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[bpt/emacs.git] / src / minibuf.c

/* Minibuffer input and completion.
   Copyright (C) 1985, 1986, 1992 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include "config.h"
#include "lisp.h"
#include "commands.h"
#include "buffer.h"
#include "dispextern.h"
#include "frame.h"
#include "window.h"
#include "syntax.h"

#define min(a, b) ((a) < (b) ? (a) : (b))

/* List of buffers for use as minibuffers.
  The first element of the list is used for the outermost minibuffer invocation,
  the next element is used for a recursive minibuffer invocation, etc.
  The list is extended at the end as deeped minibuffer recursions are encountered. */
Lisp_Object Vminibuffer_list;

struct minibuf_save_data
  {
    char *prompt;
    int prompt_width;
    Lisp_Object help_form;
    Lisp_Object current_prefix_arg;
  };

int minibuf_save_vector_size;
struct minibuf_save_data *minibuf_save_vector;

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

/* Nonzero means display completion help for invalid input */
int auto_help;

/* Fread_minibuffer leaves the input, as a string, here */
Lisp_Object last_minibuf_string;

/* Nonzero means let functions called when within a minibuffer 
   invoke recursive minibuffers (to read arguments, or whatever) */
int enable_recursive_minibuffers;

/* help-form is bound to this while in the minibuffer.  */

Lisp_Object Vminibuffer_help_form;

/* Nonzero means completion ignores case.  */

int completion_ignore_case;

/* If last completion attempt reported "Complete but not unique"
   then this is the string completed then; otherwise this is nil.  */

static Lisp_Object last_exact_completion;

Lisp_Object Quser_variable_p;

\f
/* Actual minibuffer invocation. */

void read_minibuf_unwind ();
Lisp_Object get_minibuffer ();
Lisp_Object read_minibuf ();

Lisp_Object
read_minibuf (map, initial, prompt, backup_n, expflag)
     Lisp_Object map;
     Lisp_Object initial;
     Lisp_Object prompt;
     Lisp_Object backup_n;
     int expflag;
{
  register Lisp_Object val;
  int count = specpdl_ptr - specpdl;
  Lisp_Object mini_frame = WINDOW_FRAME (XWINDOW (minibuf_window));
  struct gcpro gcpro1, gcpro2;

  if (XTYPE (prompt) != Lisp_String)
    prompt = build_string ("");

  /* Emacs in -batch mode calls minibuffer: print the prompt.  */
  if (noninteractive && XTYPE (prompt) == Lisp_String)
    printf ("%s", XSTRING (prompt)->data);

  if (!enable_recursive_minibuffers
      && minibuf_level > 0
      && (EQ (selected_window, minibuf_window)))
#if 0
	  || selected_frame != XFRAME (WINDOW_FRAME (XWINDOW (minibuf_window)))
#endif
    error ("Command attempted to use minibuffer while in minibuffer");

  if (minibuf_level == minibuf_save_vector_size)
    minibuf_save_vector =
     (struct minibuf_save_data *)
       xrealloc (minibuf_save_vector,
		 (minibuf_save_vector_size *= 2)
		 * sizeof (struct minibuf_save_data)); 
  minibuf_save_vector[minibuf_level].prompt = minibuf_prompt;
  minibuf_save_vector[minibuf_level].prompt_width = minibuf_prompt_width;
  minibuf_prompt_width = 0;
  /* >> Why is this done this way rather than binding these variables? */
  minibuf_save_vector[minibuf_level].help_form = Vhelp_form;
  minibuf_save_vector[minibuf_level].current_prefix_arg = Vcurrent_prefix_arg;
  GCPRO2 (minibuf_save_vector[minibuf_level].help_form,
	  minibuf_save_vector[minibuf_level].current_prefix_arg);

  record_unwind_protect (Fset_window_configuration,
			 Fcurrent_window_configuration (Qnil));

  /* If the minibuffer window is on a different frame, save that
     frame's configuration too.  */
  if (XFRAME (mini_frame) != selected_frame)
    {
      record_unwind_protect (Fset_window_configuration,
			     Fcurrent_window_configuration (mini_frame));
    }

  val = current_buffer->directory;
  Fset_buffer (get_minibuffer (minibuf_level));
  current_buffer->directory = val;
  Fmake_local_variable (Qprint_escape_newlines);
  print_escape_newlines = 1;

#ifdef MULTI_FRAME
  /* If the minibuffer window is on another frame, shift this frame's
     focus to that window, and arrange to put it back later.  */
  if (XFRAME (WINDOW_FRAME (XWINDOW (minibuf_window)))
      != selected_frame)
    {
      record_unwind_protect (read_minibuf_unwind,
			     Fcons (Fselected_frame (),
				    FRAME_FOCUS_FRAME (selected_frame)));

      Fredirect_frame_focus (Fselected_frame (), mini_frame);
    }
  else
    record_unwind_protect (read_minibuf_unwind, Qnil);
#else
  record_unwind_protect (read_minibuf_unwind, Qnil);
#endif

  Vminibuf_scroll_window = selected_window;
  Fset_window_buffer (minibuf_window, Fcurrent_buffer ());
  Fselect_window (minibuf_window);
  XFASTINT (XWINDOW (minibuf_window)->hscroll) = 0;

  Ferase_buffer ();
  minibuf_level++;

  if (!NILP (initial))
    {
      Finsert (1, &initial);
      if (!NILP (backup_n) && XTYPE (backup_n) == Lisp_Int)
	Fforward_char (backup_n);
    }

  minibuf_prompt = (char *) alloca (XSTRING (prompt)->size + 1);
  bcopy (XSTRING (prompt)->data, minibuf_prompt, XSTRING (prompt)->size + 1);
  echo_area_glyphs = 0;

  Vhelp_form = Vminibuffer_help_form;
  current_buffer->keymap = map;

/* ??? MCC did redraw_screen here if switching screens.  */
  recursive_edit_1 ();

  /* If cursor is on the minibuffer line,
     show the user we have exited by putting it in column 0.  */
  if ((FRAME_CURSOR_Y (selected_frame)
       >= XFASTINT (XWINDOW (minibuf_window)->top))
      && !noninteractive)
    {
      FRAME_CURSOR_X (selected_frame) = 0;
      update_frame (selected_frame, 1, 1);
    }

  /* Make minibuffer contents into a string */
  val = make_buffer_string (1, Z);
  bcopy (GAP_END_ADDR, XSTRING (val)->data + GPT - BEG, Z - GPT);
  unbind_to (count, Qnil);	/* The appropriate frame will get selected
				   in set-window-configuration.  */

  UNGCPRO;

  /* VAL is the string of minibuffer text.  */

  last_minibuf_string = val;

  /* If Lisp form desired instead of string, parse it */
  if (expflag)
    val = Fread (val);

  return val;
}

/* Return a buffer to be used as the minibuffer at depth `depth'.
 depth = 0 is the lowest allowed argument, and that is the value
 used for nonrecursive minibuffer invocations */

Lisp_Object
get_minibuffer (depth)
     int depth;
{
  Lisp_Object tail, num, buf;
  char name[14];
  extern Lisp_Object nconc2 ();

  XFASTINT (num) = depth;
  tail = Fnthcdr (num, Vminibuffer_list);
  if (NILP (tail))
    {
      tail = Fcons (Qnil, Qnil);
      Vminibuffer_list = nconc2 (Vminibuffer_list, tail);
    }
  buf = Fcar (tail);
  if (NILP (buf) || NILP (XBUFFER (buf)->name))
    {
      sprintf (name, " *Minibuf-%d*", depth);
      buf = Fget_buffer_create (build_string (name));
      XCONS (tail)->car = buf;
    }
  else
    reset_buffer (XBUFFER (buf));
  return buf;
}

/* This function is called on exiting minibuffer, whether normally or not,
 and it restores the current window, buffer, etc. */

void
read_minibuf_unwind (data)
     Lisp_Object data;
{
  /* Erase the minibuffer we were using at this level.  */
  Fset_buffer (XWINDOW (minibuf_window)->buffer);

  /* Prevent error in erase-buffer.  */
  current_buffer->read_only = Qnil;
  Ferase_buffer ();

  /* If this was a recursive minibuffer,
     tie the minibuffer window back to the outer level minibuffer buffer */
  minibuf_level--;
  /* Make sure minibuffer window is erased, not ignored */
  windows_or_buffers_changed++;
  XFASTINT (XWINDOW (minibuf_window)->last_modified) = 0;

  /* Restore prompt from outer minibuffer */
  minibuf_prompt = minibuf_save_vector[minibuf_level].prompt;
  minibuf_prompt_width = minibuf_save_vector[minibuf_level].prompt_width;
  Vhelp_form = minibuf_save_vector[minibuf_level].help_form;
  Vcurrent_prefix_arg = minibuf_save_vector[minibuf_level].current_prefix_arg;

#ifdef MULTI_FRAME
  /* Redirect the focus of the frame that called the minibuffer.  */
  if (CONSP (data))
    Fredirect_frame_focus (XCONS (data)->car, XCONS (data)->cdr);
#endif
}
\f
DEFUN ("read-from-minibuffer", Fread_from_minibuffer, Sread_from_minibuffer, 1, 5, 0,
  "Read a string from the minibuffer, prompting with string PROMPT.\n\
If optional second arg INITIAL-CONTENTS is non-nil, it is a string\n\
  to be inserted into the minibuffer before reading input.\n\
Third arg KEYMAP is a keymap to use whilst reading;\n\
  if omitted or nil, the default is `minibuffer-local-map'.\n\
If fourth arg READ is non-nil, then interpret the result as a lisp object\n\
  and return that object:\n\
  in other words, do `(car (read-from-string INPUT-STRING))'\n\
Fifth arg POSITION, if non-nil, is where to put point\n\
  in the minibuffer after inserting INITIAL-CONTENTS.")
  (prompt, initial_input, keymap, read, position)
     Lisp_Object prompt, initial_input, keymap, read, position;
{
  int pos = 0;

  CHECK_STRING (prompt, 0);
  if (!NILP (initial_input))
    {
      CHECK_STRING (initial_input, 1);
      if (!NILP (position))
	{
	  CHECK_NUMBER (position, 0);
	  /* Convert to distance from end of input.  */
	  pos = XINT (position) - 1 - XSTRING (initial_input)->size;
	}
    }

  if (NILP (keymap))
    keymap = Vminibuffer_local_map;
  else
    keymap = get_keymap (keymap,2);
  return read_minibuf (keymap, initial_input, prompt,
		       pos, !NILP (read));
}

DEFUN ("read-minibuffer", Fread_minibuffer, Sread_minibuffer, 1, 2, 0,
  "Return a Lisp object read using the minibuffer.\n\
Prompt with PROMPT.  If non-nil, optional second arg INITIAL-CONTENTS\n\
is a string to insert in the minibuffer before reading.")
  (prompt, initial_contents)
     Lisp_Object prompt, initial_contents;
{
  CHECK_STRING (prompt, 0);
  if (!NILP (initial_contents))
    CHECK_STRING (initial_contents, 1)
  return read_minibuf (Vminibuffer_local_map, initial_contents, prompt, Qnil, 1);
}

DEFUN ("eval-minibuffer", Feval_minibuffer, Seval_minibuffer, 1, 2, 0,
  "Return value of Lisp expression read using the minibuffer.\n\
Prompt with PROMPT.  If non-nil, optional second arg INITIAL-CONTENTS\n\
is a string to insert in the minibuffer before reading.")
  (prompt, initial_contents)
     Lisp_Object prompt, initial_contents;
{
  return Feval (Fread_minibuffer (prompt, initial_contents));
}

/* Functions that use the minibuffer to read various things. */

DEFUN ("read-string", Fread_string, Sread_string, 1, 2, 0,
  "Read a string from the minibuffer, prompting with string PROMPT.\n\
If non-nil second arg INITIAL-INPUT is a string to insert before reading.")
  (prompt, initial_input)
     Lisp_Object prompt, initial_input;
{
  return Fread_from_minibuffer (prompt, initial_input, Qnil, Qnil, Qnil);
}

DEFUN ("read-no-blanks-input", Fread_no_blanks_input, Sread_no_blanks_input, 2, 2, 0,
  "Args PROMPT and INIT, strings.  Read a string from the terminal, not allowing blanks.\n\
Prompt with PROMPT, and provide INIT as an initial value of the input string.")
  (prompt, init)
     Lisp_Object prompt, init;
{
  CHECK_STRING (prompt, 0);
  if (! NILP (init))
    CHECK_STRING (init, 1);

  return read_minibuf (Vminibuffer_local_ns_map, init, prompt, Qnil, 0);
}

DEFUN ("read-command", Fread_command, Sread_command, 1, 1, 0,
  "One arg PROMPT, a string.  Read the name of a command and return as a symbol.\n\
Prompts with PROMPT.")
  (prompt)
     Lisp_Object prompt;
{
  return Fintern (Fcompleting_read (prompt, Vobarray, Qcommandp, Qt, Qnil, Qnil),
		  Qnil);
}

#ifdef NOTDEF
DEFUN ("read-function", Fread_function, Sread_function, 1, 1, 0,
  "One arg PROMPT, a string.  Read the name of a function and return as a symbol.\n\
Prompts with PROMPT.")
  (prompt)
     Lisp_Object prompt;
{
  return Fintern (Fcompleting_read (prompt, Vobarray, Qfboundp, Qt, Qnil, Qnil),
		  Qnil);
}
#endif /* NOTDEF */

DEFUN ("read-variable", Fread_variable, Sread_variable, 1, 1, 0,
  "One arg PROMPT, a string.  Read the name of a user variable and return\n\
it as a symbol.  Prompts with PROMPT.\n\
A user variable is one whose documentation starts with a `*' character.")
  (prompt)
     Lisp_Object prompt;
{
  return Fintern (Fcompleting_read (prompt, Vobarray,
				    Quser_variable_p, Qt, Qnil, Qnil),
		  Qnil);
}

DEFUN ("read-buffer", Fread_buffer, Sread_buffer, 1, 3, 0,
  "One arg PROMPT, a string.  Read the name of a buffer and return as a string.\n\
Prompts with PROMPT.\n\
Optional second arg is value to return if user enters an empty line.\n\
If optional third arg REQUIRE-MATCH is non-nil, only existing buffer names are allowed.")
  (prompt, def, require_match)
     Lisp_Object prompt, def, require_match;
{
  Lisp_Object tem;
  Lisp_Object args[3];
  struct gcpro gcpro1;

  if (XTYPE (def) == Lisp_Buffer)
    def = XBUFFER (def)->name;
  if (!NILP (def))
    {
      args[0] = build_string ("%s(default %s) ");
      args[1] = prompt;
      args[2] = def;
      prompt = Fformat (3, args);
    }
  GCPRO1 (def);
  tem = Fcompleting_read (prompt, Vbuffer_alist, Qnil, require_match, Qnil, Qnil);
  UNGCPRO;
  if (XSTRING (tem)->size)
    return tem;
  return def;
}
\f
DEFUN ("try-completion", Ftry_completion, Stry_completion, 2, 3, 0,
  "Return common substring of all completions of STRING in ALIST.\n\
Each car of each element of ALIST is tested to see if it begins with STRING.\n\
All that match are compared together; the longest initial sequence\n\
common to all matches is returned as a string.\n\
If there is no match at all, nil is returned.\n\
For an exact match, t is returned.\n\
\n\
ALIST can be an obarray instead of an alist.\n\
Then the print names of all symbols in the obarray are the possible matches.\n\
\n\
ALIST can also be a function to do the completion itself.\n\
It receives three arguments: the values STRING, PREDICATE and nil.\n\
Whatever it returns becomes the value of `try-completion'.\n\
\n\
If optional third argument PREDICATE is non-nil,\n\
it is used to test each possible match.\n\
The match is a candidate only if PREDICATE returns non-nil.\n\
The argument given to PREDICATE is the alist element or the symbol from the obarray.")
  (string, alist, pred)
     Lisp_Object string, alist, pred;
{
  Lisp_Object bestmatch, tail, elt, eltstring;
  int bestmatchsize;
  int compare, matchsize;
  int list = CONSP (alist) || NILP (alist);
  int index, obsize;
  int matchcount = 0;
  Lisp_Object bucket, zero, end, tem;
  struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;

  CHECK_STRING (string, 0);
  if (!list && XTYPE (alist) != Lisp_Vector)
    return call3 (alist, string, pred, Qnil);

  bestmatch = Qnil;

  /* If ALIST is not a list, set TAIL just for gc pro.  */
  tail = alist;
  if (! list)
    {
      index = 0;
      obsize = XVECTOR (alist)->size;
      bucket = XVECTOR (alist)->contents[index];
    }

  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. */

      if (list)
	{
	  if (NILP (tail))
	    break;
	  elt = Fcar (tail);
	  eltstring = Fcar (elt);
	  tail = Fcdr (tail);
	}
      else
	{
	  if (XFASTINT (bucket) != 0)
	    {
	      elt = bucket;
	      eltstring = Fsymbol_name (elt);
	      if (XSYMBOL (bucket)->next)
		XSETSYMBOL (bucket, XSYMBOL (bucket)->next);
	      else
		XFASTINT (bucket) = 0;
	    }
	  else if (++index >= obsize)
	    break;
	  else
	    {
	      bucket = XVECTOR (alist)->contents[index];
	      continue;
	    }
	}

      /* Is this element a possible completion? */

      if (XTYPE (eltstring) == Lisp_String &&
	  XSTRING (string)->size <= XSTRING (eltstring)->size &&
	  0 > scmp (XSTRING (eltstring)->data, XSTRING (string)->data,
		    XSTRING (string)->size))
	{
	  /* Yes. */
	  /* Ignore this element if there is a predicate
	     and the predicate doesn't like it. */

	  if (!NILP (pred))
	    {
	      if (EQ (pred, Qcommandp))
		tem = Fcommandp (elt);
	      else
		{
		  GCPRO4 (tail, string, eltstring, bestmatch);
		  tem = call1 (pred, elt);
		  UNGCPRO;
		}
	      if (NILP (tem)) continue;
	    }

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

	  matchcount++;
	  if (NILP (bestmatch))
	    bestmatch = eltstring, bestmatchsize = XSTRING (eltstring)->size;
	  else
	    {
	      compare = min (bestmatchsize, XSTRING (eltstring)->size);
	      matchsize = scmp (XSTRING (bestmatch)->data,
				XSTRING (eltstring)->data,
				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 == XSTRING (eltstring)->size
		       && matchsize < XSTRING (bestmatch)->size)
		      ||
		      /* 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 == XSTRING (eltstring)->size)
		       ==
		       (matchsize == XSTRING (bestmatch)->size)
		       && !bcmp (XSTRING (eltstring)->data,
				 XSTRING (string)->data, XSTRING (string)->size)
		       && bcmp (XSTRING (bestmatch)->data,
				XSTRING (string)->data, XSTRING (string)->size)))
		    bestmatch = eltstring;
		}
	      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 == XSTRING (string)->size
      && XSTRING (bestmatch)->size > 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 == XSTRING (string)->size
      && !bcmp (XSTRING (bestmatch)->data, XSTRING (string)->data,
		bestmatchsize))
    return Qt;

  XFASTINT (zero) = 0;		/* Else extract the part in which */
  XFASTINT (end) = bestmatchsize;	     /* all completions agree */
  return Fsubstring (bestmatch, zero, end);
}

/* 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.  */

scmp (s1, s2, len)
     register char *s1, *s2;
     int len;
{
  register int l = len;

  if (completion_ignore_case)
    {
      while (l && DOWNCASE (*s1++) == DOWNCASE (*s2++))
	l--;
    }
  else
    {
      while (l && *s1++ == *s2++)
	l--;
    }
  if (l == 0)
    return -1;
  else return len - l;
}
\f
DEFUN ("all-completions", Fall_completions, Sall_completions, 2, 3, 0,
  "Search for partial matches to STRING in ALIST.\n\
Each car of each element of ALIST is tested to see if it begins with STRING.\n\
The value is a list of all the strings from ALIST that match.\n\
ALIST can be an obarray instead of an alist.\n\
Then the print names of all symbols in the obarray are the possible matches.\n\
\n\
ALIST can also be a function to do the completion itself.\n\
It receives three arguments: the values STRING, PREDICATE and t.\n\
Whatever it returns becomes the value of `all-completion'.\n\
\n\
If optional third argument PREDICATE is non-nil,\n\
it is used to test each possible match.\n\
The match is a candidate only if PREDICATE returns non-nil.\n\
The argument given to PREDICATE is the alist element or the symbol from the obarray.")
  (string, alist, pred)
     Lisp_Object string, alist, pred;
{
  Lisp_Object tail, elt, eltstring;
  Lisp_Object allmatches;
  int list = CONSP (alist) || NILP (alist);
  int index, obsize;
  Lisp_Object bucket, tem;
  struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;

  CHECK_STRING (string, 0);
  if (!list && XTYPE (alist) != Lisp_Vector)
    {
      return call3 (alist, string, pred, Qt);
    }
  allmatches = Qnil;

  /* If ALIST is not a list, set TAIL just for gc pro.  */
  tail = alist;
  if (! list)
    {
      index = 0;
      obsize = XVECTOR (alist)->size;
      bucket = XVECTOR (alist)->contents[index];
    }

  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. */

      if (list)
	{
	  if (NILP (tail))
	    break;
	  elt = Fcar (tail);
	  eltstring = Fcar (elt);
	  tail = Fcdr (tail);
	}
      else
	{
	  if (XFASTINT (bucket) != 0)
	    {
	      elt = bucket;
	      eltstring = Fsymbol_name (elt);
	      if (XSYMBOL (bucket)->next)
		XSETSYMBOL (bucket, XSYMBOL (bucket)->next);
	      else
		XFASTINT (bucket) = 0;
	    }
	  else if (++index >= obsize)
	    break;
	  else
	    {
	      bucket = XVECTOR (alist)->contents[index];
	      continue;
	    }
	}

      /* Is this element a possible completion? */

      if (XTYPE (eltstring) == Lisp_String &&
	  XSTRING (string)->size <= XSTRING (eltstring)->size &&
	  XSTRING (eltstring)->data[0] != ' ' &&
	  0 > scmp (XSTRING (eltstring)->data, XSTRING (string)->data,
		    XSTRING (string)->size))
	{
	  /* Yes. */
	  /* Ignore this element if there is a predicate
	     and the predicate doesn't like it. */

	  if (!NILP (pred))
	    {
	      if (EQ (pred, Qcommandp))
		tem = Fcommandp (elt);
	      else
		{
		  GCPRO4 (tail, eltstring, allmatches, string);
		  tem = call1 (pred, elt);
		  UNGCPRO;
		}
	      if (NILP (tem)) continue;
	    }
	  /* Ok => put it on the list. */
	  allmatches = Fcons (eltstring, allmatches);
	}
    }

  return Fnreverse (allmatches);
}
\f
Lisp_Object Vminibuffer_completion_table, Qminibuffer_completion_table;
Lisp_Object Vminibuffer_completion_predicate, Qminibuffer_completion_predicate;
Lisp_Object Vminibuffer_completion_confirm, Qminibuffer_completion_confirm;

DEFUN ("completing-read", Fcompleting_read, Scompleting_read, 2, 6, 0,
  "Read a string in the minibuffer, with completion.\n\
Args: PROMPT, TABLE, PREDICATE, REQUIRE-MATCH, INITIAL-INPUT, BACKUP-N.\n\
PROMPT is a string to prompt with; normally it ends in a colon and a space.\n\
TABLE is an alist whose elements' cars are strings, or an obarray.\n\
PREDICATE limits completion to a subset of TABLE.\n\
See `try-completion' for more details on completion, TABLE, and PREDICATE.\n\
If REQUIRE-MATCH is non-nil, the user is not allowed to exit unless\n\
 the input is (or completes to) an element of TABLE.\n\
 If it is also not t, Return does not exit if it does non-null completion.\n\
If INITIAL-INPUT is non-nil, insert it in the minibuffer initially.\n\
Case is ignored if ambient value of `completion-ignore-case' is non-nil.\n\
If BACKUP-N is specified, point should be placed that many spaces from\n\
the end of the buffer.  This is useful when providing default values,\n\
because you can put point before the last component of a filename or any\n\
other component that is likely to be deleted.")
  (prompt, table, pred, require_match, init, backup_n)
     Lisp_Object prompt, table, pred, require_match, init, backup_n;
{
  Lisp_Object val;
  int count = specpdl_ptr - specpdl;
  specbind (Qminibuffer_completion_table, table);
  specbind (Qminibuffer_completion_predicate, pred);
  specbind (Qminibuffer_completion_confirm,
	    EQ (require_match, Qt) ? Qnil : Qt);
  last_exact_completion = Qnil;
  val = read_minibuf (NILP (require_match)
		      ? Vminibuffer_local_completion_map
		      : Vminibuffer_local_must_match_map,
		      init, prompt, backup_n, 0);
  return unbind_to (count, val);
}
\f
/* Temporarily display the string M at the end of the current
   minibuffer contents.  This is used to display things like
   "[No Match]" when the user requests a completion for a prefix
   that has no possible completions, and other quick, unobtrusive
   messages.  */

temp_echo_area_glyphs (m)
     char *m;
{
  /* It's not very modular to do things this way, but then it seems
     to me that the whole echo_area_glyphs thing is a hack anyway.  */
  extern char *previous_echo_glyphs;

  int osize = ZV;
  Lisp_Object oinhibit;
  oinhibit = Vinhibit_quit;

  /* Clear out any old echo-area message to make way for our new
     thing.  */
  echo_area_glyphs = previous_echo_glyphs = 0;

  SET_PT (osize);
  insert_string (m);
  SET_PT (osize);
  Vinhibit_quit = Qt;
  Fsit_for (make_number (2), Qnil, Qnil);
  del_range (point, ZV);
  if (!NILP (Vquit_flag))
    {
      Vquit_flag = Qnil;
      unread_command_char = Ctl ('g');
    }
  Vinhibit_quit = oinhibit;
}

Lisp_Object Fminibuffer_completion_help ();
Lisp_Object assoc_for_completion ();

/* returns:
 * 0 no possible completion
 * 1 was already an exact and unique completion
 * 3 was already an exact completion
 * 4 completed to an exact completion
 * 5 some completion happened
 * 6 no completion happened
 */
int
do_completion ()
{
  Lisp_Object completion, tem;
  int completedp;
  Lisp_Object last;

  completion = Ftry_completion (Fbuffer_string (), Vminibuffer_completion_table,
				Vminibuffer_completion_predicate);
  last = last_exact_completion;
  last_exact_completion = Qnil;

  if (NILP (completion))
    {
      bitch_at_user ();
      temp_echo_area_glyphs (" [No match]");
      return 0;
    }

  if (EQ (completion, Qt))	/* exact and unique match */
    return 1;

  /* compiler bug */
  tem = Fstring_equal (completion, Fbuffer_string());
  if (completedp = NILP (tem))
    {
      Ferase_buffer ();		/* Some completion happened */
      Finsert (1, &completion);
    }

  /* It did find a match.  Do we match some possibility exactly now? */
  if (CONSP (Vminibuffer_completion_table)
      || NILP (Vminibuffer_completion_table))
    tem = assoc_for_completion (Fbuffer_string (),
				Vminibuffer_completion_table);
  else if (XTYPE (Vminibuffer_completion_table) == Lisp_Vector)
    {
      /* the primitive used by Fintern_soft */
      extern Lisp_Object oblookup ();

      tem = Fbuffer_string ();
      /* Bypass intern-soft as that loses for nil */
      tem = oblookup (Vminibuffer_completion_table,
		      XSTRING (tem)->data, XSTRING (tem)->size);
      if (XTYPE (tem) != Lisp_Symbol)
	tem = Qnil;
      else if (!NILP (Vminibuffer_completion_predicate))
	tem = call1 (Vminibuffer_completion_predicate, tem);
      else
	tem = Qt;
    }
  else
    tem = call3 (Vminibuffer_completion_table,
		 Fbuffer_string (),
		 Vminibuffer_completion_predicate,
		 Qlambda);

  if (NILP (tem))
    { /* not an exact match */
      if (completedp)
	return 5;
      else if (auto_help)
	Fminibuffer_completion_help ();
      else
	temp_echo_area_glyphs (" [Next char not unique]");
      return 6;
    }
  else if (completedp)
    return 4;
  /* If the last exact completion and this one were the same,
     it means we've already given a "Complete but not unique"
     message and the user's hit TAB again, so now we give him help.  */
  last_exact_completion = completion;
  if (!NILP (last))
    {
      tem = Fbuffer_string ();
      if (!NILP (Fequal (tem, last)))
	Fminibuffer_completion_help ();
    }
  return 3;
}
  
/* Like assoc but assumes KEY is a string, and ignores case if appropriate.  */

Lisp_Object
assoc_for_completion (key, list)
     register Lisp_Object key;
     Lisp_Object list;
{
  register Lisp_Object tail;

  if (completion_ignore_case)
    key = Fupcase (key);

  for (tail = list; !NILP (tail); tail = Fcdr (tail))
    {
      register Lisp_Object elt, tem, thiscar;
      elt = Fcar (tail);
      if (!CONSP (elt)) continue;
      thiscar = Fcar (elt);
      if (XTYPE (thiscar) != Lisp_String)
	continue;
      if (completion_ignore_case)
	thiscar = Fupcase (thiscar);
      tem = Fequal (thiscar, key);
      if (!NILP (tem)) return elt;
      QUIT;
    }
  return Qnil;
}

DEFUN ("minibuffer-complete", Fminibuffer_complete, Sminibuffer_complete, 0, 0, "",
  "Complete the minibuffer contents as far as possible.")
  ()
{
  register int i = do_completion ();
  switch (i)
    {
    case 0:
      return Qnil;

    case 1:
      temp_echo_area_glyphs (" [Sole completion]");
      break;

    case 3:
      temp_echo_area_glyphs (" [Complete, but not unique]");
      break;
    }

  return Qt;
}

DEFUN ("minibuffer-complete-and-exit", Fminibuffer_complete_and_exit,
        Sminibuffer_complete_and_exit, 0, 0, "",
  "Complete the minibuffer contents, and maybe exit.\n\
Exit if the name is valid with no completion needed.\n\
If name was completed to a valid match,\n\
a repetition of this command will exit.")
  ()
{
  register int i;

  /* Allow user to specify null string */
  if (BEGV == ZV)
    goto exit;

  i = do_completion ();
  switch (i)
    {
    case 1:
    case 3:
      goto exit;

    case 4:
      if (!NILP (Vminibuffer_completion_confirm))
	{
	  temp_echo_area_glyphs (" [Confirm]");
	  return Qnil;
	}
      else
	goto exit;

    default:
      return Qnil;
    }
 exit:
  Fthrow (Qexit, Qnil);
  /* NOTREACHED */
}

DEFUN ("minibuffer-complete-word", Fminibuffer_complete_word, Sminibuffer_complete_word,
  0, 0, "",
  "Complete the minibuffer contents at most a single word.\n\
After one word is completed as much as possible, a space or hyphen\n\
is added, provided that matches some possible completion.")
  ()
{
  Lisp_Object completion, tem;
  register int i;
  register unsigned char *completion_string;
  /* We keep calling Fbuffer_string
     rather than arrange for GC to hold onto a pointer to
     one of the strings thus made.  */

  completion = Ftry_completion (Fbuffer_string (),
				Vminibuffer_completion_table,
				Vminibuffer_completion_predicate);
  if (NILP (completion))
    {
      bitch_at_user ();
      temp_echo_area_glyphs (" [No match]");
      return Qnil;
    }
  if (EQ (completion, Qt))
    return Qnil;

#if 0 /* How the below code used to look, for reference */
  tem = Fbuffer_string ();
  b = XSTRING (tem)->data;
  i = ZV - 1 - XSTRING (completion)->size;
  p = XSTRING (completion)->data;
  if (i > 0 ||
      0 <= scmp (b, p, ZV - 1))
    {
      i = 1;
      /* Set buffer to longest match of buffer tail and completion head. */
      while (0 <= scmp (b + i, p, ZV - 1 - i))
	i++;
      del_range (1, i + 1);
      SET_PT (ZV);
    }
#else /* Rewritten code */
  {
    register unsigned char *buffer_string;
    int buffer_length, completion_length;

    tem = Fbuffer_string ();
    buffer_string = XSTRING (tem)->data;
    completion_string = XSTRING (completion)->data;
    buffer_length = XSTRING (tem)->size; /* ie ZV - BEGV */
    completion_length = XSTRING (completion)->size;
    i = buffer_length - completion_length;
    /* Mly: I don't understand what this is supposed to do AT ALL */
    if (i > 0 ||
	0 <= scmp (buffer_string, completion_string, buffer_length))
      {
	/* Set buffer to longest match of buffer tail and completion head. */
	if (i <= 0) i = 1;
	buffer_string += i;
	buffer_length -= i;
	while (0 <= scmp (buffer_string++, completion_string, buffer_length--))
	  i++;
	del_range (1, i + 1);
	SET_PT (ZV);
      }
  }
#endif /* Rewritten code */
  i = ZV - BEGV;

  /* If completion finds next char not unique,
     consider adding a space or a hyphen */
  if (i == XSTRING (completion)->size)
    {
      tem = Ftry_completion (concat2 (Fbuffer_string (), build_string (" ")),
			     Vminibuffer_completion_table,
			     Vminibuffer_completion_predicate);
      if (XTYPE (tem) == Lisp_String)
	completion = tem;
      else
	{
	  tem = Ftry_completion (concat2 (Fbuffer_string (), build_string ("-")),
				 Vminibuffer_completion_table,
				 Vminibuffer_completion_predicate);
	  if (XTYPE (tem) == Lisp_String)
	    completion = tem;
	}
    }      

  /* Now find first word-break in the stuff found by completion.
     i gets index in string of where to stop completing.  */
  completion_string = XSTRING (completion)->data;

  for (; i < XSTRING (completion)->size; i++)
    if (SYNTAX (completion_string[i]) != Sword) break;
  if (i < XSTRING (completion)->size)
    i = i + 1;

  /* If got no characters, print help for user.  */

  if (i == ZV - BEGV)
    {
      if (auto_help)
	Fminibuffer_completion_help ();
      return Qnil;
    }

  /* Otherwise insert in minibuffer the chars we got */

  Ferase_buffer ();
  insert_from_string (completion, 0, i);
  return Qt;
}
\f
DEFUN ("display-completion-list", Fdisplay_completion_list, Sdisplay_completion_list,
       1, 1, 0,
  "Display the list of completions, COMPLETIONS, using `standard-output'.\n\
Each element may be just a symbol or string\n\
or may be a list of two strings to be printed as if concatenated.")
  (completions)
     Lisp_Object completions;
{
  register Lisp_Object tail, elt;
  register int i;
  int column = 0;
  /* No GCPRO needed, since (when it matters) every variable
     points to a non-string that is pointed to by COMPLETIONS.  */
  struct buffer *old = current_buffer;
  if (XTYPE (Vstandard_output) == Lisp_Buffer)
    set_buffer_internal (XBUFFER (Vstandard_output));

  if (NILP (completions))
    write_string ("There are no possible completions of what you have typed.", -1);
  else
    {
      write_string ("Possible completions are:", -1);
      for (tail = completions, i = 0; !NILP (tail); tail = Fcdr (tail), i++)
	{
	  /* this needs fixing for the case of long completions
	     and/or narrow windows */
	  /* Sadly, the window it will appear in is not known
	     until after the text has been made. */
	  if (i & 1)
	    {
	      if (XTYPE (Vstandard_output) == Lisp_Buffer)
		Findent_to (make_number (35), make_number (1));
	      else
		{
		  do
		    {
		      write_string (" ", -1);
		      column++;
		    }
		  while (column < 35);
		}
	    }
	  else
	    {
	      Fterpri (Qnil);
	      column = 0;
	    }
	  elt = Fcar (tail);
	  if (CONSP (elt))
	    {
	      if (XTYPE (Vstandard_output) != Lisp_Buffer)
		{
		  Lisp_Object tem;
		  tem = Flength (Fcar (elt));
		  column += XINT (tem);
		  tem = Flength (Fcar (Fcdr (elt)));
		  column += XINT (tem);
		}
	      Fprinc (Fcar (elt), Qnil);
	      Fprinc (Fcar (Fcdr (elt)), Qnil);
	    }
	  else
	    {
	      if (XTYPE (Vstandard_output) != Lisp_Buffer)
		{
		  Lisp_Object tem;
		  tem = Flength (elt, Qt);
		  column += XINT (tem);
		}
	      Fprinc (elt, Qnil);
	    }
	}
    }

  if (XTYPE (Vstandard_output) == Lisp_Buffer)
    set_buffer_internal (old);
  return Qnil;
}

DEFUN ("minibuffer-completion-help", Fminibuffer_completion_help, Sminibuffer_completion_help,
  0, 0, "",
  "Display a list of possible completions of the current minibuffer contents.")
  ()
{
  Lisp_Object completions;

  message ("Making completion list...");
  completions = Fall_completions (Fbuffer_string (),
				  Vminibuffer_completion_table,
				  Vminibuffer_completion_predicate);
  echo_area_glyphs = 0;

  if (NILP (completions))
    {
      bitch_at_user ();
      temp_echo_area_glyphs (" [No completions]");
    }
  else
    internal_with_output_to_temp_buffer ("*Completions*",
					 Fdisplay_completion_list,
					 Fsort (completions, Qstring_lessp));
  return Qnil;
}
\f
DEFUN ("self-insert-and-exit", Fself_insert_and_exit, Sself_insert_and_exit, 0, 0, "",
  "Terminate minibuffer input.")
  ()
{
  if (XTYPE (last_command_char) == Lisp_Int)
    internal_self_insert (last_command_char, 0);
  else
    bitch_at_user ();

  Fthrow (Qexit, Qnil);
}

DEFUN ("exit-minibuffer", Fexit_minibuffer, Sexit_minibuffer, 0, 0, "",
  "Terminate this minibuffer argument.")
  ()
{
  Fthrow (Qexit, Qnil);
}

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

\f
init_minibuf_once ()
{
  Vminibuffer_list = Qnil;
  staticpro (&Vminibuffer_list);
}

syms_of_minibuf ()
{
  minibuf_level = 0;
  minibuf_prompt = 0;
  minibuf_save_vector_size = 5;
  minibuf_save_vector = (struct minibuf_save_data *) malloc (5 * sizeof (struct minibuf_save_data));

  Qminibuffer_completion_table = intern ("minibuffer-completion-table");
  staticpro (&Qminibuffer_completion_table);

  Qminibuffer_completion_confirm = intern ("minibuffer-completion-confirm");
  staticpro (&Qminibuffer_completion_confirm);

  Qminibuffer_completion_predicate = intern ("minibuffer-completion-predicate");
  staticpro (&Qminibuffer_completion_predicate);

  staticpro (&last_minibuf_string);
  last_minibuf_string = Qnil;

  Quser_variable_p = intern ("user-variable-p");
  staticpro (&Quser_variable_p);



  DEFVAR_BOOL ("completion-auto-help", &auto_help,
    "*Non-nil means automatically provide help for invalid completion input.");
  auto_help = 1;

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

  DEFVAR_BOOL ("enable-recursive-minibuffers", &enable_recursive_minibuffers,
    "*Non-nil means to allow minibuffer commands while in the minibuffer.\n\
More precisely, this variable makes a difference when the minibuffer window\n\
is the selected window.  If you are in some other window, minibuffer commands\n\
are allowed even if a minibuffer is active.");
  enable_recursive_minibuffers = 0;

  DEFVAR_LISP ("minibuffer-completion-table", &Vminibuffer_completion_table,
    "Alist or obarray used for completion in the minibuffer.\n\
This becomes the ALIST argument to `try-completion' and `all-completion'.\n\
\n\
The value may alternatively be a function, which is given three arguments:\n\
  STRING, the current buffer contents;\n\
  PREDICATE, the predicate for filtering possible matches;\n\
  CODE, which says what kind of things to do.\n\
CODE can be nil, t or `lambda'.\n\
nil means to return the best completion of STRING, or nil if there is none.\n\
t means to return a list of all possible completions of STRING.\n\
`lambda' means to return t if STRING is a valid completion as it stands.");
  Vminibuffer_completion_table = Qnil;

  DEFVAR_LISP ("minibuffer-completion-predicate", &Vminibuffer_completion_predicate,
    "Within call to `completing-read', this holds the PREDICATE argument.");
  Vminibuffer_completion_predicate = Qnil;

  DEFVAR_LISP ("minibuffer-completion-confirm", &Vminibuffer_completion_confirm,
    "Non-nil => demand confirmation of completion before exiting minibuffer.");
  Vminibuffer_completion_confirm = Qnil;

  DEFVAR_LISP ("minibuffer-help-form", &Vminibuffer_help_form,
    "Value that `help-form' takes on inside the minibuffer.");
  Vminibuffer_help_form = Qnil;

  defsubr (&Sread_from_minibuffer);
  defsubr (&Seval_minibuffer);
  defsubr (&Sread_minibuffer);
  defsubr (&Sread_string);
  defsubr (&Sread_command);
  defsubr (&Sread_variable);
  defsubr (&Sread_buffer);
  defsubr (&Sread_no_blanks_input);
  defsubr (&Sminibuffer_depth);

  defsubr (&Stry_completion);
  defsubr (&Sall_completions);
  defsubr (&Scompleting_read);
  defsubr (&Sminibuffer_complete);
  defsubr (&Sminibuffer_complete_word);
  defsubr (&Sminibuffer_complete_and_exit);
  defsubr (&Sdisplay_completion_list);
  defsubr (&Sminibuffer_completion_help);

  defsubr (&Sself_insert_and_exit);
  defsubr (&Sexit_minibuffer);

}

keys_of_minibuf ()
{
  initial_define_key (Vminibuffer_local_map, Ctl ('g'),
		      "abort-recursive-edit");
  initial_define_key (Vminibuffer_local_map, Ctl ('m'),
		      "exit-minibuffer");
  initial_define_key (Vminibuffer_local_map, Ctl ('j'),
		      "exit-minibuffer");

  initial_define_key (Vminibuffer_local_ns_map, Ctl ('g'),
		      "abort-recursive-edit");
  initial_define_key (Vminibuffer_local_ns_map, Ctl ('m'),
		      "exit-minibuffer");
  initial_define_key (Vminibuffer_local_ns_map, Ctl ('j'),
		      "exit-minibuffer");

  initial_define_key (Vminibuffer_local_ns_map, ' ',
		      "exit-minibuffer");
  initial_define_key (Vminibuffer_local_ns_map, '\t',
		      "exit-minibuffer");
  initial_define_key (Vminibuffer_local_ns_map, '?',
		      "self-insert-and-exit");

  initial_define_key (Vminibuffer_local_completion_map, Ctl ('g'),
		      "abort-recursive-edit");
  initial_define_key (Vminibuffer_local_completion_map, Ctl ('m'),
		      "exit-minibuffer");
  initial_define_key (Vminibuffer_local_completion_map, Ctl ('j'),
		      "exit-minibuffer");

  initial_define_key (Vminibuffer_local_completion_map, '\t',
		      "minibuffer-complete");
  initial_define_key (Vminibuffer_local_completion_map, ' ',
		      "minibuffer-complete-word");
  initial_define_key (Vminibuffer_local_completion_map, '?',
		      "minibuffer-completion-help");

  initial_define_key (Vminibuffer_local_must_match_map, Ctl ('g'),
		      "abort-recursive-edit");
  initial_define_key (Vminibuffer_local_must_match_map, Ctl ('m'),
		      "minibuffer-complete-and-exit");
  initial_define_key (Vminibuffer_local_must_match_map, Ctl ('j'),
		      "minibuffer-complete-and-exit");
  initial_define_key (Vminibuffer_local_must_match_map, '\t',
		      "minibuffer-complete");
  initial_define_key (Vminibuffer_local_must_match_map, ' ',
		      "minibuffer-complete-word");
  initial_define_key (Vminibuffer_local_must_match_map, '?',
		      "minibuffer-completion-help");
}