Remove C++ subgame-perfect equilibrium solver (#641)

* Remove C++ solve-by-subgames implementation.

This removes the subgame-perfect equilibrium solver
in C++ and from the associated command-line
tools for `enumpure`, `lp`, and `lcp`.

This will be replace in due course with a more flexible
and customisable functionality.

Closes #637.

Author: tturocy

ChangeLog

@@ -17,6 +17,9 @@
 ### Removed
 - Eliminating dominated actions has been removed from the GUI as it was implementing a non-standard
   formulation of dominance.  (#612)
+- The C++ method for computing subgame perfect equilibria with selected methods has been removed
+  (and as a result from the `enumpure`, `lp`, and `lcp` command-line tools); this will be replaced
+  with new and more customisable approaches. (#639)
 
 ## [16.4.1] - unreleased
 

Makefile.am

@@ -309,7 +309,6 @@ game_SOURCES = \
 	src/games/stratpure.cc \
 	src/games/stratpure.h \
 	src/games/stratmixed.h \
-	src/games/nash.cc \
 	src/games/file.cc \
 	src/games/writer.cc \
 	src/games/writer.h \

doc/tools.enumpure.rst

@@ -43,14 +43,6 @@ pure-strategy Nash equilibria.
    extensive games, as strategic games have only one information set
    per player.
 
-.. cmdoption:: -P
-
-   By default, the program computes all pure-strategy Nash
-   equilibria in an extensive game. This switch instructs the program to
-   find only pure-strategy Nash equilibria which are subgame perfect.
-   (This has no effect for strategic games, since there are no proper
-   subgames of a strategic game.)
-
 .. cmdoption:: -h
 
    Prints a help message listing the available options.

doc/tools.lcp.rst

@@ -51,13 +51,6 @@ game.
    causes the program to output greater detail on each equilbrium
    profile computed.
 
-.. cmdoption:: -P
-
-   By default, the program computes Nash equilibria in an extensive
-   game. This switch instructs the program to find only equilibria
-   which are subgame perfect.  (This has no effect for strategic
-   games, since there are no proper subgames of a strategic game.)
-
 .. cmdoption:: -e EQA
 
    By default, the program will find all equilibria accessible from

doc/tools.lp.rst

@@ -44,13 +44,6 @@ points of that set.
    causes the program to output greater detail on each equilbrium
    profile computed.
 
-.. cmdoption:: -P
-
-   By default, the program computes Nash equilibria in an extensive
-   game. This switch instructs the program to find only equilibria
-   which are subgame perfect.  (This has no effect for strategic
-   games, since there are no proper subgames of a strategic game.)
-
 .. cmdoption:: -h
 
    Prints a help message listing the available options.

src/games/nash.cc

@@ -60,10 +60,6 @@ ToMixedBehaviorProfile(const std::list<MixedStrategyProfile<T>> &p_list)
 template <class T>
 using BehaviorSolverType = std::function<std::list<MixedBehaviorProfile<T>>(const Game &)>;
 
-template <class T>
-std::list<MixedBehaviorProfile<T>> SolveBySubgames(const Game &, BehaviorSolverType<T> p_solver,
-                                                   BehaviorCallbackType<T> p_onEquilibrium);
-
 //
 // Exception raised when maximum number of equilibria to compute
 // has been reached.  A convenience for unraveling a potentially

src/games/nash.h

@@ -22,12 +22,13 @@
 
 #include <iostream>
 #include <fstream>
-#include <cstdlib>
 #include <getopt.h>
 
 #include "gambit.h"
 #include "games/writer.h"
 
+using namespace Gambit;
+
 void PrintBanner(std::ostream &p_stream)
 {
   p_stream << "Convert games among various file formats\n";
@@ -79,7 +80,7 @@ int main(int argc, char *argv[])
       break;
     case '?':
       if (isprint(optopt)) {
-        std::cerr << argv[0] << ": Unknown option `-" << ((char)optopt) << "'.\n";
+        std::cerr << argv[0] << ": Unknown option `-" << static_cast<char>(optopt) << "'.\n";
       }
       else {
         std::cerr << argv[0] << ": Unknown option character `\\x" << optopt << "`.\n";
@@ -122,7 +123,7 @@ int main(int argc, char *argv[])
   }
 
   try {
-    const Gambit::Game game = Gambit::ReadGame(*input_stream);
+    const Game game = ReadGame(*input_stream);
 
     if (rowPlayer < 1 || rowPlayer > static_cast<int>(game->NumPlayers())) {
       std::cerr << argv[0] << ": Player " << rowPlayer << " does not exist.\n";

src/tools/convert/convert.cc

@@ -20,7 +20,6 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 //
 
-#include <cstdlib>
 #include <getopt.h>
 #include <iostream>
 #include <fstream>
@@ -34,7 +33,7 @@ using namespace Gambit::Nash;
 
 template <class T>
 void PrintCliques(const List<List<MixedStrategyProfile<T>>> &p_cliques,
-                  std::shared_ptr<StrategyProfileRenderer<T>> p_renderer)
+                  std::shared_ptr<MixedProfileRenderer<T>> p_renderer)
 {
   for (size_t cl = 1; cl <= p_cliques.size(); cl++) {
     for (size_t i = 1; i <= p_cliques[cl].size(); i++) {
@@ -75,7 +74,7 @@ int main(int argc, char *argv[])
   int numDecimals = 6;
 
   int long_opt_index = 0;
-  struct option long_options[] = {
+  option long_options[] = {
       {"help", 0, nullptr, 'h'}, {"version", 0, nullptr, 'v'}, {nullptr, 0, nullptr, 0}};
   while ((c = getopt_long(argc, argv, "d:vhqcS", long_options, &long_opt_index)) != -1) {
     switch (c) {
@@ -99,7 +98,7 @@ int main(int argc, char *argv[])
       break;
     case '?':
       if (isprint(optopt)) {
-        std::cerr << argv[0] << ": Unknown option `-" << ((char)optopt) << "'.\n";
+        std::cerr << argv[0] << ": Unknown option `-" << static_cast<char>(optopt) << "'.\n";
       }
       else {
         std::cerr << argv[0] << ": Unknown option character `\\x" << optopt << "`.\n";
@@ -130,8 +129,7 @@ int main(int argc, char *argv[])
   try {
     const Game game = ReadGame(*input_stream);
     if (useFloat) {
-      std::shared_ptr<StrategyProfileRenderer<double>> renderer =
-          std::make_shared<MixedStrategyCSVRenderer<double>>(std::cout, numDecimals);
+      auto renderer = MakeMixedStrategyProfileRenderer<double>(std::cout, numDecimals, false);
       auto solution = EnumMixedStrategySolveDetailed<double>(
           game, [&](const MixedStrategyProfile<double> &p, const std::string &label) {
             renderer->Render(p, label);
@@ -141,8 +139,7 @@ int main(int argc, char *argv[])
       }
     }
     else {
-      std::shared_ptr<StrategyProfileRenderer<Rational>> renderer(
-          new MixedStrategyCSVRenderer<Rational>(std::cout));
+      auto renderer = MakeMixedStrategyProfileRenderer<Rational>(std::cout, numDecimals, false);
       auto solution = EnumMixedStrategySolveDetailed<Rational>(
           game, [&](const MixedStrategyProfile<Rational> &p, const std::string &label) {
             renderer->Render(p, label);