view src/minibuf.c @ 853:2b6fa2618f76

[xemacs-hg @ 2002-05-28 08:44:22 by ben] merge my stderr-proc ws make-docfile.c: Fix places where we forget to check for EOF. code-init.el: Don't use CRLF conversion by default on process output. CMD.EXE and friends work both ways but Cygwin programs don't like the CRs. code-process.el, multicast.el, process.el: Removed. Improvements to call-process-internal: -- allows a buffer to be specified for input and stderr output -- use it on all systems -- implement C-g as documented -- clean up and comment call-process-region uses new call-process facilities; no temp file. remove duplicate funs in process.el. comment exactly how coding systems work and fix various problems. open-multicast-group now does similar coding-system frobbing to open-network-stream. dumped-lisp.el, faces.el, msw-faces.el: Fix some hidden errors due to code not being defined at the right time. xemacs.mak: Add -DSTRICT. ================================================================ ALLOW SEPARATION OF STDOUT AND STDERR IN PROCESSES ================================================================ Standard output and standard error can be processed separately in a process. Each can have its own buffer, its own mark in that buffer, and its filter function. You can specify a separate buffer for stderr in `start-process' to get things started, or use the new primitives: set-process-stderr-buffer process-stderr-buffer process-stderr-mark set-process-stderr-filter process-stderr-filter Also, process-send-region takes a 4th optional arg, a buffer. Currently always uses a pipe() under Unix to read the error output. (#### Would a PTY be better?) sysdep.h, sysproc.h, unexfreebsd.c, unexsunos4.c, nt.c, emacs.c, callproc.c, symsinit.h, sysdep.c, Makefile.in.in, process-unix.c: Delete callproc.c. Move child_setup() to process-unix.c. wait_for_termination() now only needed on a few really old systems. console-msw.h, event-Xt.c, event-msw.c, event-stream.c, event-tty.c, event-unixoid.c, events.h, process-nt.c, process-unix.c, process.c, process.h, procimpl.h: Rewrite the process methods to handle a separate channel for error input. Create Lstreams for reading in the error channel. Many process methods need change. In general the changes are fairly clear as they involve duplicating what's used for reading the normal stdout and changing for stderr -- although tedious, as such changes are required throughout the entire process code. Rewrote the code that reads process output to do two loops, one for stdout and one for stderr. gpmevent.c, tooltalk.c: set_process_filter takes an argument for stderr. ================================================================ NEW ERROR-TRAPPING MECHANISM ================================================================ Totally rewrite error trapping code to be unified and support more features. Basic function is call_trapping_problems(), which lets you specify, by means of flags, what sorts of problems you want trapped. these can include -- quit -- errors -- throws past the function -- creation of "display objects" (e.g. buffers) -- deletion of already-existing "display objects" (e.g. buffers) -- modification of already-existing buffers -- entering the debugger -- gc -- errors->warnings (ala suspended errors) etc. All other error funs rewritten in terms of this one. Various older mechanisms removed or rewritten. window.c, insdel.c, console.c, buffer.c, device.c, frame.c: When creating a display object, added call to note_object_created(), for use with trapping_problems mechanism. When deleting, call check_allowed_operation() and note_object deleted(). The trapping-problems code records the objects created since the call-trapping-problems began. Those objects can be deleted, but none others (i.e. previously existing ones). bytecode.c, cmdloop.c: internal_catch takes another arg. eval.c: Add long comments describing the "five lists" used to maintain state (backtrace, gcpro, specbind, etc.) in the Lisp engine. backtrace.h, eval.c: Implement trapping-problems mechanism, eliminate old mechanisms or redo in terms of new one. frame.c, gutter.c: Flush out the concept of "critical display section", defined by the in_display() var. Use an internal_bind() to get it reset, rather than just doing it at end, because there may be a non-local exit. event-msw.c, event-stream.c, console-msw.h, device.c, dialog-msw.c, frame.c, frame.h, intl.c, toolbar.c, menubar-msw.c, redisplay.c, alloc.c, menubar-x.c: Make use of new trapping-errors stuff and rewrite code based on old mechanisms. glyphs-widget.c, redisplay.h: Protect calling Lisp in redisplay. insdel.c: Protect hooks against deleting existing buffers. frame-msw.c: Use EQ, not EQUAL in hash tables whose keys are just numbers. Otherwise we run into stickiness in redisplay because internal_equal() can QUIT. ================================================================ SIGNAL, C-G CHANGES ================================================================ Here we change the way that C-g interacts with event reading. The idea is that a C-g occurring while we're reading a user event should be read as C-g, but elsewhere should be a QUIT. The former code did all sorts of bizarreness -- requiring that no QUIT occurs anywhere in event-reading code (impossible to enforce given the stuff called or Lisp code invoked), and having some weird system involving enqueue/dequeue of a C-g and interaction with Vquit_flag -- and it didn't work. Now, we simply enclose all code where we want C-g read as an event with {begin/end}_dont_check_for_quit(). This completely turns off the mechanism that checks (and may remove or alter) C-g in the read-ahead queues, so we just get the C-g normal. Signal.c documents this very carefully. cmdloop.c: Correct use of dont_check_for_quit to new scheme, remove old out-of-date comments. event-stream.c: Fix C-g handling to actually work. device-x.c: Disable quit checking when err out. signal.c: Cleanup. Add large descriptive comment. process-unix.c, process-nt.c, sysdep.c: Use QUIT instead of REALLY_QUIT. It's not necessary to use REALLY_QUIT and just confuses the issue. lisp.h: Comment quit handlers. ================================================================ CONS CHANGES ================================================================ free_cons() now takes a Lisp_Object not the result of XCONS(). car and cdr have been renamed so that they don't get used directly; go through XCAR(), XCDR() instead. alloc.c, dired.c, editfns.c, emodules.c, fns.c, glyphs-msw.c, glyphs-x.c, glyphs.c, keymap.c, minibuf.c, search.c, eval.c, lread.c, lisp.h: Correct free_cons calling convention: now takes Lisp_Object, not Lisp_Cons chartab.c: Eliminate direct use of ->car, ->cdr, should be black box. callint.c: Rewrote using EXTERNAL_LIST_LOOP to avoid use of Lisp_Cons. ================================================================ USE INTERNAL-BIND-* ================================================================ eval.c: Cleanups of these funs. alloc.c, fileio.c, undo.c, specifier.c, text.c, profile.c, lread.c, redisplay.c, menubar-x.c, macros.c: Rewrote to use internal_bind_int() and internal_bind_lisp_object() in place of whatever varied and cumbersome mechanisms were formerly there. ================================================================ SPECBIND SANITY ================================================================ backtrace.h: - Improved comments backtrace.h, bytecode.c, eval.c: Add new mechanism check_specbind_stack_sanity() for sanity checking code each time the catchlist or specbind stack change. Removed older prototype of same mechanism. ================================================================ MISC ================================================================ lisp.h, insdel.c, window.c, device.c, console.c, buffer.c: Fleshed out authorship. device-msw.c: Correct bad Unicode-ization. print.c: Be more careful when not initialized or in fatal error handling. search.c: Eliminate running_asynch_code, an FSF holdover. alloc.c: Added comments about gc-cons-threshold. dialog-x.c: Use begin_gc_forbidden() around code to build up a widget value tree, like in menubar-x.c. gui.c: Use Qunbound not Qnil as the default for gethash. lisp-disunion.h, lisp-union.h: Added warnings on use of VOID_TO_LISP(). lisp.h: Use ERROR_CHECK_STRUCTURES to turn on ERROR_CHECK_TRAPPING_PROBLEMS and ERROR_CHECK_TYPECHECK lisp.h: Add assert_with_message. lisp.h: Add macros for gcproing entire arrays. (You could do this before but it required manual twiddling the gcpro structure.) lisp.h: Add prototypes for new functions defined elsewhere.
author ben
date Tue, 28 May 2002 08:45:36 +0000
parents 6728e641994e
children 804517e16990
line wrap: on
line source

/* Minibuffer input and completion.
   Copyright (C) 1985, 1986, 1992-1995 Free Software Foundation, Inc.
   Copyright (C) 1995 Sun Microsystems, Inc.
   Copyright (C) 2002 Ben Wing.

This file is part of XEmacs.

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Mule 2.0, FSF 19.28.  Mule-ized except as noted.
   Substantially different from FSF. */

/* #### dmoore - All sorts of things in here can call lisp, like message.
   Track all this stuff. */

#include <config.h>
#include "lisp.h"

#include "buffer.h"
#include "commands.h"
#include "console-stream.h"
#include "events.h"
#include "frame.h"
#include "insdel.h"
#include "redisplay.h"
#include "window.h"

/* Depth in minibuffer invocations.  */
int minibuf_level;

Lisp_Object Qcompletion_ignore_case;

/* Nonzero means completion ignores case.  */
int completion_ignore_case;

/* List of regexps that should restrict possible completions.  */
Lisp_Object Vcompletion_regexp_list;

/* The echo area buffer. */
Lisp_Object Vecho_area_buffer;

/* Prompt to display in front of the minibuffer contents */
Lisp_Object Vminibuf_prompt;

/* Added on 97/3/14 by Jareth Hein (jhod@po.iijnet.or.jp) for input system support */
/* String to be displayed in front of prompt of the minibuffer contents */
Lisp_Object Vminibuf_preprompt;

/* Hook to run just after entry to minibuffer. */
Lisp_Object Qminibuffer_setup_hook, Vminibuffer_setup_hook;

Lisp_Object Qappend_message, Qcurrent_message_label,
            Qclear_message, Qdisplay_message;


DEFUN ("minibuffer-depth", Fminibuffer_depth, 0, 0, 0, /*
Return current depth of activations of minibuffer, a nonnegative integer.
*/
       ())
{
  return make_int (minibuf_level);
}

/* The default buffer to use as the window-buffer of minibuffer windows */
/*  Note there is special code in kill-buffer to make this unkillable */
Lisp_Object Vminibuffer_zero;


/* Actual minibuffer invocation. */

static Lisp_Object
read_minibuffer_internal_unwind (Lisp_Object unwind_data)
{
  Lisp_Object frame;
  XWINDOW (minibuf_window)->last_modified[CURRENT_DISP] = Qzero;
  XWINDOW (minibuf_window)->last_modified[DESIRED_DISP] = Qzero;
  XWINDOW (minibuf_window)->last_modified[CMOTION_DISP] = Qzero;
  XWINDOW (minibuf_window)->last_facechange[CURRENT_DISP] = Qzero;
  XWINDOW (minibuf_window)->last_facechange[DESIRED_DISP] = Qzero;
  XWINDOW (minibuf_window)->last_facechange[CMOTION_DISP] = Qzero;
  Vminibuf_prompt = Felt (unwind_data, Qzero);
  minibuf_level = XINT (Felt (unwind_data, make_int (1)));
  while (CONSP (unwind_data))
    {
      Lisp_Object victim = unwind_data;
      unwind_data = XCDR (unwind_data);
      free_cons (victim);
    }

  /* If cursor is on the minibuffer line,
     show the user we have exited by putting it in column 0.  */
  frame = Fselected_frame (Qnil);
  if (!noninteractive
      && !NILP (frame)
      && !NILP (XFRAME (frame)->minibuffer_window))
    {
      struct window *w = XWINDOW (XFRAME (frame)->minibuffer_window);
      redisplay_move_cursor (w, 0, 0);
    }

  return Qnil;
}

/* 97/4/13 jhod: Added for input methods */
DEFUN ("set-minibuffer-preprompt", Fset_minibuffer_preprompt, 1, 1, 0, /*
Set the minibuffer preprompt string to PREPROMPT. This is used by language
input methods to relay state information to the user.
*/
       (preprompt))
{
  if (NILP (preprompt))
    {
      Vminibuf_preprompt = Qnil;
    }
  else
    {
      CHECK_STRING (preprompt);

      Vminibuf_preprompt = LISP_GETTEXT (preprompt);
    }
  return Qnil;
}

DEFUN ("read-minibuffer-internal", Fread_minibuffer_internal, 1, 1, 0, /*
Lowest-level interface to minibuffers.  Don't call this.
*/
       (prompt))
{
  /* This function can GC */
  int speccount = specpdl_depth ();
  Lisp_Object val;

  CHECK_STRING (prompt);

  single_console_state ();

  record_unwind_protect (read_minibuffer_internal_unwind,
                         noseeum_cons
			 (Vminibuf_prompt,
			  noseeum_cons (make_int (minibuf_level), Qnil)));
  Vminibuf_prompt = LISP_GETTEXT (prompt);

  /* NOTE: Here (or somewhere around here), in FSFmacs 19.30,
     choose_minibuf_frame() is called.  This is the only
     place in FSFmacs that it's called any more -- there's
     also a call in xterm.c, but commented out, and 19.28
     had the calls in different places.

     choose_minibuf_frame() does the following:

  if (!EQ (minibuf_window, selected_frame()->minibuffer_window))
    {
      Fset_window_buffer (selected_frame()->minibuffer_window,
			  XWINDOW (minibuf_window)->buffer);
      minibuf_window = selected_frame()->minibuffer_window;
    }

  #### Note that we don't do the set-window-buffer.  This call is
  similar, but not identical, to a set-window-buffer call made
  in `read-from-minibuffer' in minibuf.el.  I hope it's close
  enough, because minibuf_window isn't really exported to Lisp.

  The comment above choose_minibuf_frame() reads:

  Put minibuf on currently selected frame's minibuffer.
  We do this whenever the user starts a new minibuffer
  or when a minibuffer exits.  */

  minibuf_window = FRAME_MINIBUF_WINDOW (selected_frame ());

  run_hook (Qminibuffer_setup_hook);

  minibuf_level++;
  clear_echo_area (selected_frame (), Qnil, 0);

  val = call_command_loop (Qt);

  return unbind_to_1 (speccount, val);
}



/* Completion hair */

/* Compare exactly LEN chars of strings at S1 and S2,
   ignoring case if appropriate.
   Return -1 if strings match,
   else number of chars that match at the beginning.  */

/* Note that this function works in Charcounts, unlike most functions.
   This is necessary for many reasons, one of which is that two
   strings may match even if they have different numbers of bytes,
   if IGNORE_CASE is true. */

Charcount
scmp_1 (const Intbyte *s1, const Intbyte *s2, Charcount len,
	int ignore_case)
{
  Charcount l = len;

  if (ignore_case)
    {
      while (l)
        {
          Emchar c1 = DOWNCASE (0, charptr_emchar (s1));
          Emchar c2 = DOWNCASE (0, charptr_emchar (s2));

          if (c1 == c2)
            {
              l--;
              INC_CHARPTR (s1);
              INC_CHARPTR (s2);
            }
          else
            break;
        }
    }
  else
    {
      while (l && charptr_emchar (s1) == charptr_emchar (s2))
	{
	  l--;
	  INC_CHARPTR (s1);
	  INC_CHARPTR (s2);
	}
    }

  if (l == 0)
    return -1;
  else return len - l;
}


int
regexp_ignore_completion_p (const Intbyte *nonreloc,
			    Lisp_Object reloc, Bytecount offset,
			    Bytecount length)
{
  /* Ignore this element if it fails to match all the regexps.  */
  if (!NILP (Vcompletion_regexp_list))
    {
      Lisp_Object regexps;
      EXTERNAL_LIST_LOOP (regexps, Vcompletion_regexp_list)
	{
	  Lisp_Object re = XCAR (regexps);
	  CHECK_STRING (re);
	  if (fast_string_match (re, nonreloc, reloc, offset,
				 length, 0, ERROR_ME, 0) < 0)
	    return 1;
	}
    }
  return 0;
}


/* Callers should GCPRO, since this may call eval */
static int
ignore_completion_p (Lisp_Object completion_string,
                     Lisp_Object pred, Lisp_Object completion)
{
  if (regexp_ignore_completion_p (0, completion_string, 0, -1))
    return 1;

  /* Ignore this element if there is a predicate
     and the predicate doesn't like it. */
  if (!NILP (pred))
  {
    Lisp_Object tem;
    if (EQ (pred, Qcommandp))
      tem = Fcommandp (completion);
    else
      tem = call1 (pred, completion);
    if (NILP (tem))
      return 1;
  }
  return 0;
}


/* #### Maybe we should allow COLLECTION to be a hash table.
   It is wrong for the use of obarrays to be better-rewarded than the
   use of hash tables.  By better-rewarded I mean that you can pass an
   obarray to all of the completion functions, whereas you can't do
   anything like that with a hash table.

   To do so, there should probably be a
   map_obarray_or_alist_or_hash_table function which would be used by
   both Ftry_completion and Fall_completions.  [[ But would the
   additional funcalls slow things down? ]] Seriously doubtful. --ben */

DEFUN ("try-completion", Ftry_completion, 2, 3, 0, /*
Return common substring of all completions of STRING in COLLECTION.
COLLECTION must be an alist, an obarray, or a function.
Each string in COLLECTION is tested to see if it begins with STRING.
All that match are compared together; the longest initial sequence
common to all matches is returned as a string.  If there is no match
at all, nil is returned.  For an exact match, t is returned.

If COLLECTION is an alist, the cars of the elements of the alist
\(which must be strings) form the set of possible completions.

If COLLECTION is an obarray, the names of all symbols in the obarray
are the possible completions.

If COLLECTION is a function, it is called with three arguments: the
values STRING, PREDICATE and nil.  Whatever it returns becomes the
value of `try-completion'.

If optional third argument PREDICATE is non-nil, it is used to test
each possible match.  The match is a candidate only if PREDICATE
returns non-nil.  The argument given to PREDICATE is the alist element
or the symbol from the obarray.
*/
       (string, collection, predicate))
{
  /* This function can GC */
  Lisp_Object bestmatch, tail;
  Charcount bestmatchsize = 0;
  int list;
  int indice = 0;
  int matchcount = 0;
  int obsize;
  Lisp_Object bucket;
  Charcount slength, blength;

  CHECK_STRING (string);

  if (CONSP (collection))
    {
      Lisp_Object tem = XCAR (collection);
      if (SYMBOLP (tem))	/* lambda, autoload, etc.  Emacs-lisp sucks */
	return call3 (collection, string, predicate, Qnil);
      else
	list = 1;
    }
  else if (VECTORP (collection))
    list = 0;
  else if (NILP (collection))
    list = 1;
  else
    return call3 (collection, string, predicate, Qnil);

  bestmatch = Qnil;
  blength = 0;
  slength = string_char_length (string);

  /* If COLLECTION is not a list, set TAIL just for gc pro.  */
  tail = collection;
  if (!list)
    {
      obsize = XVECTOR_LENGTH (collection);
      bucket = XVECTOR_DATA (collection)[indice];
    }
  else /* warning suppression */
    {
      obsize = 0;
      bucket = Qnil;
    }

  while (1)
    {
      /* Get the next element of the alist or obarray. */
      /* Exit the loop if the elements are all used up. */
      /* elt gets the alist element or symbol.
	 eltstring gets the name to check as a completion. */
      Lisp_Object elt;
      Lisp_Object eltstring;

      if (list)
	{
	  if (NILP (tail))
	    break;
	  elt = Fcar (tail);
	  eltstring = Fcar (elt);
	  tail = Fcdr (tail);
	}
      else
	{
	  if (!ZEROP (bucket))
	    {
              Lisp_Symbol *next;
	      if (!SYMBOLP (bucket))
		{
		  invalid_argument ("Bad obarray passed to try-completions",
				    bucket);
		}
	      next = symbol_next (XSYMBOL (bucket));
	      elt = bucket;
	      eltstring = Fsymbol_name (elt);
              if (next)
		bucket = wrap_symbol (next);
	      else
		bucket = Qzero;
	    }
	  else if (++indice >= obsize)
	    break;
	  else
	    {
	      bucket = XVECTOR_DATA (collection)[indice];
	      continue;
	    }
	}

      /* Is this element a possible completion? */

      if (STRINGP (eltstring))
	{
	  Charcount eltlength = string_char_length (eltstring);
	  if (slength <= eltlength
	      && (0 > scmp (XSTRING_DATA (eltstring),
                            XSTRING_DATA (string),
                            slength)))
	    {
              {
                struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
                int loser;
                GCPRO4 (tail, string, eltstring, bestmatch);
                loser = ignore_completion_p (eltstring, predicate, elt);
                UNGCPRO;
                if (loser)      /* reject this one */
                  continue;
              }

	      /* Update computation of how much all possible
		 completions match */

	      matchcount++;
	      if (NILP (bestmatch))
		{
		  bestmatch = eltstring;
                  blength = eltlength;
		  bestmatchsize = eltlength;
		}
	      else
		{
		  Charcount compare = min (bestmatchsize, eltlength);
		  Charcount matchsize =
		    scmp (XSTRING_DATA (bestmatch),
			  XSTRING_DATA (eltstring),
			  compare);
		  if (matchsize < 0)
		    matchsize = compare;
		  if (completion_ignore_case)
		    {
		      /* If this is an exact match except for case,
			 use it as the best match rather than one that is not
			 an exact match.  This way, we get the case pattern
			 of the actual match.  */
		      if ((matchsize == eltlength
			   && matchsize < blength)
			  ||
			  /* If there is more than one exact match ignoring
			     case, and one of them is exact including case,
			     prefer that one.  */
			  /* If there is no exact match ignoring case,
			     prefer a match that does not change the case
			     of the input.  */
			  ((matchsize == eltlength)
			   ==
			   (matchsize == blength)
			   && 0 > scmp_1 (XSTRING_DATA (eltstring),
					  XSTRING_DATA (string),
					  slength, 0)
			   && 0 <= scmp_1 (XSTRING_DATA (bestmatch),
					   XSTRING_DATA (string),
					   slength, 0)))
                      {
			bestmatch = eltstring;
                        blength = eltlength;
                      }
		    }
		  bestmatchsize = matchsize;
		}
	    }
	}
    }

  if (NILP (bestmatch))
    return Qnil;		/* No completions found */
  /* If we are ignoring case, and there is no exact match,
     and no additional text was supplied,
     don't change the case of what the user typed.  */
  if (completion_ignore_case
      && bestmatchsize == slength
      && blength > bestmatchsize)
    return string;

  /* Return t if the supplied string is an exact match (counting case);
     it does not require any change to be made.  */
  if (matchcount == 1
      && bestmatchsize == slength
      && 0 > scmp_1 (XSTRING_DATA (bestmatch),
		     XSTRING_DATA (string),
		     bestmatchsize, 0))
    return Qt;

  /* Else extract the part in which all completions agree */
  return Fsubstring (bestmatch, Qzero, make_int (bestmatchsize));
}


DEFUN ("all-completions", Fall_completions, 2, 3, 0, /*
Search for partial matches to STRING in COLLECTION.
COLLECTION must be an alist, an obarray, or a function.
Each string in COLLECTION is tested to see if it begins with STRING.
The value is a list of all the strings from COLLECTION that match.

If COLLECTION is an alist, the cars of the elements of the alist
\(which must be strings) form the set of possible completions.

If COLLECTION is an obarray, the names of all symbols in the obarray
are the possible completions.

If COLLECTION is a function, it is called with three arguments: the
values STRING, PREDICATE and t.  Whatever it returns becomes the
value of `all-completions'.

If optional third argument PREDICATE is non-nil, it is used to test
each possible match.  The match is a candidate only if PREDICATE
returns non-nil.  The argument given to PREDICATE is the alist element
or the symbol from the obarray.
*/
       (string, collection, predicate))
{
  /* This function can GC */
  Lisp_Object tail;
  Lisp_Object allmatches;
  int list;
  int indice = 0;
  int obsize;
  Lisp_Object bucket;
  Charcount slength;

  CHECK_STRING (string);

  if (CONSP (collection))
    {
      Lisp_Object tem = XCAR (collection);
      if (SYMBOLP (tem))	/* lambda, autoload, etc.  Emacs-lisp sucks */
	return call3 (collection, string, predicate, Qt);
      else
	list = 1;
    }
  else if (VECTORP (collection))
    list = 0;
  else if (NILP (collection))
    list = 1;
  else
    return call3 (collection, string, predicate, Qt);

  allmatches = Qnil;
  slength = string_char_length (string);

  /* If COLLECTION is not a list, set TAIL just for gc pro.  */
  tail = collection;
  if (!list)
    {
      obsize = XVECTOR_LENGTH (collection);
      bucket = XVECTOR_DATA (collection)[indice];
    }
  else /* warning suppression */
    {
      obsize = 0;
      bucket = Qnil;
    }

  while (1)
    {
      /* Get the next element of the alist or obarray. */
      /* Exit the loop if the elements are all used up. */
      /* elt gets the alist element or symbol.
	 eltstring gets the name to check as a completion. */
      Lisp_Object elt;
      Lisp_Object eltstring;

      if (list)
	{
	  if (NILP (tail))
	    break;
	  elt = Fcar (tail);
	  eltstring = Fcar (elt);
	  tail = Fcdr (tail);
	}
      else
	{
	  if (!ZEROP (bucket))
	    {
              Lisp_Symbol *next = symbol_next (XSYMBOL (bucket));
	      elt = bucket;
	      eltstring = Fsymbol_name (elt);
              if (next)
		bucket = wrap_symbol (next);
	      else
		bucket = Qzero;
            }
	  else if (++indice >= obsize)
	    break;
	  else
	    {
	      bucket = XVECTOR_DATA (collection)[indice];
	      continue;
	    }
	}

      /* Is this element a possible completion? */

      if (STRINGP (eltstring)
          && (slength <= string_char_length (eltstring))
          /* Reject alternatives that start with space
	     unless the input starts with space.  */
	  && ((string_char_length (string) > 0 &&
	       string_emchar (string, 0) == ' ')
	      || string_emchar (eltstring, 0) != ' ')
	  && (0 > scmp (XSTRING_DATA (eltstring),
                        XSTRING_DATA (string),
                        slength)))
	{
	  /* Yes.  Now check whether predicate likes it. */
          struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
          int loser;
          GCPRO4 (tail, eltstring, allmatches, string);
          loser = ignore_completion_p (eltstring, predicate, elt);
          UNGCPRO;
          if (!loser)
            /* Ok => put it on the list. */
            allmatches = Fcons (eltstring, allmatches);
        }
    }

  return Fnreverse (allmatches);
}

/* Useless FSFmacs functions */
/* More than useless.  I've nuked minibuf_prompt_width so they won't
   function at all in XEmacs at the moment.  They are used to
   implement some braindamage in FSF which we aren't including. --cet */

#if 0
DEFUN ("minibuffer-prompt", Fminibuffer_prompt, 0, 0, 0, /*
Return the prompt string of the currently-active minibuffer.
If no minibuffer is active, return nil.
*/
	 ())
{
  return Fcopy_sequence (Vminibuf_prompt);
}

DEFUN ("minibuffer-prompt-width", Fminibuffer_prompt_width, 0, 0, 0, /*
Return the display width of the minibuffer prompt.
*/
	 ())
{
  return make_int (minibuf_prompt_width);
}
#endif /* 0 */


/************************************************************************/
/*                              echo area                               */
/************************************************************************/

extern int stdout_needs_newline;

static Lisp_Object
clear_echo_area_internal (struct frame *f, Lisp_Object label, int from_print,
			  int no_restore)
{
  /* This function can call lisp */
  if (!NILP (Ffboundp (Qclear_message)))
    {
      Lisp_Object frame = wrap_frame (f);

      return call4 (Qclear_message, label, frame, from_print ? Qt : Qnil,
		    no_restore ? Qt : Qnil);
    }
  else
    {
      stderr_out ("\n");
      return Qnil;
    }
}

Lisp_Object
clear_echo_area (struct frame *f, Lisp_Object label, int no_restore)
{
  /* This function can call lisp */
  return clear_echo_area_internal (f, label, 0, no_restore);
}

Lisp_Object
clear_echo_area_from_print (struct frame *f, Lisp_Object label, int no_restore)
{
  /* This function can call lisp */
  return clear_echo_area_internal (f, label, 1, no_restore);
}

void
echo_area_append (struct frame *f, const Intbyte *nonreloc, Lisp_Object reloc,
		  Bytecount offset, Bytecount length,
		  Lisp_Object label)
{
  /* This function can call lisp */
  Lisp_Object obj;
  struct gcpro gcpro1;
  Lisp_Object frame;

  /* There is an inlining bug in egcs-20000131 c++ that can be worked
     around as follows:  */
#if defined (__GNUC__) && defined (__cplusplus)
  alloca (4);
#endif

  /* some callers pass in a null string as a way of clearing the echo area.
     check for length == 0 now; if this case, neither nonreloc nor reloc
     may be valid.  */
  if (length == 0)
    return;

  fixup_internal_substring (nonreloc, reloc, offset, &length);

  /* also check it here, in case the string was really blank. */
  if (length == 0)
    return;

  if (!NILP (Ffboundp (Qappend_message)))
    {
      if (STRINGP (reloc) && offset == 0 && length == XSTRING_LENGTH (reloc))
	obj = reloc;
      else
	{
	  if (STRINGP (reloc))
	    nonreloc = XSTRING_DATA (reloc);
	  obj = make_string (nonreloc + offset, length);
	}

      frame = wrap_frame (f);
      GCPRO1 (obj);
      call4 (Qappend_message, label, obj, frame,
	     EQ (label, Qprint) ? Qt : Qnil);
      UNGCPRO;
    }
  else
    {
      if (STRINGP (reloc))
	nonreloc = XSTRING_DATA (reloc);
      write_string_1 (Qexternal_debugging_output, nonreloc + offset, length);
    }
}

void
echo_area_message (struct frame *f, const Intbyte *nonreloc,
		   Lisp_Object reloc, Bytecount offset, Bytecount length,
		   Lisp_Object label)
{
  /* This function can call lisp */
  clear_echo_area (f, label, 1);
  echo_area_append (f, nonreloc, reloc, offset, length, label);
}

int
echo_area_active (struct frame *f)
{
  /* By definition, the echo area is active if the echo-area buffer
     is not empty.  No need to call Lisp code. (Anyway, this function
     is called from redisplay.) */
  struct buffer *echo_buffer = XBUFFER (Vecho_area_buffer);
  return BUF_BEGV (echo_buffer) != BUF_ZV (echo_buffer);
}

Lisp_Object
echo_area_status (struct frame *f)
{
  /* This function can call lisp */
  if (!NILP (Ffboundp (Qcurrent_message_label)))
    {
      Lisp_Object frame = wrap_frame (f);

      return call1 (Qcurrent_message_label, frame);
    }
  else
    return stdout_needs_newline ? Qmessage : Qnil;
}

Lisp_Object
echo_area_contents (struct frame *f)
{
  /* See above.  By definition, the contents of the echo-area buffer
     are the contents of the echo area. */
  return Fbuffer_substring (Qnil, Qnil, Vecho_area_buffer);
}

/* Dump an informative message to the echo area.  This function takes a
   string in internal format. */
void
message_internal (const Intbyte *nonreloc, Lisp_Object reloc,
		  Bytecount offset, Bytecount length)
{
  /* This function can call lisp  */
  if (NILP (Vexecuting_macro))
    echo_area_message (selected_frame (), nonreloc, reloc, offset, length,
		       Qmessage);
}

void
message_append_internal (const Intbyte *nonreloc, Lisp_Object reloc,
			 Bytecount offset, Bytecount length)
{
  /* This function can call lisp  */
  if (NILP (Vexecuting_macro))
    echo_area_append (selected_frame (), nonreloc, reloc, offset, length,
		      Qmessage);
}

/* The next three functions are interfaces to message_internal() that
   take strings in external format.  message() does I18N3 translating
   on the format string; message_no_translate() does not. */

static void
message_1 (const CIntbyte *fmt, va_list args)
{
  /* This function can call lisp */
  if (fmt)
    {
      struct gcpro gcpro1;
      /* message_internal() might GC, e.g. if there are after-change-hooks
	 on the echo area buffer */
      Lisp_Object obj = emacs_vsprintf_string (fmt, args);
      GCPRO1 (obj);
      message_internal (0, obj, 0, -1);
      UNGCPRO;
    }
  else
    message_internal (0, Qnil, 0, 0);
}

static void
message_append_1 (const CIntbyte *fmt, va_list args)
{
  /* This function can call lisp */
  if (fmt)
    {
      struct gcpro gcpro1;
      /* message_internal() might GC, e.g. if there are after-change-hooks
	 on the echo area buffer */
      Lisp_Object obj = emacs_vsprintf_string (fmt, args);
      GCPRO1 (obj);
      message_append_internal (0, obj, 0, -1);
      UNGCPRO;
    }
  else
    message_append_internal (0, Qnil, 0, 0);
}

void
clear_message (void)
{
  /* This function can call lisp */
  message_internal (0, Qnil, 0, 0);
}

void
message (const char *fmt, ...)
{
  /* This function can call lisp */
  /* I think it's OK to pass the data of Lisp strings as arguments to
     this function.  No GC'ing will occur until the data has already
     been copied. */
  va_list args;

  va_start (args, fmt);
  if (fmt)
    fmt = GETTEXT (fmt);
  message_1 (fmt, args);
  va_end (args);
}

void
message_append (const char *fmt, ...)
{
  /* This function can call lisp */
  va_list args;

  va_start (args, fmt);
  if (fmt)
    fmt = GETTEXT (fmt);
  message_append_1 (fmt, args);
  va_end (args);
}

void
message_no_translate (const char *fmt, ...)
{
  /* This function can call lisp */
  /* I think it's OK to pass the data of Lisp strings as arguments to
     this function.  No GC'ing will occur until the data has already
     been copied. */
  va_list args;

  va_start (args, fmt);
  message_1 (fmt, args);
  va_end (args);
}


/************************************************************************/
/*                            initialization                            */
/************************************************************************/

void
syms_of_minibuf (void)
{
  DEFSYMBOL (Qminibuffer_setup_hook);

  DEFSYMBOL (Qcompletion_ignore_case);

  DEFSUBR (Fminibuffer_depth);
#if 0
  DEFSUBR (Fminibuffer_prompt);
  DEFSUBR (Fminibuffer_prompt_width);
#endif
  DEFSUBR (Fset_minibuffer_preprompt);
  DEFSUBR (Fread_minibuffer_internal);

  DEFSUBR (Ftry_completion);
  DEFSUBR (Fall_completions);

  DEFSYMBOL (Qappend_message);
  DEFSYMBOL (Qclear_message);
  DEFSYMBOL (Qdisplay_message);
  DEFSYMBOL (Qcurrent_message_label);
}

void
reinit_vars_of_minibuf (void)
{
  minibuf_level = 0;
}

void
vars_of_minibuf (void)
{
  reinit_vars_of_minibuf ();

  staticpro (&Vminibuf_prompt);
  Vminibuf_prompt = Qnil;

  /* Added by Jareth Hein (jhod@po.iijnet.or.jp) for input system support */
  staticpro (&Vminibuf_preprompt);
  Vminibuf_preprompt = Qnil;

  DEFVAR_LISP ("minibuffer-setup-hook", &Vminibuffer_setup_hook /*
Normal hook run just after entry to minibuffer.
*/ );
  Vminibuffer_setup_hook = Qnil;

  DEFVAR_BOOL ("completion-ignore-case", &completion_ignore_case /*
Non-nil means don't consider case significant in completion.
*/ );
  completion_ignore_case = 0;

  DEFVAR_LISP ("completion-regexp-list", &Vcompletion_regexp_list /*
List of regexps that should restrict possible completions.
Each completion has to match all regexps in this list.
*/ );
  Vcompletion_regexp_list = Qnil;
}

void
reinit_complex_vars_of_minibuf (void)
{
  /* This function can GC */
#ifdef I18N3
  /* #### This needs to be fixed up so that the gettext() gets called
     at runtime instead of at load time. */
#endif
  Vminibuffer_zero
    = Fget_buffer_create
      (build_string (DEFER_GETTEXT (" *Minibuf-0*")));
  Vecho_area_buffer
    = Fget_buffer_create
      (build_string (DEFER_GETTEXT (" *Echo Area*")));
}

void
complex_vars_of_minibuf (void)
{
  reinit_complex_vars_of_minibuf ();
}