Imported Upstream version 2.19.45

[lilypond.git] / lily / include / lily-modules.hh

diff --git a/lily/include/lily-modules.hh b/lily/include/lily-modules.hh
new file mode 100644 (file)
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--- /dev/null
+++ b/lily/include/lily-modules.hh
@@ -0,0 +1,99 @@
+/*
+  This file is part of LilyPond, the GNU music typesetter.
+
+  Copyright (C) 2015 by David Kastrup <dak@gnu.org>
+
+  LilyPond 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 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond 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 LilyPond.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef LILY_MODULES_HH
+#define LILY_MODULES_HH
+
+#include "lily-guile.hh"
+
+class Scm_variable;
+
+class Scm_module
+{
+  const char *name_;
+  SCM module_;
+  class Variable_record;
+  Variable_record *variables_;
+  static void boot_init (void *);
+public:
+  void boot (void (*init)() = 0);
+  void import ();
+  void register_variable (const char *name, Scm_variable *var);
+
+  Scm_module (const char *name);
+
+  operator SCM ()
+  {
+    assert (SCM_MODULEP (module_));
+    return module_;
+  }
+};
+
+class Scm_variable
+{
+  SCM var_;
+  friend Scm_module;
+  void boot (const char *name);
+  void import (SCM module, const char *name);
+public:
+  operator SCM & ()
+  {
+#if 0
+    // One could conceivably work with variables even before the
+    // module is initialized
+    return SCM_VARIABLEP (var_) ? *SCM_VARIABLE_LOC (var_) : var_;
+#endif
+#if DEBUG
+    assert (SCM_VARIABLEP (var_));
+#endif
+    return *SCM_VARIABLE_LOC (var_);
+  }
+  SCM operator () ()
+  {
+    return scm_call_0 (*this);
+  }
+  SCM operator () (SCM arg1)
+  {
+    return scm_call_1 (*this, arg1);
+  }
+  SCM operator () (SCM arg1, SCM arg2)
+  {
+    return scm_call_2 (*this, arg1, arg2);
+  }
+  SCM operator () (SCM arg1, SCM arg2, SCM arg3)
+  {
+    return scm_call_3 (*this, arg1, arg2, arg3);
+  }
+  SCM operator () (SCM arg1, SCM arg2, SCM arg3, SCM arg4)
+  {
+    return scm_call_4 (*this, arg1, arg2, arg3, arg4);
+  }
+  Scm_variable (Scm_module &m, const char *name, SCM value = SCM_UNDEFINED);
+};
+
+template <Scm_module &m>
+class Module_variable : public Scm_variable
+{
+public:
+  Module_variable (const char *name, SCM value = SCM_UNDEFINED)
+    : Scm_variable (m, name, value)
+  { }
+};
+
+#endif