Make 'join' accept more than 2 arguments.

Author: Kasper Peeters

core/algorithms/substitute.cc

@@ -19,8 +19,8 @@ substitute::substitute(const Kernel& k, Ex& tr, Ex& args_, bool partial)
 	if(args.is_empty()) 
 		throw ArgumentException("substitute: Replacement rule is an empty expression.");
 
-	Stopwatch sw;
-	sw.start();
+	// Stopwatch sw;
+	// sw.start();
 	cadabra::do_list(args, args.begin(), [&](Ex::iterator arrow) {
 		//args.print_recursive_treeform(std::cerr, arrow);
 		if(*arrow->name!="\\arrow" && *arrow->name!="\\equals")
@@ -83,8 +83,8 @@ substitute::substitute(const Kernel& k, Ex& tr, Ex& args_, bool partial)
 			}
 		return true;
 		});
-	sw.stop();
-	std::cerr << "preparation took " << sw << std::endl;
+	// sw.stop();
+	// std::cerr << "preparation took " << sw << std::endl;
 	}
 
 bool substitute::can_apply(iterator st)

core/pythoncdb/py_ex.cc

@@ -97,6 +97,7 @@ namespace cadabra {
 
    Ex_ptr Ex_join(const Ex_ptr ex1, const Ex_ptr ex2)
 		{
+		// DEPRECATED: no longer in use, can be removed
 		if (ex1->size() == 0) return ex2;
 		if (ex2->size() == 0) return ex1;
 
@@ -130,6 +131,18 @@ namespace cadabra {
 			return ret;
 			}
 		}
+
+   Ex_ptr Ex_join(std::vector<Ex_ptr> exs)
+		{
+		auto ret = std::make_shared<Ex>("\\comma");
+
+		for(const Ex_ptr& ex: exs) {
+			auto loc = ret->append_child(ret->begin(), ex->begin());
+			if(*ex->begin()->name=="\\comma") 
+				ret->flatten_and_erase(loc);
+			}
+		return ret;
+		}
 
 	Ex_ptr Ex_mul(const Ex_ptr ex1, const Ex_ptr ex2)
 		{
@@ -689,7 +702,14 @@ namespace cadabra {
 		.def("from_sympy", &sympy::SympyBridge::import_ex)
 		;
 
-		m.def("join", &Ex_join);
+		m.def("join", [](const Ex_ptr ex1, const Ex_ptr ex2, py::args args) {
+			std::vector<Ex_ptr> ex = {ex1, ex2};
+        	for (const auto& arg : args) {
+				ex.push_back(arg.cast<Ex_ptr>());
+				}
+        	return Ex_join(ex);
+    		});
+
 		m.def("tree", &print_tree);
 
 		m.def("map_sympy", &map_sympy_wrapper,

tests/programming.cdb

@@ -321,6 +321,18 @@ def test14():
     ex3 = join(ex1, ex2)
     assert(ex3==${A,C}$)
     print("Test 14e passed")
+    ex1:= {A,B};
+    ex2:= C;
+    ex3:= {D, E};
+    ex4= join(ex1, ex2, ex3)
+    assert(ex4==${A,B,C,D,E}$)
+    print("Test 14f passed")
+    ex1:= A;
+    ex2:= C;
+    ex3:= {D, E};
+    ex4= join(ex1, ex2, ex3)
+    assert(ex4==${A,C,D,E}$)
+    print("Test 14g passed")
 
 test14()