LUMIERA.clone/tests/core/steam/control/command-equality-test.cpp
Ichthyostega 20392eee1c clean-up: successfully replaced the old fixed type sequence (closes: #987)
This resolves an intricate problem related to metaprogramming with
variadic templates and function signatures. Due to exceptional complexity,
a direct solution was blocked for several years, and required a better
organisation of the support code involved; several workarounds were
developed, gradually leading to a transition path, which could now
be completed in an focused clean-up effort over the last week.

Metaprogramming with sequences of types is organised into three layers:
- simple tasks can be solved with the standard facilities of the language,
  using pattern match with variadic template specialisations
- the ''type-sequence'' construct `Types<T...>` takes the centre stage
  for the explicit definition of collections of types; it can be re-bound
  to other variadic templates and supports simple direct manipulation
- for more elaborate and advanced processing tasks, a ''Loki-style type list''
  can be obtained from a type-sequence, allowing to perform recursive
  list processing task with a technique similar to LISP.
2025-06-07 18:04:59 +02:00

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/*
CommandEquality(Test) - verify equality comparisons on command's subsystems
Copyright (C)
2009, 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 command-equality-test.cpp
** unit test \ref CommandEquality_test
*/
#include "lib/test/run.hpp"
#include "lib/test/test-helper.hpp"
#include "steam/control/command-def.hpp"
#include "steam/control/command-mutation.hpp"
#include "steam/control/argument-erasure.hpp"
#include "steam/control/command-storage-holder.hpp"
#include "steam/control/command-simple-closure.hpp"
#include "steam/control/memento-tie.hpp"
#include "lib/meta/tuple-helper.hpp"
#include "lib/format-cout.hpp"
#include "lib/symbol.hpp"
#include "lib/util.hpp"
#include <functional>
#include <string>
#include <tuple>
namespace steam {
namespace control {
namespace test {
using namespace lib::meta;
using lib::Symbol;
using util::isnil;
using util::isSameObject;
using std::function;
using std::bind;
using std::string;
using std::make_tuple;
namespace {
string check_;
Symbol COMMAND1 ("test.equalityCommand1");
Symbol COMMAND2 ("test.equalityCommand2");
const string MARK_1 ("|_1_");
const string MARK_2 ("|_2_");
void oper_1 (char par) { check_ += MARK_1 + par; }
void oper_2 (char par) { check_ += MARK_2 + par; }
string capt_1 (char par) { return check_ + MARK_1 + "|"+par+"|"; }
string capt_2 (char par) { return check_ + MARK_2 + "|"+par+"|"; }
void undo_1 (char par, string mem) { check_ = mem + MARK_1 + par + "|";}
void undo_2 (char par, string mem) { check_ = mem + MARK_2 + par + "|";}
typedef void Sig_oper(char);
typedef string Sig_capt(char);
typedef void Sig_undo(char,string);
typedef function<Sig_oper> Fun_o;
typedef function<Sig_capt> Fun_c;
typedef function<Sig_undo> Fun_u;
using ArgTuple = std::tuple<char>;
using ArgHolder = OpClosure<Sig_oper>;
using MemHolder = MementoTie<Sig_oper, string>;
using Closure = SimpleClosure<Sig_oper>;
}
/*************************************************************************************//**
* @test cover command equality detection.
* Two commands are deemed equivalent, if they are based on the same CommandImpl record.
* This means, we only rely on the _identity_ of those commands, but do not check the
* _equivalence_ of their backing implementations. The latter can not be possibly
* implemented in a totally airtight fashion, and for this reason, the C++ standard
* decided not to support comparison between std::function objects.
*
* @see control::Command
* @see control::CommandImpl
* @see command-basic-test.hpp
*/
class CommandEquality_test : public Test
{
virtual void
run (Arg)
{
CHECK (&oper_1 != &oper_2);
CHECK (&capt_1 != &capt_2);
CHECK (&undo_1 != &undo_2);
CommandDef (COMMAND1)
.operation (oper_1)
.captureUndo (capt_1)
.undoOperation (undo_1)
;
CommandDef (COMMAND2)
.operation (oper_2)
.captureUndo (capt_2)
.undoOperation (undo_2)
;
Command c1 = Command::get(COMMAND1);
Command c2 = Command::get(COMMAND2);
CHECK (c1 == c1);
CHECK (c1 != c2);
CHECK (c2 != c1);
Command cx = c1;
CHECK (c1 == cx);
CHECK (cx == c1);
CHECK (!isSameObject (c1, c2));
// verify equality matches behaviour
string protocol1 = execCommand(c1);
string protocolX = execCommand(cx);
string protocol2 = execCommand(c2);
CHECK (protocol1 == protocolX);
CHECK (protocol1 != protocol2);
}
/** Helper: invoke and undo a command,
* @return resulting operation protocol
*/
string
execCommand (Command com)
{
check_ = "(start)";
com.bind('o');
com();
cout << com << ":" << check_ << endl;
com.undo();
cout << com << ":" << check_ << endl;
return check_;
}
};
/** Register this test class... */
LAUNCHER (CommandEquality_test, "function controller");
}}} // namespace steam::control::test