@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001, 2002,
-@c 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+@c Copyright (C) 1990-1995, 1998-1999, 2001-2012
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../../info/minibuf
@node Minibuffers, Command Loop, Read and Print, Top
* Intro to Minibuffers:: Basic information about minibuffers.
* Text from Minibuffer:: How to read a straight text string.
* Object from Minibuffer:: How to read a Lisp object or expression.
-* Minibuffer History:: Recording previous minibuffer inputs
- so the user can reuse them.
+* Minibuffer History:: Recording previous minibuffer inputs
+ so the user can reuse them.
* Initial Input:: Specifying initial contents for the minibuffer.
* Completion:: How to invoke and customize completion.
* Yes-or-No Queries:: Asking a question with a simple answer.
-* Multiple Queries:: Asking a series of similar questions.
-* Reading a Password:: Reading a password from the terminal.
+* Multiple Queries:: Asking a series of similar questions.
+* Reading a Password:: Reading a password from the terminal.
* Minibuffer Commands:: Commands used as key bindings in minibuffers.
* Minibuffer Contents:: How such commands access the minibuffer text.
* Minibuffer Windows:: Operating on the special minibuffer windows.
@cindex minibuffer history
@cindex history list
- A @dfn{minibuffer history list} records previous minibuffer inputs so
-the user can reuse them conveniently. A history list is actually a
-symbol, not a list; it is a variable whose value is a list of strings
-(previous inputs), most recent first.
+ A @dfn{minibuffer history list} records previous minibuffer inputs
+so the user can reuse them conveniently. It is a variable whose value
+is a list of strings (previous inputs), most recent first.
- There are many separate history lists, used for different kinds of
-inputs. It's the Lisp programmer's job to specify the right history
-list for each use of the minibuffer.
+ There are many separate minibuffer history lists, used for different
+kinds of inputs. It's the Lisp programmer's job to specify the right
+history list for each use of the minibuffer.
- You specify the history list with the optional @var{hist} argument
-to either @code{read-from-minibuffer} or @code{completing-read}. Here
-are the possible values for it:
+ You specify a minibuffer history list with the optional @var{hist}
+argument to @code{read-from-minibuffer} or @code{completing-read}.
+Here are the possible values for it:
@table @asis
@item @var{variable}
@defopt history-length
The value of this variable specifies the maximum length for all
history lists that don't specify their own maximum lengths. If the
-value is @code{t}, that means there no maximum (don't delete old
+value is @code{t}, that means there is no maximum (don't delete old
elements). The value of @code{history-length} property of the history
list variable's symbol, if set, overrides this variable for that
particular history list.
@menu
* Basic Completion:: Low-level functions for completing strings.
- (These are too low level to use the minibuffer.)
* Minibuffer Completion:: Invoking the minibuffer with completion.
* Completion Commands:: Minibuffer commands that do completion.
* High-Level Completion:: Convenient special cases of completion
- (reading buffer name, file name, etc.)
+ (reading buffer name, file name, etc.).
* Reading File Names:: Using completion to read file names and
shell commands.
* Completion Styles:: Specifying rules for performing completion.
@node Basic Completion
@subsection Basic Completion Functions
- The completion functions @code{try-completion},
-@code{all-completions} and @code{test-completion} have nothing in
-themselves to do with minibuffers. We describe them in this chapter
-so as to keep them near the higher-level completion features that do
-use the minibuffer.
-
- If you store a completion alist in a variable, you should mark the
-variable as ``risky'' with a non-@code{nil}
-@code{risky-local-variable} property.
+ The following completion functions have nothing in themselves to do
+with minibuffers. We describe them here to keep them near the
+higher-level completion features that do use the minibuffer.
@defun try-completion string collection &optional predicate
This function returns the longest common substring of all possible
completions of @var{string} in @var{collection}. The value of
-@var{collection} must be a list of strings or symbols, an alist, an
-obarray, a hash table, or a function that implements a virtual set of
-strings (see below).
+@var{collection} must be a list of strings, an alist whose keys are
+strings or symbols, an obarray, a hash table, or a completion function
+(@pxref{Programmed Completion}).
Completion compares @var{string} against each of the permissible
-completions specified by @var{collection}; if the beginning of the
-permissible completion equals @var{string}, it matches. If no permissible
-completions match, @code{try-completion} returns @code{nil}. If only
-one permissible completion matches, and the match is exact, then
-@code{try-completion} returns @code{t}. Otherwise, the value is the
-longest initial sequence common to all the permissible completions that
-match.
+completions specified by @var{collection}. If no permissible
+completions match, @code{try-completion} returns @code{nil}. If there
+is just one matching completion, and the match is exact, it returns
+@code{t}. Otherwise, it returns the longest initial sequence common
+to all possible matching completions.
If @var{collection} is an alist (@pxref{Association Lists}), the
permissible completions are the elements of the alist that are either
-strings, symbols, or conses whose @sc{car} is a string or symbol.
+strings, or conses whose @sc{car} is a string or symbol.
Symbols are converted to strings using @code{symbol-name}. Other
elements of the alist are ignored. (Remember that in Emacs Lisp, the
elements of alists do not @emph{have} to be conses.) In particular, a
-list of strings or symbols is allowed, even though we usually do not
+list of strings is allowed, even though we usually do not
think of such lists as alists.
@cindex obarray in completion
If @var{collection} is a hash table, then the keys that are strings
are the possible completions. Other keys are ignored.
-You can also use a symbol that is a function as @var{collection}. Then
-the function is solely responsible for performing completion;
+You can also use a function as @var{collection}.
+Then the function is solely responsible for performing completion;
@code{try-completion} returns whatever this function returns. The
function is called with three arguments: @var{string}, @var{predicate}
-and @code{nil}. (The reason for the third argument is so that the same
+and @code{nil} (the reason for the third argument is so that the same
function can be used in @code{all-completions} and do the appropriate
-thing in either case.) @xref{Programmed Completion}.
+thing in either case). @xref{Programmed Completion}.
If the argument @var{predicate} is non-@code{nil}, then it must be a
function of one argument, unless @var{collection} is a hash table, in
@var{string}. The arguments to this function (aside from
@var{nospace}) are the same as those of @code{try-completion}. Also,
this function uses @code{completion-regexp-list} in the same way that
-@code{try-completion} does. The optional argument @var{nospace} only
-matters if @var{string} is the empty string. In that case, if
-@var{nospace} is non-@code{nil}, completions that start with a space
-are ignored.
+@code{try-completion} does.
+
+The optional argument @var{nospace} is obsolete. If it is
+non-@code{nil}, completions that start with a space are ignored unless
+@var{string} starts with a space.
If @var{collection} is a function, it is called with three arguments:
@var{string}, @var{predicate} and @code{t}; then @code{all-completions}
it returns, @code{test-completion} returns in turn.
@end defun
+@defun completion-boundaries string collection predicate suffix
+This function returns the boundaries of the field on which @var{collection}
+will operate, assuming that @var{string} holds the text before point
+and @var{suffix} holds the text after point.
+
+Normally completion operates on the whole string, so for all normal
+collections, this will always return @code{(0 . (length
+@var{suffix}))}. But more complex completion such as completion on
+files is done one field at a time. For example, completion of
+@code{"/usr/sh"} will include @code{"/usr/share/"} but not
+@code{"/usr/share/doc"} even if @code{"/usr/share/doc"} exists.
+Also @code{all-completions} on @code{"/usr/sh"} will not include
+@code{"/usr/share/"} but only @code{"share/"}. So if @var{string} is
+@code{"/usr/sh"} and @var{suffix} is @code{"e/doc"},
+@code{completion-boundaries} will return @code{(5 . 1)} which tells us
+that the @var{collection} will only return completion information that
+pertains to the area after @code{"/usr/"} and before @code{"/doc"}.
+@end defun
+
+If you store a completion alist in a variable, you should mark the
+variable as ``risky'' with a non-@code{nil}
+@code{risky-local-variable} property. @xref{File Local Variables}.
+
@defvar completion-ignore-case
-If the value of this variable is non-@code{nil}, Emacs does not
-consider case significant in completion. Note, however, that this
-variable is overridden by @code{read-file-name-completion-ignore-case}
-within @code{read-file-name} (@pxref{Reading File Names}), and by
-@code{read-buffer-completion-ignore-case} within @code{read-buffer}
-(@pxref{High-Level Completion}).
+If the value of this variable is non-@code{nil}, case is not
+considered significant in completion. Within @code{read-file-name},
+this variable is overridden by
+@code{read-file-name-completion-ignore-case} (@pxref{Reading File
+Names}); within @code{read-buffer}, it is overridden by
+@code{read-buffer-completion-ignore-case} (@pxref{High-Level
+Completion}).
@end defvar
@defvar completion-regexp-list
@end smallexample
@end defmac
+The function @code{completion-in-region} provides a convenient way to
+perform completion on an arbitrary stretch of text in an Emacs buffer:
+
+@defun completion-in-region start end collection &optional predicate
+This function completes the text in the current buffer between the
+positions @var{start} and @var{end}, using @var{collection}. The
+argument @var{collection} has the same meaning as in
+@code{try-completion} (@pxref{Basic Completion}).
+
+This function inserts the completion text directly into the current
+buffer. Unlike @code{completing-read} (@pxref{Minibuffer
+Completion}), it does not activate the minibuffer.
+
+For this function to work, point must be somewhere between @var{start}
+and @var{end}.
+@end defun
+
@node Minibuffer Completion
@subsection Completion and the Minibuffer
@cindex minibuffer completion
@var{prompt}, which must be a string.
The actual completion is done by passing @var{collection} and
-@var{predicate} to the function @code{try-completion}. This happens
-in certain commands bound in the local keymaps used for completion.
-Some of these commands also call @code{test-completion}. Thus, if
-@var{predicate} is non-@code{nil}, it should be compatible with
-@var{collection} and @code{completion-ignore-case}. @xref{Definition
-of test-completion}.
+@var{predicate} to the function @code{try-completion} (@pxref{Basic
+Completion}). This happens in certain commands bound in the local
+keymaps used for completion. Some of these commands also call
+@code{test-completion}. Thus, if @var{predicate} is non-@code{nil},
+it should be compatible with @var{collection} and
+@code{completion-ignore-case}. @xref{Definition of test-completion}.
The value of the optional argument @var{require-match} determines how
the user may exit the minibuffer:
@end defun
@defopt read-buffer-function
-This variable specifies how to read buffer names. For example, if you
-set this variable to @code{iswitchb-read-buffer}, all Emacs commands
-that call @code{read-buffer} to read a buffer name will actually use the
-@code{iswitchb} package to read it.
+This variable specifies how to read buffer names. The function is
+called with the arguments passed to @code{read-buffer}. For example,
+if you set this variable to @code{iswitchb-read-buffer}, all Emacs
+commands that call @code{read-buffer} to read a buffer name will
+actually use the @code{iswitchb} package to read it.
@end defopt
@defopt read-buffer-completion-ignore-case
@deffn Command read-color &optional prompt convert allow-empty display
This function reads a string that is a color specification, either the
color's name or an RGB hex value such as @code{#RRRGGGBBB}. It
-prompts with @var{prompt} (default: @code{"Color (name or #R+G+B+):"})
+prompts with @var{prompt} (default: @code{"Color (name or #RGB triplet):"})
and provides completion for color names, but not for hex RGB values.
In addition to names of standard colors, completion candidates include
the foreground and background colors at point.
Valid RGB values are described in @ref{Color Names}.
-The function's return value is the color name typed by the user in the
+The function's return value is the string typed by the user in the
minibuffer. However, when called interactively or if the optional
-argument @var{convert} is non-@code{nil}, it converts the name into
-the color's RGB value and returns that value as a string. If an
-invalid color name was specified, this function signals an error,
-except that empty color names are allowed when @code{allow-empty} is
+argument @var{convert} is non-@code{nil}, it converts any input color
+name into the corresponding RGB value string and instead returns that.
+This function requires a valid color specification to be input.
+Empty color names are allowed when @code{allow-empty} is
non-@code{nil} and the user enters null input.
Interactively, or when @var{display} is non-@code{nil}, the return
default directory.
@defun read-file-name prompt &optional directory default require-match initial predicate
-This function reads a file name in the minibuffer, prompting with
-@var{prompt} and providing completion.
+This function reads a file name, prompting with @var{prompt} and
+providing completion.
+
+As an exception, this function reads a file name using a graphical
+file dialog instead of the minibuffer, if (i) it is invoked via a
+mouse command, and (ii) the selected frame is on a graphical display
+supporting such dialogs, and (iii) the variable @code{use-dialog-box}
+is non-@code{nil} (@pxref{Dialog Boxes,, Dialog Boxes, emacs, The GNU
+Emacs Manual}), and (iv) the @var{directory} argument, described
+below, does not specify a remote file (@pxref{Remote Files,, Remote
+Files, emacs, The GNU Emacs Manual}). The exact behavior when using a
+graphical file dialog is platform-dependent. Here, we simply document
+the behavior when using the minibuffer.
+
+@code{read-file-name} does not automatically expand the returned file
+name. You must call @code{expand-file-name} yourself if an absolute
+file name is required.
The optional argument @var{require-match} has the same meaning as in
-@code{completing-read}. @xref{Minibuffer Completion}.
-
-@code{read-file-name} uses
-@code{minibuffer-local-filename-completion-map} as the keymap if
-@var{require-match} is @code{nil}, and uses
-@code{minibuffer-local-filename-must-match-map} if @var{require-match}
-is non-@code{nil}. @xref{Completion Commands}.
+@code{completing-read}. @xref{Minibuffer Completion}. If
+@var{require-match} is @code{nil}, the local keymap in the minibuffer
+is @code{minibuffer-local-filename-completion-map}; otherwise, it is
+@code{minibuffer-local-filename-must-match-map}. @xref{Completion
+Commands}.
The argument @var{directory} specifies the directory to use for
-completion of relative file names. It should be an absolute directory
+completing relative file names. It should be an absolute directory
name. If @code{insert-default-directory} is non-@code{nil},
@var{directory} is also inserted in the minibuffer as initial input.
It defaults to the current buffer's value of @code{default-directory}.
-@c Emacs 19 feature
If you specify @var{initial}, that is an initial file name to insert
in the buffer (after @var{directory}, if that is inserted). In this
case, point goes at the beginning of @var{initial}. The default for
possibilities. A file name is an acceptable value if @var{predicate}
returns non-@code{nil} for it.
-@code{read-file-name} does not automatically expand file names. You
-must call @code{expand-file-name} yourself if an absolute file name is
-required.
-
-Here is an example:
+Here is an example of using @code{read-file-name}:
@example
@group
@var{all-completions} functions.
@end defvar
- By default, @code{completion-styles-alist} contains four pre-defined
+ By default, @code{completion-styles-alist} contains five pre-defined
completion styles: @code{basic}, a basic completion style;
@code{partial-completion}, which does partial completion (completing
each word in the input separately); @code{emacs22}, which performs
-completion according to the rules used in Emacs 22; and
-@code{emacs21}, which performs completion according to the rules used
-in Emacs 21.
+completion according to the rules used in Emacs 22; @code{emacs21},
+which performs completion according to the rules used in Emacs 21; and
+@code{initials}, which completes acronyms and initialisms.
@node Programmed Completion
@subsection Programmed Completion
@cindex programmed completion
- Sometimes it is not possible to create an alist or an obarray
-containing all the intended possible completions. In such a case, you
-can supply your own function to compute the completion of a given string.
-This is called @dfn{programmed completion}.
+ Sometimes it is not possible or convenient to create an alist or
+an obarray containing all the intended possible completions ahead
+of time. In such a case, you can supply your own function to compute
+the completion of a given string. This is called @dfn{programmed
+completion}. Emacs uses programmed completion when completing file
+names (@pxref{File Name Completion}), among many other cases.
- To use this feature, pass a symbol with a function definition as the
-@var{collection} argument to @code{completing-read}. The function
+ To use this feature, pass a function as the @var{collection}
+argument to @code{completing-read}. The function
@code{completing-read} arranges to pass your completion function along
-to @code{try-completion} and @code{all-completions}, which will then let
-your function do all the work.
+to @code{try-completion}, @code{all-completions}, and other basic
+completion functions, which will then let your function do all
+the work.
The completion function should accept three arguments:
and ignore the possible match if the predicate returns @code{nil}.
@item
-A flag specifying the type of operation.
+A flag specifying the type of operation. The best way to think about
+it is that the function stands for an object (in the
+``object-oriented'' sense of the word), and this third argument
+specifies which method to run.
@end itemize
- There are three flag values for three operations:
+ There are currently four methods, i.e. four flag values, one for
+each of the four different basic operations:
@itemize @bullet
@item
@code{lambda} specifies @code{test-completion}. The completion
function should return @code{t} if the specified string is an exact
match for some possibility; @code{nil} otherwise.
-@end itemize
- It would be consistent and clean for completion functions to allow
-lambda expressions (lists that are functions) as well as function
-symbols as @var{collection}, but this is impossible. Lists as
-completion tables already have other meanings, and it would be
-unreliable to treat one differently just because it is also a possible
-function. So you must arrange for any function you wish to use for
-completion to be encapsulated in a symbol.
-
- Emacs uses programmed completion when completing file names.
-@xref{File Name Completion}.
+@item
+@code{(boundaries . SUFFIX)} specifies @code{completion-boundaries}.
+The function should return a value of the form @code{(boundaries
+START . END)} where START is the position of the beginning boundary
+in the string to complete, and END is the position of the end boundary
+in SUFFIX.
+@end itemize
@defun completion-table-dynamic function
This function is a convenient way to write a function that can act as
and the interface for programmed completion functions.
@end defun
+@defvar completion-annotate-function
+The value of this variable, if non-@code{nil}, should be a function
+for ``annotating'' the entries in the @samp{*Completions*} buffer.
+The function should accept a single argument, the completion string
+for an entry. It should return an additional string to display next
+to that entry in the @samp{*Completions*} buffer, or @code{nil} if no
+additional string is to be displayed.
+
+The function can determine the collection used for the current
+completion via the variable @code{minibuffer-completion-table}
+(@pxref{Completion Commands}).
+@end defvar
+
@node Yes-or-No Queries
@section Yes-or-No Queries
@cindex asking the user questions
actual message is obtained by passing @var{string} and @var{args}
through @code{format}. @xref{Formatting Strings}.
@end defun
-
-@ignore
- arch-tag: bba7f945-9078-477f-a2ce-18818a6e1218
-@end ignore