ID="ID_1206613848" MODIFIED="1539294592657" TEXT="ja">
@@ -16579,10 +16579,10 @@
 <node CREATED="1539294678444" ID="ID_934706379" MODIFIED="1539294693604" TEXT="TreeMutator scheitert per Default">
 <icon BUILTIN="broken-line"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294698801" ID="ID_1533611583" MODIFIED="1539294720527" TEXT="also brauche ich einen /dev/null-Mutator">
-<icon BUILTIN="flag-yellow"/>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294727470" ID="ID_1958316881" MODIFIED="1539294738485" TEXT="speziellen Binding-Layer fabrizieren">
-<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294698801" ID="ID_1533611583" MODIFIED="1539299026168" TEXT="also brauche ich einen /dev/null-Mutator">
+<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1539294727470" ID="ID_1958316881" MODIFIED="1539299017213" TEXT="speziellen Binding-Layer fabrizieren">
+<icon BUILTIN="button_ok"/>
 <node CREATED="1539294807066" ID="ID_1137741867" MODIFIED="1539294809654" TEXT="wie?"/>
 <node CREATED="1539294812306" ID="ID_1564927840" MODIFIED="1539294826763" TEXT="mu&#xdf; das Standard-Mapping anschauen"/>
 <node CREATED="1539294846845" ID="ID_1839295475" MODIFIED="1539294935855" TEXT="TreeDiffMutatorBinding">
@@ -16596,8 +16596,8 @@
 <node CREATED="1539294909749" ID="ID_1965063755" MODIFIED="1539294918319" TEXT="Impl in tree-diff.cpp">
 <icon BUILTIN="idea"/>
 </node>
-<node BACKGROUND_COLOR="#fdfdcf" COLOR="#ff0000" CREATED="1539294950567" ID="ID_1321971857" MODIFIED="1539294956088" TEXT="alle F&#xe4;lle durchklappern">
-<icon BUILTIN="flag-pink"/>
+<node COLOR="#338800" CREATED="1539294950567" ID="ID_1321971857" MODIFIED="1539298935822" TEXT="alle F&#xe4;lle durchklappern">
+<icon BUILTIN="button_ok"/>
 </node>
 </node>
 </node>
@@ -16606,6 +16606,15 @@
 </node>
 <node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539294760464" ID="ID_1376112641" MODIFIED="1539294792408" TEXT="DiffIgnoreChanges_test">
 <icon BUILTIN="flag-yellow"/>
+<node COLOR="#338800" CREATED="1539298953819" ID="ID_1706428916" MODIFIED="1539298972769" TEXT="leerer TreeMutator produziert Fehler">
+<icon BUILTIN="button_ok"/>
+</node>
+<node COLOR="#338800" CREATED="1539298974312" ID="ID_986781359" MODIFIED="1539298992271" TEXT="BlackHoleMutation fri&#xdf;t alles">
+<icon BUILTIN="button_ok"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1539298993222" ID="ID_647799125" MODIFIED="1539299007509" TEXT="Kombinieren mit speziellem Overlay">
+<icon BUILTIN="flag-yellow"/>
+</node>
 </node>
 </node>
 </node>