Restructure rule classes.

Classes under "rulesets" have been moved to "rules", and split up into
futher subdirectories matching their library. As a result we can now
better separate the python bindings, so that things that belongs to the
simulation are separeted from things that belongs to the ai.

rules/python/PythonContext.cpp

@@ -0,0 +1,106 @@
+// Cyphesis Online RPG Server and AI Engine
+// Copyright (C) 2009 Alistair Riddoch
+//
+// This program 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.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software Foundation,
+// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+
+#include <Python.h>
+#include <Python-ast.h>
+
+#include "PythonContext.h"
+
+#include "common/log.h"
+
+PythonContext::PythonContext()
+{
+    m_module = PyImport_AddModule("__main__");
+    if (m_module == nullptr) {
+        log(ERROR, "Could not import __main__");
+        return;
+    }
+    m_globals = PyModule_GetDict(m_module);
+    m_locals = PyDict_New();
+    m_arena = PyArena_New();
+}
+
+PythonContext::~PythonContext()
+{
+    PyArena_Free(m_arena);
+    //PyObject_Free(m_locals);
+    //PyObject_Free(m_module);
+
+}
+
+static PyObject *
+run_mod(mod_ty mod, const char *filename, PyObject *globals, PyObject *locals,
+         PyCompilerFlags *flags, PyArena *arena)
+{
+    PyCodeObject *co;
+    PyObject *v;
+    co = PyAST_Compile(mod, filename, flags, arena);
+    if (co == nullptr)
+        return nullptr;
+    v = PyEval_EvalCode((PyObject*)co, globals, locals);
+    Py_DECREF(co);
+    return v;
+}
+
+std::string PythonContext::runCommand(const std::string & s)
+{
+    // This is expanded from PyRun_SimpleString in the Python library
+    // so that we can report errors better at the parsing stage
+    PyObject *ret = nullptr;
+    mod_ty mod;
+
+    mod = PyParser_ASTFromString(s.c_str(),
+                                 "<string>",
+                                 Py_single_input,
+                                 nullptr,
+                                 m_arena);
+    if (mod == nullptr) {
+        PyErr_Print();
+        return "[parseerror]";
+    }
+    ret = run_mod(mod, "<string>", m_globals, m_locals, nullptr, m_arena);
+    if (ret == nullptr) {
+        PyErr_Print();
+        return "ERROR";
+    }
+    PyObject * repr = PyObject_Repr(ret);
+    if (repr == 0) {
+        return "[undecodable]";
+    }
+    return PyUnicode_AsUTF8(repr);
+
+#if 0
+    PyObject * res = PyRun_String(s.c_str(),
+                                  Py_single_input,
+                                  m_globals,
+                                  m_locals);
+    if (res == 0) {
+        if (PyErr_Occurred() == 0) {
+            return "WHAT";
+        } else {
+            PyErr_Print();
+            return "ERROR";
+        }
+    }
+    PyObject * repr = PyObject_Repr(res);
+    if (repr == 0) {
+        return "[undecodable]";
+    }
+    return PyUnicode_AsUTF8(repr);
+#endif
+}