4.3BSD/usr/contrib/emacs/src/print.c

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/* Lisp object printing and output streams.
   Copyright (C) 1985 Richard M. Stallman.

This file is part of GNU Emacs.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the GNU Emacs General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
GNU Emacs, but only under the conditions described in the
GNU Emacs General Public License.   A copy of this license is
supposed to have been given to you along with GNU Emacs so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.  */


#include "config.h"
#include <stdio.h>
#undef NULL
#include "lisp.h"

#ifndef standalone
#include "buffer.h"
#include "window.h"
#include "process.h"
#endif /* not standalone */

Lisp_Object Vstandard_output, Qstandard_output;

/* Avoid actual stack overflow in print.  */
int print_depth;

/* Maximum length of list to print in full; noninteger means
   effectively infinity */

Lisp_Object Vprint_length;

/* Nonzero means print newline before next minibuffer message.
   Defined in xdisp.c */

extern int noninteractive_need_newline;

/* Low level output routines for charaters and strings */

/* Lisp functions to do output using a stream
 must have the stream in a variable called printcharfun
 and must start with PRINTPREPARE and end with PRINTFINISH.
 Use PRINTCHAR to output one character,
 or call strout to output a block of characters.
 Also, each one must have the declarations
   struct buffer *old = bf_cur;
   int old_point = -1, start_point;
   Lisp_Object original;
*/ 

#define PRINTPREPARE \
   original = printcharfun; \
   if (NULL (printcharfun)) printcharfun = Qt; \
   if (XTYPE (printcharfun) == Lisp_Buffer) \
     { if (XBUFFER (printcharfun) != bf_cur) SetBfp (XBUFFER (printcharfun)); \
       printcharfun = Qnil;}\
   if (XTYPE (printcharfun) == Lisp_Marker) \
     { if (XMARKER (original)->buffer != bf_cur) \
         SetBfp (XMARKER (original)->buffer); \
       old_point = point; \
       SetPoint (marker_position (printcharfun)); \
       start_point = point; \
       printcharfun = Qnil;}

#define PRINTFINISH \
   if (XTYPE (original) == Lisp_Marker) \
     Fset_marker (original, make_number (point), Qnil); \
   if (old_point >= 0) \
     SetPoint ((old_point >= start_point ? point - start_point : 0) + old_point); \
   if (old != bf_cur) \
     SetBfp (old)

#define PRINTCHAR(ch) printchar (ch, printcharfun)

/* Buffer for output destined for minibuffer */
static char printbuf[MScreenWidth + 1];
/* Index of first unused element of above */
static int printbufidx;

static void
printchar (ch, fun)
     unsigned char ch;
     Lisp_Object fun;
{
  Lisp_Object ch1;

#ifndef standalone
  if (EQ (fun, Qnil))
    {
      QUIT;
      InsCStr (&ch, 1);
      return;
    }
  if (EQ (fun, Qt))
    {
      if (noninteractive)
	{
	  putchar (ch);
	  noninteractive_need_newline = 1;
	  return;
	}
      if (minibuf_message != printbuf)
	minibuf_message = printbuf, printbufidx = 0;
      if (printbufidx < sizeof printbuf - 1)
	printbuf[printbufidx++] = ch;
      printbuf[printbufidx] = 0;
      return;
    }
#endif /* not standalone */

  XFASTINT (ch1) = ch;
  call1 (fun, ch1);
}

static void
strout (ptr, size, printcharfun)
     char *ptr;
     int size;
     Lisp_Object printcharfun;
{
  int i = 0;

  if (EQ (printcharfun, Qnil))
    {
      InsCStr (ptr, size >= 0 ? size : strlen (ptr));
      return;
    }
  if (EQ (printcharfun, Qt))
    {
      i = size >= 0 ? size : strlen (ptr);
      if (noninteractive)
	{
	  fwrite (ptr, 1, i, stdout);
	  noninteractive_need_newline = 1;
	  return;
	}
      if (minibuf_message != printbuf)
	minibuf_message = printbuf, printbufidx = 0;
      if (i > sizeof printbuf - printbufidx - 1)
	i = sizeof printbuf - printbufidx - 1;
      bcopy (ptr, &printbuf[printbufidx], i);
      printbufidx += i;
      printbuf[printbufidx] = 0;
      return;
    }
  if (size >= 0)
    while (i < size)
      PRINTCHAR (ptr[i++]);
  else
    while (ptr[i])
      PRINTCHAR (ptr[i++]);
}

DEFUN ("write-char", Fwrite_char, Swrite_char, 1, 2, 0,
  "Output character CHAR to stream STREAM.\n\
STREAM defaults to the value of standard-output (which see).")
  (ch, printcharfun)
     Lisp_Object ch, printcharfun;
{
  struct buffer *old = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  CHECK_NUMBER (ch, 0);
  PRINTPREPARE;
  PRINTCHAR (XINT (ch));
  PRINTFINISH;
  return ch;
}

write_string (data, size)
     char *data;
     int size;
{
  struct buffer *old = bf_cur;
  Lisp_Object printcharfun;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  printcharfun = Vstandard_output;

  PRINTPREPARE;
  strout (data, size, printcharfun);
  PRINTFINISH;
}

write_string_1 (data, size, printcharfun)
     char *data;
     int size;
     Lisp_Object printcharfun;
{
  struct buffer *old = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  PRINTPREPARE;
  strout (data, size, printcharfun);
  PRINTFINISH;
}


#ifndef standalone

temp_output_buffer_setup (bufname)
    char *bufname;
{
  register struct buffer *old = bf_cur;
  register Lisp_Object buf;

  Fset_buffer (Fget_buffer_create (build_string (bufname)));

  bf_cur->read_only = Qnil;
  Ferase_buffer ();

  XSET (buf, Lisp_Buffer, bf_cur);
  specbind (Qstandard_output, buf);

  SetBfp (old);
}

Lisp_Object
internal_with_output_to_temp_buffer (bufname, function, args)
     char *bufname;
     Lisp_Object (*function) ();
     Lisp_Object args;
{
  int count = specpdl_ptr - specpdl;
  Lisp_Object buf, val;

  temp_output_buffer_setup (bufname);
  buf = Vstandard_output;

  val = (*function) (args);

  temp_output_buffer_show (buf);

  unbind_to (count);
  return val;
}

DEFUN ("with-output-to-temp-buffer", Fwith_output_to_temp_buffer, Swith_output_to_temp_buffer,
       1, UNEVALLED, 0,
  "Binding  standard-output  to buffer named BUFNAME, execute BODY then display the buffer.\n\
The buffer is cleared out initially, and marked as unmodified when done.\n\
All output done by BODY is inserted in that buffer by default.\n\
It is displayed in another window, but not selected.\n\
The value of the last form in BODY is returned.")
  (args)
     Lisp_Object args;
{
  struct gcpro gcpro1;
  Lisp_Object name;
  int count = specpdl_ptr - specpdl;
  Lisp_Object buf, val;

  GCPRO1(args);
  name = Feval (Fcar (args));
  UNGCPRO;

  temp_output_buffer_setup (XSTRING (name)->data);
  buf = Vstandard_output;

  val = Fprogn (args);

  temp_output_buffer_show (buf);

  unbind_to (count);
  return val;
}
#endif /* not standalone */

static void print ();

DEFUN ("terpri", Fterpri, Sterpri, 0, 1, 0,
  "Output a newline to STREAM (or value of standard-output).")
  (printcharfun)
     Lisp_Object printcharfun;
{
  struct buffer *old = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  if (NULL (printcharfun))
    printcharfun = Vstandard_output;
  PRINTPREPARE;
  PRINTCHAR ('\n');
  PRINTFINISH;
  return Qt;
}

DEFUN ("prin1", Fprin1, Sprin1, 1, 2, 0,
  "Output the printed representation of OBJECT, any Lisp object.\n\
Quoting characters are used, to make output that  read  can handle\n\
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 = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  if (NULL (printcharfun))
    printcharfun = Vstandard_output;
  PRINTPREPARE;
  print_depth = 0;
  print (obj, printcharfun, 1);
  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, to make output that  read\n\
can handle whenever this is possible.")
  (obj)
     Lisp_Object obj;
{
  struct buffer *old = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original, printcharfun;

  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;
  SetBfp (XBUFFER (Vprin1_to_string_buffer));
  obj = Fbuffer_string ();
  Ferase_buffer ();
  SetBfp (old);
  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 = bf_cur;
  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 newline before and\n\
space after.  Quoting characters are used, 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 = bf_cur;
  int old_point = -1;
  int start_point;
  Lisp_Object original;

  if (NULL (printcharfun))
    printcharfun = Vstandard_output;
  PRINTPREPARE;
  print_depth = 0;
  PRINTCHAR ('\n');
  print (obj, printcharfun, 1);
  PRINTCHAR ('\n');
  PRINTFINISH;
  return obj;
}

static void
print (obj, printcharfun, escapeflag)
     register Lisp_Object obj;
     Lisp_Object printcharfun;
     int escapeflag;
{
  char buf[30];

  QUIT;

  print_depth++;
  if (print_depth > 200)
    error ("Apparently circular structure being printed");

#ifdef SWITCH_ENUM_BUG
  switch ((int) XTYPE (obj))
#else
  switch (XTYPE (obj))
#endif
    {
    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 == '\"' || 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 (LISTP (obj))
	  {
	    if (i++)
	      PRINTCHAR (' ');
	    if (max && i > max)
	      {
		strout ("...", 3, printcharfun);
		break;
	      }
	    print (Fcar (obj), printcharfun, escapeflag);
	    obj = Fcdr (obj);
	  }
      }
      if (!NULL (obj) && !LISTP (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))
	{
	  strout (" on ", -1, printcharfun);
	  strout (XSTRING (XBUFFER (XWINDOW (obj)->buffer)->name)->data,
		  -1, printcharfun);
	}
      PRINTCHAR ('>');
      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 ()
{
  DefLispVar ("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);

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

  /* 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 */
}