print.c

早期freebsd实现

  PRINTFINISH;
  return obj;
}

/* a buffer which is used to hold output being built by prin1-to-string */
Lisp_Object Vprin1_to_string_buffer;

DEFUN ("prin1-to-string", Fprin1_to_string, Sprin1_to_string, 1, 1, 0,
  "Return a string containing the printed representation of OBJECT,\n\
any Lisp object.  Quoting characters are used when needed to make output\n\
that `read' can handle, whenever this is possible.")
  (obj)
     Lisp_Object obj;
{
  struct buffer *old = current_buffer;
  int old_point = -1;
  int start_point;
  Lisp_Object original, printcharfun;
  struct gcpro gcpro1;

  printcharfun = Vprin1_to_string_buffer;
  PRINTPREPARE;
  print_depth = 0;
  print (obj, printcharfun, 1);
  /* Make Vprin1_to_string_buffer be the default buffer after PRINTFINSH */
  PRINTFINISH;
  set_buffer_internal (XBUFFER (Vprin1_to_string_buffer));
  obj = Fbuffer_string ();
  GCPRO1 (obj);
  Ferase_buffer ();
  set_buffer_internal (old);
  UNGCPRO;
  return obj;
}

DEFUN ("princ", Fprinc, Sprinc, 1, 2, 0,
  "Output the printed representation of OBJECT, any Lisp object.\n\
No quoting characters are used; no delimiters are printed around\n\
the contents of strings.\n\
Output stream is STREAM, or value of standard-output (which see).")
  (obj, printcharfun)
     Lisp_Object obj, printcharfun;
{
  struct buffer *old = current_buffer;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  if (NULL (printcharfun))
    printcharfun = Vstandard_output;
  PRINTPREPARE;
  print_depth = 0;
  print (obj, printcharfun, 0);
  PRINTFINISH;
  return obj;
}

DEFUN ("print", Fprint, Sprint, 1, 2, 0,
  "Output the printed representation of OBJECT, with newlines around it.\n\
Quoting characters are printed when needed to make output that `read'\n\
can handle, whenever this is possible.\n\
Output stream is STREAM, or value of `standard-output' (which see).")
  (obj, printcharfun)
     Lisp_Object obj, printcharfun;
{
  struct buffer *old = current_buffer;
  int old_point = -1;
  int start_point;
  Lisp_Object original;
  struct gcpro gcpro1;

#ifdef MAX_PRINT_CHARS
  print_chars = 0;
  max_print = MAX_PRINT_CHARS;
#endif /* MAX_PRINT_CHARS */
  if (NULL (printcharfun))
    printcharfun = Vstandard_output;
  GCPRO1 (obj);
  PRINTPREPARE;
  print_depth = 0;
  PRINTCHAR ('\n');
  print (obj, printcharfun, 1);
  PRINTCHAR ('\n');
  PRINTFINISH;
#ifdef MAX_PRINT_CHARS
  max_print = 0;
  print_chars = 0;
#endif /* MAX_PRINT_CHARS */
  UNGCPRO;
  return obj;
}

static void
print (obj, printcharfun, escapeflag)
#ifndef RTPC_REGISTER_BUG
     register Lisp_Object obj;
#else
     Lisp_Object obj;
#endif
     register Lisp_Object printcharfun;
     int escapeflag;
{
  char buf[30];

  QUIT;

  print_depth++;
  if (print_depth > 200)
    error ("Apparently circular structure being printed");
#ifdef MAX_PRINT_CHARS
  if (max_print && print_chars > max_print)
    {
      PRINTCHAR ('\n');
      print_chars = 0;
    }
#endif /* MAX_PRINT_CHARS */

#ifdef SWITCH_ENUM_BUG
  switch ((int) XTYPE (obj))
#else
  switch (XTYPE (obj))
#endif
    {
    default:
      /* We're in trouble if this happens!
	 Probably should just abort () */
      strout ("#<EMACS BUG: INVALID DATATYPE ", -1, printcharfun);
      sprintf (buf, "(#o%3o)", (int) XTYPE (obj));
      strout (buf, -1, printcharfun);
      strout (" Save your buffers immediately and please report this bug>",
	      -1, printcharfun);
      break;

    case Lisp_Int:
      sprintf (buf, "%d", XINT (obj));
      strout (buf, -1, printcharfun);
      break;

    case Lisp_String:
      if (!escapeflag)
	strout (XSTRING (obj)->data, XSTRING (obj)->size, printcharfun);
      else
	{
	  register int i;
	  register unsigned char *p = XSTRING (obj)->data;
	  register unsigned char c;

	  PRINTCHAR ('\"');
	  for (i = XSTRING (obj)->size; i > 0; i--)
	    {
	      QUIT;
	      c = *p++;
	      if (c == '\n' && print_escape_newlines)
		{
		  PRINTCHAR ('\\');
		  PRINTCHAR ('n');
		}
	      else
		{
		  if (c == '\"' || c == '\\')
		    PRINTCHAR ('\\');
		  PRINTCHAR (c);
		}
	    }
	  PRINTCHAR ('\"');
	}
      break;

    case Lisp_Symbol:
      {
	register int confusing;
	register unsigned char *p = XSYMBOL (obj)->name->data;
	register unsigned char *end = p + XSYMBOL (obj)->name->size;
	register unsigned char c;

	if (p != end && (*p == '-' || *p == '+')) p++;
        if (p == end)
	  confusing = 0;
	else
	  {
	    while (p != end && *p >= '0' && *p <= '9')
	      p++;
	    confusing = (end == p);
	  }

	p = XSYMBOL (obj)->name->data;
	while (p != end)
	  {
	    QUIT;
	    c = *p++;
	    if (escapeflag)
	      {
		if (c == '\"' || c == '\\' || c == '\'' || c == ';' || c == '#' ||
		    c == '(' || c == ')' || c == ',' || c =='.' || c == '`' ||
		    c == '[' || c == ']' || c == '?' || c <= 040 || confusing)
		  PRINTCHAR ('\\'), confusing = 0;
	      }
	    PRINTCHAR (c);
	  }
      }
      break;

    case Lisp_Cons:
      PRINTCHAR ('(');
      {
	register int i = 0;
	register int max = 0;

	if (XTYPE (Vprint_length) == Lisp_Int)
	  max = XINT (Vprint_length);
	while (CONSP (obj))
	  {
	    if (i++)
	      PRINTCHAR (' ');
	    if (max && i > max)
	      {
		strout ("...", 3, printcharfun);
		break;
	      }
	    print (Fcar (obj), printcharfun, escapeflag);
	    obj = Fcdr (obj);
	  }
      }
      if (!NULL (obj) && !CONSP (obj))
	{
	  strout (" . ", 3, printcharfun);
	  print (obj, printcharfun, escapeflag);
	}
      PRINTCHAR (')');
      break;

    case Lisp_Vector:
      PRINTCHAR ('[');
      {
	register int i;
	register Lisp_Object tem;
	for (i = 0; i < XVECTOR (obj)->size; i++)
	  {
	    if (i) PRINTCHAR (' ');
	    tem = XVECTOR (obj)->contents[i];
	    print (tem, printcharfun, escapeflag);
	  }
      }
      PRINTCHAR (']');
      break;

#ifndef standalone
    case Lisp_Buffer:
      if (NULL (XBUFFER (obj)->name))
	strout ("#<killed buffer>", -1, printcharfun);
      else if (escapeflag)
	{
	  strout ("#<buffer ", -1, printcharfun);
	  strout (XSTRING (XBUFFER (obj)->name)->data, -1, printcharfun);
	  PRINTCHAR ('>');
	}
      else
	strout (XSTRING (XBUFFER (obj)->name)->data, -1, printcharfun);
      break;

    case Lisp_Process:
      if (escapeflag)
	{
	  strout ("#<process ", -1, printcharfun);
	  strout (XSTRING (XPROCESS (obj)->name)->data, -1, printcharfun);
	  PRINTCHAR ('>');
	}
      else
	strout (XSTRING (XPROCESS (obj)->name)->data, -1, printcharfun);
      break;

    case Lisp_Window:
      strout ("#<window ", -1, printcharfun);
      sprintf (buf, "%d", XFASTINT (XWINDOW (obj)->sequence_number));
      strout (buf, -1, printcharfun);
      if (!NULL (XWINDOW (obj)->buffer))
	{
	  unsigned char *p = XSTRING (XBUFFER (XWINDOW (obj)->buffer)->name)->data;
	  strout (" on ", -1, printcharfun);
	  strout (p, -1, printcharfun);
	}
      PRINTCHAR ('>');
      break;

    case Lisp_Window_Configuration:
      strout ("#<window-configuration>", -1, printcharfun);
      break;

    case Lisp_Marker:
      strout ("#<marker ", -1, printcharfun);
      if (!(XMARKER (obj)->buffer))
	strout ("in no buffer", -1, printcharfun);
      else
	{
	  sprintf (buf, "at %d", marker_position (obj));
	  strout (buf, -1, printcharfun);
	  strout (" in ", -1, printcharfun);
	  strout (XSTRING (XMARKER (obj)->buffer->name)->data, -1, printcharfun);
	}
      PRINTCHAR ('>');
      break;
#endif /* standalone */

    case Lisp_Subr:
      strout ("#<subr ", -1, printcharfun);
      strout (XSUBR (obj)->symbol_name, -1, printcharfun);
      PRINTCHAR ('>');
      break;
    }

  print_depth--;
}

void
syms_of_print ()
{
  DEFVAR_LISP ("standard-output", &Vstandard_output,
    "Function print uses by default for outputting a character.\n\
This may be any function of one argument.\n\
It may also be a buffer (output is inserted before point)\n\
or a marker (output is inserted and the marker is advanced)\n\
or the symbol t (output appears in the minibuffer line).");
  Vstandard_output = Qt;
  Qstandard_output = intern ("standard-output");
  staticpro (&Qstandard_output);

  DEFVAR_LISP ("print-length", &Vprint_length,
    "Maximum length of list to print before abbreviating.\
`nil' means no limit.");
  Vprint_length = Qnil;

  DEFVAR_BOOL ("print-escape-newlines", &print_escape_newlines,
    "Non-nil means print newlines in strings as backslash-n.");
  print_escape_newlines = 0;

  /* prin1_to_string_buffer initialized in init_buffer_once in buffer.c */
  staticpro (&Vprin1_to_string_buffer);

  defsubr (&Sprin1);
  defsubr (&Sprin1_to_string);
  defsubr (&Sprinc);
  defsubr (&Sprint);
  defsubr (&Sterpri);
  defsubr (&Swrite_char);
#ifndef standalone
  defsubr (&Swith_output_to_temp_buffer);
#endif /* not standalone */
}