Merge remote-tracking branch 'origin/stable-2.0'

[bpt/guile.git] / libguile / procprop.c

diff --git a/libguile/procprop.c b/libguile/procprop.c
index 2ad941d..ff4648d 100644 (file)
--- a/libguile/procprop.c
+++ b/libguile/procprop.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1998,2000,2001,2003,2004, 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1998,2000,2001,2003,2004, 2006, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
  * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -43,9 +43,23 @@ SCM_GLOBAL_SYMBOL (scm_sym_name, "name");
 
 static SCM overrides;
 
+static SCM arity_overrides;
+
 int
 scm_i_procedure_arity (SCM proc, int *req, int *opt, int *rest)
 {
+  SCM o;
+
+  o = scm_weak_table_refq (arity_overrides, proc, SCM_BOOL_F);
+
+  if (scm_is_true (o))
+    {
+      *req = scm_to_int (scm_car (o));
+      *opt = scm_to_int (scm_cadr (o));
+      *rest = scm_is_true (scm_caddr (o));
+      return 1;
+    }
+
   while (!SCM_PROGRAM_P (proc))
     {
       if (SCM_STRUCTP (proc))
@@ -58,14 +72,40 @@ scm_i_procedure_arity (SCM proc, int *req, int *opt, int *rest)
         {
           if (!SCM_SMOB_APPLICABLE_P (proc))
             return 0;
-          proc = scm_i_smob_apply_trampoline (proc);
+          if (!scm_i_program_arity (SCM_SMOB_DESCRIPTOR (proc).apply_trampoline,
+                                    req, opt, rest))
+            return 0;
+
+          /* The trampoline gets the smob too, which users don't
+             see.  */
+          *req -= 1;
+
+          return 1;
         }
       else
         return 0;
     }
+
   return scm_i_program_arity (proc, req, opt, rest);
 }
 
+SCM_DEFINE (scm_set_procedure_minimum_arity_x, "set-procedure-minimum-arity!",
+            4, 0, 0, (SCM proc, SCM req, SCM opt, SCM rest),
+            "")
+#define FUNC_NAME s_scm_set_procedure_minimum_arity_x
+{
+  int t SCM_UNUSED;
+
+  SCM_VALIDATE_PROC (1, proc);
+  SCM_VALIDATE_INT_COPY (2, req, t);
+  SCM_VALIDATE_INT_COPY (3, opt, t);
+  SCM_VALIDATE_BOOL (4, rest);
+
+  scm_weak_table_putq_x (arity_overrides, proc, scm_list_3 (req, opt, rest));
+  return SCM_UNDEFINED;
+}
+#undef FUNC_NAME
+
 SCM_DEFINE (scm_procedure_minimum_arity, "procedure-minimum-arity", 1, 0, 0, 
            (SCM proc),
            "Return the \"minimum arity\" of a procedure.\n\n"
@@ -93,7 +133,7 @@ SCM_DEFINE (scm_procedure_minimum_arity, "procedure-minimum-arity", 1, 0, 0,
 
 SCM_DEFINE (scm_procedure_properties, "procedure-properties", 1, 0, 0, 
            (SCM proc),
-           "Return @var{obj}'s property list.")
+           "Return @var{proc}'s property list.")
 #define FUNC_NAME s_scm_procedure_properties
 {
   SCM ret;
@@ -171,6 +211,7 @@ void
 scm_init_procprop ()
 {
   overrides = scm_c_make_weak_table (0, SCM_WEAK_TABLE_KIND_KEY);
+  arity_overrides = scm_c_make_weak_table (0, SCM_WEAK_TABLE_KIND_KEY);
 #include "libguile/procprop.x"
 }