X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Funpure-pure-container.cc;h=ede75022c6d0c148857e19f01f22f1c2687138c5;hb=47db9a3883d726ca53e2133a3b2298f78dd6a32e;hp=9a8639dad09b718db0efcf2c926aeecaa057a175;hpb=f875ef39c544bd3499dae5360e9e24f69933575f;p=lilypond.git

diff --git a/lily/unpure-pure-container.cc b/lily/unpure-pure-container.cc
index 9a8639dad0..ede75022c6 100644
--- a/lily/unpure-pure-container.cc
+++ b/lily/unpure-pure-container.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2011 Mike Solomon <mike@apollinemike.com>
+  Copyright (C) 2011--2015 Mike Solomon <mike@mikesolomon.org>
 
 
   LilyPond is free software: you can redistribute it and/or modify
@@ -21,90 +21,68 @@
 
 #include "grob.hh"
 
-static scm_t_bits unpure_pure_container_tag;
-
-bool
-is_unpure_pure_container (SCM s)
-{
-  return (SCM_NIMP (s) && SCM_CELL_TYPE (s) == unpure_pure_container_tag);
-}
-
-SCM
-unpure_pure_container_unpure_part (SCM smob)
+// Reroutes a call to the contained function after dropping last two
+// arguments.  Used for applying an "unpure" function in a "pure"
+// context.
+class Unpure_pure_call : public Smob1<Unpure_pure_call>
 {
-  LY_ASSERT_TYPE (is_unpure_pure_container, smob, 1);
-  return (SCM) SCM_CELL_WORD_1 (smob);
-}
+public:
+  LY_DECLARE_SMOB_PROC (2, 0, 1, (SCM self, SCM arg1, SCM arg2, SCM rest))
+  {
+    return scm_apply_0 (Unpure_pure_call::unsmob (self)->scm1 (),
+                        scm_call_2 (ly_lily_module_constant ("drop-right"),
+                                    scm_cons2 (arg1, arg2, rest),
+                                    scm_from_int (2)));
+  }
+};
 
 SCM
-unpure_pure_container_pure_part (SCM smob)
+Unpure_pure_container::pure_part () const
 {
-  LY_ASSERT_TYPE (is_unpure_pure_container, smob, 1);
-  return (SCM) SCM_CELL_WORD_2 (smob);
+  return SCM_UNBNDP (scm2 ())
+    ? Unpure_pure_call::make_smob (scm1 ())
+    : scm2 ();
 }
 
-LY_DEFINE (ly_unpure_pure_container_p, "ly:unpure-pure-container?",
-           1, 0, 0, (SCM clos),
-           "Is @var{clos} an unpure pure container?")
-{
-  return scm_from_bool (is_unpure_pure_container (clos));
-}
+const char Unpure_pure_container::type_p_name_[] = "ly:unpure-pure-container?";
 
 LY_DEFINE (ly_make_unpure_pure_container, "ly:make-unpure-pure-container",
            1, 1, 0, (SCM unpure, SCM pure),
            "Make an unpure-pure container.  @var{unpure} should be an unpure"
-           " expression, and @var{pure} should be a pure expression. If @var{pure}"
-           " is ommitted, the value of @var{unpure} will be used twice.")
+           " expression, and @var{pure} should be a pure expression.  If @var{pure}"
+           " is omitted, the value of @var{unpure} will be used twice,"
+           " except that a callback is given two extra arguments"
+           " that are ignored for the sake of pure calculations.")
 {
-  SCM z;
-
-  if (pure == SCM_UNDEFINED)
-    pure = unpure;
-
-  SCM_NEWSMOB2 (z, unpure_pure_container_tag, SCM_UNPACK (unpure), SCM_UNPACK (pure));
-  return z;
+  return Unpure_pure_container::make_smob (unpure, pure);
 }
 
 LY_DEFINE (ly_unpure_pure_container_unpure_part, "ly:unpure-pure-container-unpure-part",
            1, 0, 0, (SCM pc),
            "Return the unpure part of @var{pc}.")
 {
-  LY_ASSERT_TYPE (is_unpure_pure_container, pc, 1);
-  return unpure_pure_container_unpure_part (pc);
+  LY_ASSERT_SMOB (Unpure_pure_container, pc, 1);
+  return Unpure_pure_container::unsmob (pc)->unpure_part ();
 }
 
 LY_DEFINE (ly_unpure_pure_container_pure_part, "ly:unpure-pure-container-pure-part",
            1, 0, 0, (SCM pc),
            "Return the pure part of @var{pc}.")
 {
-  LY_ASSERT_TYPE (is_unpure_pure_container, pc, 1);
-  return unpure_pure_container_pure_part (pc);
+  LY_ASSERT_SMOB (Unpure_pure_container, pc, 1);
+  return Unpure_pure_container::unsmob (pc)->pure_part ();
 }
 
 int
-print_unpure_pure_container (SCM s, SCM port, scm_print_state *)
+Unpure_pure_container::print_smob (SCM port, scm_print_state *)
 {
   scm_puts ("#<unpure-pure-container ", port);
-  scm_display (unpure_pure_container_unpure_part (s), port);
-  scm_puts (" ", port);
-  scm_display (unpure_pure_container_pure_part (s), port);
+  scm_display (unpure_part (), port);
+  if (!is_unchanging ())
+    {
+      scm_puts (" ", port);
+      scm_display (pure_part (), port);
+    }
   scm_puts (" >", port);
   return 1;
 }
-
-SCM
-pure_mark (SCM pure)
-{
-  scm_gc_mark (unpure_pure_container_unpure_part (pure));
-  scm_gc_mark (unpure_pure_container_pure_part (pure));
-  return pure;
-}
-
-void init_unpure_pure_container ()
-{
-  unpure_pure_container_tag = scm_make_smob_type ("unpure-pure-container", 0);
-  scm_set_smob_mark (unpure_pure_container_tag, pure_mark);
-  scm_set_smob_print (unpure_pure_container_tag, print_unpure_pure_container);
-};
-
-ADD_SCM_INIT_FUNC (unpure_pure_container, init_unpure_pure_container);