* init.c (scm_boot_guile): Don't return the value of
[bpt/guile.git] / libguile / print.c
index 805f92c..adc7048 100644 (file)
@@ -51,6 +51,8 @@
 #include "read.h"
 #include "weaks.h"
 #include "unif.h"
+#include "alist.h"
+#include "struct.h"
 
 #include "print.h"
 \f
@@ -96,23 +98,18 @@ char *scm_isymnames[] =
   "#<unspecified>"
 };
 
-#ifdef DEBUG_EXTENSIONS
 scm_option scm_print_opts[] = {
-  { SCM_OPTION_BOOLEAN, "procnames", 0,
-    "Print names instead of closures." },
   { SCM_OPTION_SCM, "closure-hook", SCM_BOOL_F,
-    "Procedure used to print closures." }
+    "Hook for printing closures." },
+  { SCM_OPTION_BOOLEAN, "source", 0,
+    "Print closures with source." }
 };
 
 SCM_PROC (s_print_options, "print-options-interface", 0, 1, 0, scm_print_options);
-#ifdef __STDC__
-SCM
-scm_print_options (SCM setting)
-#else
+
 SCM
 scm_print_options (setting)
      SCM setting;
-#endif
 {
   SCM ans = scm_options (setting,
                         scm_print_opts,
@@ -120,93 +117,164 @@ scm_print_options (setting)
                         s_print_options);
   return ans;
 }
-#endif
 
 \f
 /* {Printing of Scheme Objects}
  */
 
 /* Detection of circular references.
+ *
+ * Due to other constraints in the implementation, this code has bad
+ * time complexity (O (depth * N)), The printer code will be
+ * completely rewritten before next release of Guile.  The new code
+ * will be O(N).
  */
-typedef struct ref_stack {
-  SCM vector;
-  SCM *top;
-  SCM *ceiling;
-  SCM *floor;
-} ref_stack;
-
-#define RESET_REF_STACK(stack) { stack.top = stack.floor; }
-#define PUSH_REF(stack, obj, label) \
+#define PUSH_REF(pstate, obj) \
 { \
-  register SCM *ref; \
-  for (ref = stack.floor; ref < stack.top; ++ref) \
-    if (*ref == (obj)) \
-      goto label; \
-  *stack.top++ = (obj); \
-  if (stack.top == stack.ceiling) \
-    grow_ref_stack (&stack); \
-} \
+  pstate->ref_stack[pstate->top++] = (obj); \
+  if (pstate->top == pstate->ceiling) \
+    grow_ref_stack (pstate); \
+}
 
-#define POP_REF(stack) { --stack.top; }
-#define SAVE_REF_STACK(stack, save) \
+#define ENTER_NESTED_DATA(pstate, obj, label) \
 { \
-  save = stack.floor - SCM_VELTS (stack.vector); \
-  stack.floor = stack.top; \
+  register int i; \
+  for (i = 0; i < pstate->top; ++i) \
+    if (pstate->ref_stack[i] == (obj)) \
+      goto label; \
+  if (pstate->fancyp) \
+    { \
+      if (pstate->top - pstate->list_offset >= pstate->level) \
+       { \
+         scm_gen_putc ('#', port); \
+         return; \
+       } \
+    } \
+  PUSH_REF(pstate, obj); \
 } \
 
-#define RESTORE_REF_STACK(stack, save) \
-{ stack.floor = SCM_VELTS (stack.vector) + save; }
+#define EXIT_NESTED_DATA(pstate) { --pstate->top; }
 
-#ifdef __STDC__
-static void
-init_ref_stack (ref_stack *stack)
-#else
-static void
-init_ref_stack (stack)
-     ref_stack *stack;
+static SCM print_state_pool;
+
+#if 1 /* Used for debugging purposes */
+SCM_PROC(s_current_pstate, "current-pstate", 0, 0, 0, scm_current_pstate);
+
+SCM
+scm_current_pstate ()
+{
+  return SCM_CADR (print_state_pool);
+}
 #endif
+
+#define PSTATE_SIZE 50L
+
+static SCM make_print_state SCM_P ((void));
+
+static SCM
+make_print_state ()
 {
-  stack->vector = scm_permanent_object (scm_make_vector (SCM_MAKINUM (30L),
-                                                        SCM_UNDEFINED,
-                                                        SCM_UNDEFINED));
-  stack->top = stack->floor = SCM_VELTS (stack->vector);
-  stack->ceiling = stack->floor + SCM_LENGTH (stack->vector);
+  SCM print_state = scm_make_struct (SCM_CAR (print_state_pool), /* pstate type */
+                                    SCM_INUM0,
+                                    SCM_EOL);
+  scm_print_state *pstate = SCM_PRINT_STATE (print_state);
+  pstate->ref_vect = scm_make_vector (SCM_MAKINUM (PSTATE_SIZE),
+                                     SCM_UNDEFINED,
+                                     SCM_UNDEFINED);
+  pstate->ref_stack = SCM_VELTS (pstate->ref_vect);
+  pstate->ceiling = SCM_LENGTH (pstate->ref_vect);
+  return print_state;
 }
 
-#ifdef __STDC__
-static void
-grow_ref_stack (ref_stack *stack)
-#else
+SCM
+scm_make_print_state ()
+{
+  SCM answer = 0;
+
+  /* First try to allocate a print state from the pool */
+  SCM_DEFER_INTS;
+  if (SCM_NNULLP (SCM_CDR (print_state_pool)))
+    {
+      answer = SCM_CADR (print_state_pool);
+      SCM_SETCDR (print_state_pool, SCM_CDDR (print_state_pool));
+    }
+  SCM_ALLOW_INTS;
+  
+  return answer ? answer : make_print_state ();
+}
+
+void
+scm_free_print_state (print_state)
+     SCM print_state;
+{
+  SCM handle;
+  scm_print_state *pstate = SCM_PRINT_STATE (print_state);
+  /* Cleanup before returning print state to pool.
+   * It is better to do it here.  Doing it in scm_prin1
+   * would cost more since that function is called much more
+   * often.
+   */
+  pstate->fancyp = 0;
+  SCM_NEWCELL (handle);
+  SCM_DEFER_INTS;
+  SCM_SETCAR (handle, print_state);
+  SCM_SETCDR (handle, SCM_CDR (print_state_pool));
+  SCM_SETCDR (print_state_pool, handle);
+  SCM_ALLOW_INTS;
+}
+
+static void grow_ref_stack SCM_P ((scm_print_state *pstate));
+
 static void
-grow_ref_stack (stack)
-     ref_stack *stack;
-#endif
+grow_ref_stack (pstate)
+     scm_print_state *pstate;
 {
-  int offset, new_size = 2 * SCM_LENGTH (stack->vector);
-  SCM *old_velts = SCM_VELTS (stack->vector);
-  scm_vector_set_length_x (stack->vector, SCM_MAKINUM (new_size));
-  offset = SCM_VELTS (stack->vector) - old_velts;
-  stack->top += offset;
-  stack->floor += offset;
-  stack->ceiling = SCM_VELTS (stack->vector) + new_size;
+  int new_size = 2 * pstate->ceiling;
+  scm_vector_set_length_x (pstate->ref_vect, SCM_MAKINUM (new_size));
+  pstate->ref_stack = SCM_VELTS (pstate->ref_vect);
+  pstate->ceiling = new_size;
 }
 
 
-/* Print generally.  Handles both write and display according to WRITING.
+static void print_circref SCM_P ((SCM port, scm_print_state *pstate, SCM ref));
+
+static void
+print_circref (port, pstate, ref)
+     SCM port;
+     scm_print_state *pstate;
+     SCM ref;
+{
+  register int i;
+  int self = pstate->top - 1;
+  i = pstate->top - 1;
+  if (SCM_CONSP (pstate->ref_stack[i]))
+    {
+      while (i > 0)
+       {
+         if (SCM_NCONSP (pstate->ref_stack[i - 1])
+             || SCM_CDR (pstate->ref_stack[i - 1]) != pstate->ref_stack[i])
+           break;
+         --i;
+       }
+      self = i;
+    }
+  for (i = pstate->top - 1; 1; --i)
+    if (pstate->ref_stack[i] == ref)
+      break;
+  scm_gen_putc ('#', port);
+  scm_intprint (i - self, 10, port);
+  scm_gen_putc ('#', port);
+}
+
+/* Print generally.  Handles both write and display according to PSTATE.
  */
 
-static ref_stack pstack;
 
-#ifdef __STDC__
 void 
-scm_iprin1 (SCM exp, SCM port, int writing)
-#else
-void 
-scm_iprin1 (exp, port, writing)
+scm_iprin1 (exp, port, pstate)
      SCM exp;
      SCM port;
-     int writing;
-#endif
+     scm_print_state *pstate;
 {
   register long i;
 taloop:
@@ -220,12 +288,12 @@ taloop:
       if (SCM_ICHRP (exp))
        {
          i = SCM_ICHR (exp);
-         scm_put_wchar (i, port, writing);
+         scm_put_wchar (i, port, SCM_WRITINGP (pstate));
 
        }
       else if (SCM_IFLAGP (exp)
               && (SCM_ISYMNUM (exp) < (sizeof scm_isymnames / sizeof (char *))))
-         scm_gen_puts (scm_regular_string, SCM_ISYMSCM_CHARS (exp), port);
+         scm_gen_puts (scm_regular_string, SCM_ISYMCHARS (exp), port);
       else if (SCM_ILOCP (exp))
        {
          scm_gen_puts (scm_regular_string, "#@", port);
@@ -260,67 +328,68 @@ taloop:
 
        case scm_tcs_cons_imcar:
        case scm_tcs_cons_nimcar:
-         PUSH_REF (pstack, exp, circref);
-         scm_iprlist ("(", exp, ')', port, writing);
-         POP_REF (pstack);
+         ENTER_NESTED_DATA (pstate, exp, circref);
+         scm_iprlist ("(", exp, ')', port, pstate);
+         EXIT_NESTED_DATA (pstate);
          break;
        circref:
-         scm_gen_write (scm_regular_string, "#<circ ref>", sizeof ("#<circ ref>") - 1, port);
+         print_circref (port, pstate, exp);
          break;
        case scm_tcs_closures:
-#ifdef DEBUG_EXTENSIONS
          if (SCM_NFALSEP (scm_procedure_p (SCM_PRINT_CLOSURE)))
            {
              SCM ans = scm_cons2 (exp, port,
-                                  scm_cons (writing ? SCM_BOOL_T : SCM_BOOL_F, SCM_EOL));
-             int save;
-             SAVE_REF_STACK (pstack, save);
+                                  scm_cons (SCM_WRITINGP (pstate)
+                                            ? SCM_BOOL_T
+                                            : SCM_BOOL_F,
+                                            SCM_EOL));
              ans = scm_apply (SCM_PRINT_CLOSURE, ans, SCM_EOL);
-             RESTORE_REF_STACK (pstack, save);
            }
-         else if (SCM_PRINT_PROCNAMES_P)
+         else
            {
-             SCM name;
+             SCM name, code;
              name = scm_procedure_property (exp, scm_i_name);
-             scm_gen_puts (scm_regular_string, "#<procedure", port);
-             if (SCM_NFALSEP (name))
+             code = SCM_CODE (exp);
+             scm_gen_puts (scm_regular_string, "#<procedure ", port);
+             if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
                {
+                 scm_gen_puts (scm_regular_string, SCM_ROCHARS (name), port);
                  scm_gen_putc (' ', port);
-                 /* FIXME */
-                 scm_gen_puts (scm_regular_string, SCM_CHARS (name), port);
                }
-             scm_gen_putc ('>', port);
-           }
-         else
-#endif
-           {
-             SCM code = SCM_CODE (exp);
-             exp = scm_unmemocopy (code,
-                                   SCM_EXTEND_SCM_ENV (SCM_CAR (code),
-                                                       SCM_EOL,
-                                                       SCM_ENV (exp)));
-             scm_iprlist ("#<CLOSURE ", exp, '>', port, writing);
+             scm_iprin1 (SCM_CAR (code), port, pstate);
+             if (SCM_PRINT_SOURCE_P)
+               {
+                 code = scm_unmemocopy (SCM_CDR (code),
+                                        SCM_EXTEND_ENV (SCM_CAR (code),
+                                                        SCM_EOL,
+                                                        SCM_ENV (exp)));
+                 ENTER_NESTED_DATA (pstate, exp, circref);
+                 scm_iprlist (" ", code, '>', port, pstate);
+                 EXIT_NESTED_DATA (pstate);
+               }
+             else
+               scm_gen_putc ('>', port);
            }
          break;
        case scm_tc7_mb_string:
        case scm_tc7_mb_substring:
-         scm_print_mb_string (exp, port, writing);
+         scm_print_mb_string (exp, port, SCM_WRITINGP (pstate));
          break;
        case scm_tc7_substring:
        case scm_tc7_string:
-         if (writing)
+         if (SCM_WRITINGP (pstate))
            {
-             scm_gen_putc ('\"', port);
+             scm_gen_putc ('"', port);
              for (i = 0; i < SCM_ROLENGTH (exp); ++i)
                switch (SCM_ROCHARS (exp)[i])
                  {
-                 case '\"':
+                 case '"':
                  case '\\':
                    scm_gen_putc ('\\', port);
                  default:
                    scm_gen_putc (SCM_ROCHARS (exp)[i], port);
                  }
-             scm_gen_putc ('\"', port);
+             scm_gen_putc ('"', port);
              break;
            }
          else
@@ -342,7 +411,7 @@ taloop:
              char * str;
              int weird;
              int maybe_weird;
-             int mw_pos;
+             int mw_pos = 0;
 
              len = SCM_LENGTH (exp);
              str = SCM_CHARS (exp);
@@ -363,7 +432,7 @@ taloop:
 #endif
                  case '(':
                  case ')':
-                 case '\"':
+                 case '"':
                  case ';':
                  case SCM_WHITE_SPACES:
                  case SCM_LINE_INCREMENTORS:
@@ -414,7 +483,7 @@ taloop:
              break;
            }
        case scm_tc7_wvect:
-         PUSH_REF (pstack, exp, circref);
+         ENTER_NESTED_DATA (pstate, exp, circref);
          if (SCM_IS_WHVEC (exp))
            scm_gen_puts (scm_regular_string, "#wh(", port);
          else
@@ -422,22 +491,22 @@ taloop:
          goto common_vector_printer;
 
        case scm_tc7_vector:
-         PUSH_REF (pstack, exp, circref);
+         ENTER_NESTED_DATA (pstate, exp, circref);
          scm_gen_puts (scm_regular_string, "#(", port);
        common_vector_printer:
          for (i = 0; i + 1 < SCM_LENGTH (exp); ++i)
            {
              /* CHECK_INTS; */
-             scm_iprin1 (SCM_VELTS (exp)[i], port, writing);
+             scm_iprin1 (SCM_VELTS (exp)[i], port, pstate);
              scm_gen_putc (' ', port);
            }
          if (i < SCM_LENGTH (exp))
            {
              /* CHECK_INTS; */
-             scm_iprin1 (SCM_VELTS (exp)[i], port, writing);
+             scm_iprin1 (SCM_VELTS (exp)[i], port, pstate);
            }
          scm_gen_putc (')', port);
-         POP_REF (pstack);
+         EXIT_NESTED_DATA (pstate);
          break;
        case scm_tc7_bvect:
        case scm_tc7_byvect:
@@ -450,7 +519,7 @@ taloop:
 #ifdef LONGLONGS
        case scm_tc7_llvect:
 #endif
-         scm_raprin1 (exp, port, writing);
+         scm_raprin1 (exp, port, pstate);
          break;
        case scm_tcs_subrs:
          scm_gen_puts (scm_regular_string, "#<primitive-procedure ", port);
@@ -463,7 +532,7 @@ taloop:
 #ifdef CCLO
        case scm_tc7_cclo:
          scm_gen_puts (scm_regular_string, "#<compiled-closure ", port);
-         scm_iprin1 (SCM_CCLO_SUBR (exp), port, writing);
+         scm_iprin1 (SCM_CCLO_SUBR (exp), port, pstate);
          scm_gen_putc ('>', port);
          break;
 #endif
@@ -476,19 +545,21 @@ taloop:
          break;
        case scm_tc7_port:
          i = SCM_PTOBNUM (exp);
-         if (i < scm_numptob && scm_ptobs[i].print && (scm_ptobs[i].print) (exp, port, writing))
+         if (i < scm_numptob
+             && scm_ptobs[i].print
+             && (scm_ptobs[i].print) (exp, port, pstate))
            break;
          goto punk;
        case scm_tc7_smob:
-         PUSH_REF (pstack, exp, circref);
+         ENTER_NESTED_DATA (pstate, exp, circref);
          i = SCM_SMOBNUM (exp);
          if (i < scm_numsmob && scm_smobs[i].print
-             && (scm_smobs[i].print) (exp, port, writing))
+             && (scm_smobs[i].print) (exp, port, pstate))
            {
-             POP_REF (pstack);
+             EXIT_NESTED_DATA (pstate);
              break;
            }
-         POP_REF (pstack);
+         EXIT_NESTED_DATA (pstate);
        default:
        punk:
          scm_ipruk ("type", exp, port);
@@ -496,34 +567,52 @@ taloop:
     }
 }
 
-#ifdef __STDC__
-void 
-scm_prin1 (SCM exp, SCM port, int writing)
-#else
+/* Print states are necessary for circular reference safe printing.
+ * They are also expensive to allocate.  Therefore print states are
+ * kept in a pool so that they can be reused.
+ */
+
 void 
-scm_prin1 (exp, port, writing)
+scm_prin1 (exp, port, writingp)
      SCM exp;
      SCM port;
-     int writing;
-#endif
+     int writingp;
 {
-  RESET_REF_STACK (pstack);
-  scm_iprin1 (exp, port, writing);
+  SCM handle = 0; /* Will GC protect the handle whilst unlinked */
+  scm_print_state *pstate;
+
+  /* First try to allocate a print state from the pool */
+  SCM_DEFER_INTS;
+  if (SCM_NNULLP (SCM_CDR (print_state_pool)))
+    {
+      handle = SCM_CDR (print_state_pool);
+      SCM_SETCDR (print_state_pool, SCM_CDDR (print_state_pool));
+    }
+  SCM_ALLOW_INTS;
+  
+  if (!handle)
+    handle = scm_cons (make_print_state (), SCM_EOL);
+
+  pstate = SCM_PRINT_STATE (SCM_CAR (handle));
+  pstate->writingp = writingp;
+  scm_iprin1 (exp, port, pstate);
+
+  /* Return print state to pool */
+  SCM_DEFER_INTS;
+  SCM_SETCDR (handle, SCM_CDR (print_state_pool));
+  SCM_SETCDR (print_state_pool, handle);
+  SCM_ALLOW_INTS;
 }
 
 
 /* Print an integer.
  */
-#ifdef __STDC__
-void 
-scm_intprint (long n, int radix, SCM port)
-#else
+
 void 
 scm_intprint (n, radix, port)
      long n;
      int radix;
      SCM port;
-#endif
 {
   char num_buf[SCM_INTBUFLEN];
   scm_gen_write (scm_regular_string, num_buf, scm_iint2str (n, radix, num_buf), port);
@@ -531,16 +620,12 @@ scm_intprint (n, radix, port)
 
 /* Print an object of unrecognized type.
  */
-#ifdef __STDC__
-void 
-scm_ipruk (char *hdr, SCM ptr, SCM port)
-#else
+
 void 
 scm_ipruk (hdr, ptr, port)
      char *hdr;
      SCM ptr;
      SCM port;
-#endif
 {
   scm_gen_puts (scm_regular_string, "#<unknown-", port);
   scm_gen_puts (scm_regular_string, hdr, port);
@@ -560,78 +645,120 @@ scm_ipruk (hdr, ptr, port)
 /* Print a list.
  */
 
-static ref_stack lstack;
 
-#ifdef __STDC__
 void 
-scm_iprlist (char *hdr, SCM exp, char tlr, SCM port, int writing)
-#else
-void 
-scm_iprlist (hdr, exp, tlr, port, writing)
+scm_iprlist (hdr, exp, tlr, port, pstate)
      char *hdr;
      SCM exp;
      char tlr;
      SCM port;
-     int writing;
-#endif
+     scm_print_state *pstate;
 {
+  register int i;
+  register SCM hare, tortoise;
+  int floor = pstate->top - 2;
   scm_gen_puts (scm_regular_string, hdr, port);
   /* CHECK_INTS; */
-  scm_iprin1 (SCM_CAR (exp), port, writing);
-  RESET_REF_STACK (lstack);
-  PUSH_REF (lstack, exp, circref);
+  if (pstate->fancyp)
+    goto fancy_printing;
+  
+  /* Run a hare and tortoise so that total time complexity will be
+     O(depth * N) instead of O(N^2). */
+  hare = SCM_CDR (exp);
+  tortoise = exp;
+  while (SCM_NIMP (hare) && SCM_ECONSP (hare))
+    {
+      if (hare == tortoise)
+       goto fancy_printing;
+      hare = SCM_CDR (hare);
+      if (SCM_IMP (hare) || SCM_NECONSP (hare))
+       break;
+      hare = SCM_CDR (hare);
+      tortoise = SCM_CDR (tortoise);
+    }
+  
+  /* No cdr cycles intrinsic to this list */
+  scm_iprin1 (SCM_CAR (exp), port, pstate);
   exp = SCM_CDR (exp);
   for (; SCM_NIMP (exp); exp = SCM_CDR (exp))
     {
       if (SCM_NECONSP (exp))
        break;
-      PUSH_REF (lstack, exp, circref);
+      for (i = floor; i >= 0; --i)
+       if (pstate->ref_stack[i] == exp)
+         goto circref;
+      PUSH_REF (pstate, exp);
       scm_gen_putc (' ', port);
       /* CHECK_INTS; */
-      scm_iprin1 (SCM_CAR (exp), port, writing);
+      scm_iprin1 (SCM_CAR (exp), port, pstate);
     }
   if (SCM_NNULLP (exp))
     {
       scm_gen_puts (scm_regular_string, " . ", port);
-      scm_iprin1 (exp, port, writing);
+      scm_iprin1 (exp, port, pstate);
     }
+
 end:
   scm_gen_putc (tlr, port);
+  pstate->top = floor + 2;
   return;
-circref:
-  scm_gen_puts (scm_regular_string, " . #<circ ref>", port);
+  
+fancy_printing:
+  {
+    int n = pstate->length;
+    
+    scm_iprin1 (SCM_CAR (exp), port, pstate);
+    exp = SCM_CDR (exp); --n;
+    for (; SCM_NIMP (exp); exp = SCM_CDR (exp))
+      {
+       if (SCM_NECONSP (exp))
+         break;
+       for (i = 0; i < pstate->top; ++i)
+         if (pstate->ref_stack[i] == exp)
+           goto fancy_circref;
+       if (pstate->fancyp)
+         {
+           if (n == 0)
+             {
+               scm_gen_puts (scm_regular_string, " ...", port);
+               goto skip_tail;
+             }
+           else
+             --n;
+         }
+       PUSH_REF(pstate, exp);
+       ++pstate->list_offset;
+       scm_gen_putc (' ', port);
+       /* CHECK_INTS; */
+       scm_iprin1 (SCM_CAR (exp), port, pstate);
+      }
+  }
+  if (SCM_NNULLP (exp))
+    {
+      scm_gen_puts (scm_regular_string, " . ", port);
+      scm_iprin1 (exp, port, pstate);
+    }
+skip_tail:
+  pstate->list_offset -= pstate->top - floor - 2;
   goto end;
-}
 
-#ifdef __STDC__
-void 
-scm_prlist (char *hdr, SCM exp, char tlr, SCM port, int writing)
-#else
-void 
-scm_prlist (hdr, exp, tlr, port, writing)
-     char *hdr;
-     SCM exp;
-     char tlr;
-     SCM port;
-     int writing;
-#endif
-{
-  RESET_REF_STACK (pstack);
-  scm_iprlist (hdr, exp, tlr, port, writing);
+fancy_circref:
+  pstate->list_offset -= pstate->top - floor - 2;
+  
+circref:
+  scm_gen_puts (scm_regular_string, " . ", port);
+  print_circref (port, pstate, exp);
+  goto end;
 }
 
 \f
 
 SCM_PROC(s_write, "write", 1, 1, 0, scm_write);
-#ifdef __STDC__
-SCM 
-scm_write (SCM obj, SCM port)
-#else
+
 SCM 
 scm_write (obj, port)
      SCM obj;
      SCM port;
-#endif
 {
   if (SCM_UNBNDP (port))
     port = scm_cur_outp;
@@ -649,15 +776,11 @@ scm_write (obj, port)
 
 
 SCM_PROC(s_display, "display", 1, 1, 0, scm_display);
-#ifdef __STDC__
-SCM 
-scm_display (SCM obj, SCM port)
-#else
+
 SCM 
 scm_display (obj, port)
      SCM obj;
      SCM port;
-#endif
 {
   if (SCM_UNBNDP (port))
     port = scm_cur_outp;
@@ -674,14 +797,10 @@ scm_display (obj, port)
 }
 
 SCM_PROC(s_newline, "newline", 0, 1, 0, scm_newline);
-#ifdef __STDC__
-SCM
-scm_newline(SCM port)
-#else
+
 SCM 
 scm_newline (port)
      SCM port;
-#endif
 {
   if (SCM_UNBNDP (port))
  port = scm_cur_outp;
@@ -701,15 +820,11 @@ scm_newline (port)
 }
 
 SCM_PROC(s_write_char, "write-char", 1, 1, 0, scm_write_char);
-#ifdef __STDC__
-SCM 
-scm_write_char (SCM chr, SCM port)
-#else
+
 SCM 
 scm_write_char (chr, port)
      SCM chr;
      SCM port;
-#endif
 {
   if (SCM_UNBNDP (port))
  port = scm_cur_outp;
@@ -729,18 +844,17 @@ scm_write_char (chr, port)
 
 \f
 
-#ifdef __STDC__
-void
-scm_init_print (void)
-#else
+
 void
 scm_init_print ()
-#endif
 {
-#ifdef DEBUG_EXTENSIONS
+  SCM vtable, type;
   scm_init_opts (scm_print_options, scm_print_opts, SCM_N_PRINT_OPTIONS);
-  init_ref_stack (&pstack);
-  init_ref_stack (&lstack);
-#endif
+  vtable = scm_make_vtable_vtable (scm_make_struct_layout (scm_nullstr), SCM_INUM0, SCM_EOL);
+  type = scm_make_struct (vtable,
+                         SCM_INUM0,
+                         scm_cons (scm_make_struct_layout (scm_makfrom0str (SCM_PRINT_STATE_LAYOUT)),
+                                   SCM_EOL));
+  print_state_pool = scm_permanent_object (scm_cons (type, SCM_EOL));
 #include "print.x"
 }