Library: generic model transformer to get accepted string

The `bindMatch()` as implemented yesterday works only directly on top
of the terminal parsers, which yield a `RegExp`-Matcher. However,
it would be desirable to provide a generic shortcut to always get
some string as result model. A simple fallback is to return
the part of the input-string accepted thus far.

src/lib/parse.hpp

@@ -41,6 +41,7 @@
 #include "lib/meta/function.hpp"
 #include "lib/meta/trait.hpp"
 #include "lib/regex.hpp"
+#include "lib/test/diagnostic-output.hpp"/////////TODO
 
 #include <optional>
 #include <utility>
@@ -204,12 +205,50 @@ namespace util {
                       {
                         auto eval = origConnex.parse (toParse);
                         if (eval.result)
-                          return {binding (move (*eval.result))};
+                          return {binding (move (*eval.result))
+                                 ,eval.consumed};
                         else
                           return {std::nullopt};
                       }};
     }
     
+    template<class CON>
+    auto
+    toStringConnex (CON&& connex, uint part)
+    {
+      using Result = typename CON::Result;
+      using Arg = std::add_rvalue_reference_t<Result>;
+      return Connex([baseConnex = forward<CON>(connex)
+                    ,part
+                    ]
+                    (StrView toParse) -> Eval<string>
+                      {
+                        if constexpr (lib::meta::is_basically<Result,smatch>())
+                          {
+                            Eval<smatch> eval = baseConnex.parse (toParse);
+                            if (eval.result)
+                              return {eval.result->str(part)
+                                     ,eval.consumed
+                                     };
+                            else
+                              return {std::nullopt};
+                          }
+                        else
+                          {
+                            auto eval = baseConnex.parse (toParse);
+                            if (eval.result)
+                              {
+                                size_t pre = leadingWhitespace (toParse);
+                                return {string{toParse.substr (pre, eval.consumed)}
+                                       ,eval.consumed
+                                       };
+                              }
+                            else
+                              return {std::nullopt};
+                          }
+                      });
+    }
+    
     
     
     /* ===== building structured models ===== */
@@ -1008,10 +1047,8 @@ namespace util {
     auto
     Syntax<PAR>::bindMatch (uint group)
       {
-        return bind ([group](smatch const& mat)
+        return accept(
-                      {
+                 toStringConnex (move(parse_), group));
-                        return mat.str(group);
-                      });
       }
     
   }// namespace parse

tests/library/parse-test.cpp

@@ -569,19 +569,18 @@ namespace test {
       verify_modelBinding()
         {
           auto word{"\\w+"};
-          using Mod1 = SeqModel<smatch,smatch>;
+          auto syntax1 = accept(word).seq(word)                            // get a tuple with two RegExp-Matchers
-          auto syntax1 = accept(word).seq(word)
+                                       .bind([](SeqModel<smatch,smatch> res)
-                          .bind([](Mod1 res)
+                                               {
-                                  {
+                                                 return res.get<0>().str() +"-"+ res.get<1>().str();
-                                    return res.get<0>().str() +"-"+ res.get<1>().str();
+                                               });
-                                  });
           
           string s1{"ham actor"};
           CHECK (not syntax1.hasResult());
           syntax1.parse(s1);
           CHECK (syntax1.success());
           auto res1 = syntax1.getResult();
-          CHECK (showType<decltype(res1)>() == "string");                  // surprise! it is a simple string (as returned from λ)
+          CHECK (showType<decltype(res1)>() == "string");                  // surprise! it's a simple string (as returned from λ)
           CHECK (res1 == "ham-actor"_expect);
           
           // 💡 shortcut for RegExp match groups...
@@ -593,10 +592,17 @@ namespace test {
           
           auto wordEx = accept(word).bindMatch();
           auto syntax1c = accept(wordEx)
-                            .seq(wordEx)
+                            .seq(wordEx)                                   // sub-expressions did already transform to string
-                                        .bind([](SeqModel<string,string> m)
+                                       .bind([](SeqModel<string,string> res)
-                                                { return m.get<0>() +"-"+ m.get<1>(); });
+                                              { return res.get<0>() +"-"+ res.get<1>(); });
-SHOW_EXPR(syntax1c.parse(s1).getResult())
+          
+          CHECK (syntax1c.parse("ham  actor").getResult() == "ham-actor");
+          CHECK (syntax1c.parse("con artist").getResult() == "con-artist");
+          
+          auto syntax1d =accept(word).seq(word)
+                                       .bindMatch();                       // generic shortcut: ignore model, yield accepted part of input
+          CHECK (syntax1d.parse("ham  actor").getResult() == "ham  actor");
+          CHECK (syntax1d.parse(" ham actor").getResult() == "ham actor");
         }
     };
   

wiki/thinkPad.ichthyo.mm

@@ -57116,6 +57116,67 @@
 </html>
 </richcontent>
 <icon BUILTIN="pencil"/>
+<node CREATED="1737817661406" ID="ID_74788283" MODIFIED="1737817685150" TEXT="auf Matcher &#x27fc; match-group"/>
+<node CREATED="1737817685762" ID="ID_522207502" MODIFIED="1737817743080" TEXT="auf compound-Model &#x27fc; Teilkomponente">
+<node CREATED="1737818008232" ID="ID_1008681073" MODIFIED="1737818043982" TEXT="mu&#xdf; daf&#xfc;r constexpr-branch mit switch-on-Type machen"/>
+<node COLOR="#5b280f" CREATED="1737818191905" ID="ID_253639135" MODIFIED="1737818824310" TEXT="diese Verzweigung in der Builder-Methode machen">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      ...denn es steuert die Art der Dekoration
+    </p>
+  </body>
+</html>
+</richcontent>
+<icon BUILTIN="closed"/>
+<node CREATED="1737818825722" ID="ID_1135482924" MODIFIED="1737818869980" TEXT="geht nicht">
+<icon BUILTIN="stop-sign"/>
+</node>
+<node BACKGROUND_COLOR="#e0ceaa" COLOR="#690f14" CREATED="1737818829210" ID="ID_1026366531" MODIFIED="1737818865413" TEXT="Ergebnis &#x3bb;-typed">
+<icon BUILTIN="messagebox_warning"/>
+</node>
+</node>
+<node BACKGROUND_COLOR="#e0ceaa" COLOR="#690f14" CREATED="1737818884938" ID="ID_580741187" MODIFIED="1737820168826" TEXT="wegen dem &#xbb;insgesamt abgedeckten String&#xab;  &#x27f9; nicht per bind() realisierbar">
+<linktarget COLOR="#d21839" DESTINATION="ID_580741187" ENDARROW="Default" ENDINCLINATION="-152;6;" ID="Arrow_ID_1339747714" SOURCE="ID_1259641042" STARTARROW="None" STARTINCLINATION="21;-32;"/>
+<icon BUILTIN="clanbomber"/>
+</node>
+<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1737818936319" ID="ID_1719662007" MODIFIED="1737820213249" TEXT="mu&#xdf; also speziellen Connex erzeugen">
+<icon BUILTIN="pencil"/>
+<node COLOR="#435e98" CREATED="1737819592756" ID="ID_634105899" MODIFIED="1737820210832" TEXT="dann auch besser als toStringConnex ">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      analog wie die anderen Combinatoren und buildConnex()
+    </p>
+  </body>
+</html>
+</richcontent>
+</node>
+<node COLOR="#338800" CREATED="1737820217112" ID="ID_983053078" MODIFIED="1737820261322" TEXT="da kommt dann die constexpr-if-Kaskade rein">
+<icon BUILTIN="button_ok"/>
+</node>
+<node BACKGROUND_COLOR="#fdfdcf" COLOR="#ff0000" CREATED="1737820230519" ID="ID_4755618" MODIFIED="1737820256010" TEXT="repetitiever Code &#x27f9; vereinfachen">
+<icon BUILTIN="flag-pink"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1737820266129" ID="ID_1685629820" MODIFIED="1737820275519" TEXT="brauche Traits zum Erkennen der Modell-F&#xe4;lle">
+<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#f8f1cb" COLOR="#a50125" CREATED="1737820277891" ID="ID_1704538350" MODIFIED="1737820288067" TEXT="Problem: es sind variadic-templates">
+<icon BUILTIN="messagebox_warning"/>
+</node>
+</node>
+</node>
+</node>
+<node CREATED="1737817759473" ID="ID_1259641042" MODIFIED="1737820162400" TEXT="0 &#x27fc; insgesamt abgedeckten String">
+<arrowlink COLOR="#d21839" DESTINATION="ID_580741187" ENDARROW="Default" ENDINCLINATION="-152;6;" ID="Arrow_ID_1339747714" STARTARROW="None" STARTINCLINATION="21;-32;"/>
+<node CREATED="1737818264773" ID="ID_120023356" MODIFIED="1737818272264" TEXT="genereller fall-Back"/>
+<node CREATED="1737818273492" ID="ID_1978233039" MODIFIED="1737818392552" TEXT="damit fehlertolerant"/>
+</node>
 </node>
 </node>
 <node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1737509793049" ID="ID_1532451583" MODIFIED="1737763426814" TEXT="komplexere F&#xe4;lle testen">
@@ -57128,10 +57189,35 @@
 <icon BUILTIN="messagebox_warning"/>
 <node CREATED="1737768409191" ID="ID_46123353" MODIFIED="1737768426237" TEXT="&#x3bb;-generic funktionieren nicht wie gew&#xfc;nscht"/>
 <node CREATED="1737768426892" ID="ID_1722753025" MODIFIED="1737768440774" TEXT="und sonst mu&#xdf; man immer die Model-Namen ganz anschreiben"/>
+<node CREATED="1737817647567" ID="ID_1641437634" MODIFIED="1737817658826" TEXT="bindMatch() k&#xf6;nnte noch mehr tun"/>
 </node>
-<node BACKGROUND_COLOR="#fafe99" COLOR="#fa002a" CREATED="1737776743702" ID="ID_1501521982" MODIFIED="1737776790953" TEXT="sonderbares Verhalten mit zwe sub-Syntax-Klauseln und Binder">
+<node COLOR="#435e98" CREATED="1737776743702" ID="ID_1501521982" MODIFIED="1737817618502" TEXT="sonderbares Verhalten mit zwe sub-Syntax-Klauseln und Binder">
 <icon BUILTIN="broken-line"/>
 <node CREATED="1737776795928" ID="ID_935270717" MODIFIED="1737776813345" TEXT="es kommt zweimal der bind-match vom ersten Wort"/>
+<node CREATED="1737817572295" ID="ID_1167831095" MODIFIED="1737817616236">
+<richcontent TYPE="NODE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      ganz banal: habe <font face="Monospaced">eval.consumed</font>&#160;nicht weitergegeben
+    </p>
+  </body>
+</html>
+</richcontent>
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      d.h. jede sub-expression setzt wieder am Anfang auf
+    </p>
+  </body>
+</html>
+</richcontent>
+</node>
 </node>
 </node>
 </node>