2952 lines
130 KiB
Plaintext
2952 lines
130 KiB
Plaintext
This is doc0jZUSv.info, produced by makeinfo version 6.7 from
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compat.texi.
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Copyright © 2022-2023 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this
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document under the terms of the GNU Free Documentation License,
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Version 1.3 or any later version published by the Free Software
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Foundation; with no Invariant Sections, with the Front-Cover Texts
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being “A GNU Manual,” and with the Back-Cover Texts as in (a)
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||
below. A copy of the license is included in the section entitled
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||
“GNU Free Documentation License.”
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(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
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modify this GNU manual.”
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INFO-DIR-SECTION Emacs
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START-INFO-DIR-ENTRY
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* Compat: (compat). Compatibility Library for Emacs Lisp.
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END-INFO-DIR-ENTRY
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File: doc0jZUSv.info, Node: Top, Next: Introduction, Up: (dir)
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"Compat" Manual
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***************
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This manual documents the usage of the "Compat" Emacs lisp library, the
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forward-compatibility library for Emacs Lisp, corresponding to version
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29.1.4.1.
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Copyright © 2022-2023 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this
|
||
document under the terms of the GNU Free Documentation License,
|
||
Version 1.3 or any later version published by the Free Software
|
||
Foundation; with no Invariant Sections, with the Front-Cover Texts
|
||
being “A GNU Manual,” and with the Back-Cover Texts as in (a)
|
||
below. A copy of the license is included in the section entitled
|
||
“GNU Free Documentation License.”
|
||
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||
(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
|
||
modify this GNU manual.”
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* Menu:
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* Introduction::
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* Support::
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* Development::
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* Function Index::
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* Variable Index::
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— The Detailed Node Listing —
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Introduction
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* Overview::
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* Usage::
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* Limitations::
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Support
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* Emacs 25.1:: Compatibility support for Emacs 25.1
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* Emacs 26.1:: Compatibility support for Emacs 26.1
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* Emacs 27.1:: Compatibility support for Emacs 27.1
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* Emacs 28.1:: Compatibility support for Emacs 28.1
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* Emacs 29.1:: Compatibility support for Emacs 29.1
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File: doc0jZUSv.info, Node: Introduction, Next: Support, Prev: Top, Up: Top
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1 Introduction
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**************
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* Menu:
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* Overview::
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* Usage::
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* Limitations::
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File: doc0jZUSv.info, Node: Overview, Next: Usage, Up: Introduction
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1.1 Overview
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============
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The objective of Compat is to provide "forwards compatibility" library
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for Emacs Lisp. By using Compat, an Elisp package does not have to make
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the decision to either use new and useful functionality or support old
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versions of Emacs.
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The library provides support back until Emacs 24.4. The intended
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audience are package developers that are interested in using newer
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developments, without having to break compatibility.
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File: doc0jZUSv.info, Node: Usage, Next: Limitations, Prev: Overview, Up: Introduction
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1.2 Usage
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=========
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The intended use-case for this library is for package developers to add
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as a dependency in the header:
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;; Package-Requires: ((emacs "24.4") (compat "29.1.4.1"))
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There is no need to depend on ‘emacs’ 24.4 specifically. One can
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choose to any newer version, if features not provided by Compat
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necessitate it, for example bug fixes or UI improvements.
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In any file where compatibility forms are used, a
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(require 'compat)
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should be added early on. In packages which are part of Emacs itself
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and which want to take advantage of Compat, the ‘noerror’ flag should be
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specified: ‘(require 'compat nil 'noerror)’. In the future a minimal
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version of Compat may be added to the Emacs core, such that the
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‘noerror’ flag will not be necessary anymore.
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This will load all necessary Compat definitions. Compat also loads
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the ‘seq’ library which is preloaded by default on Emacs 29. Note that
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if Compat is installed on a recent version of Emacs, all of the
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definitions are disabled at compile time, such that no negative
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performance impact is incurred.
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Note that Compat provides replacement functions with extended
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functionality for functions that are already defined (‘sort’, ‘assoc’,
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...). These functions may have changed their calling convention
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(additional optional arguments) or may have changed their behavior.
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These functions must be looked up explicitly with ‘compat-function’ or
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called explicitly with ‘compat-call’. We call them “Extended
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Definitions”. In contrast, newly “Added Definitions” can be called as
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usual.
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(compat-call assoc key alist testfn) ;; Call extended `assoc'
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(mapcan fun seq) ;; Call newly added `mapcan'
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-- Macro: compat-call fun &rest args
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This macro calls the compatibility function FUN with ARGS. Many
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functions provided by Compat can be called directly without this
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macro. However in the case where Compat provides an alternative
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version of an existing function, the function call has to go
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through ‘compat-call’. This happens for example when the calling
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convention of a function has changed.
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-- Macro: compat-function fun
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This macro returns the compatibility function symbol for FUN. See
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‘compat-call’ for a more convenient macro to directly call
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compatibility functions.
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If Compat is used in core packages, where Compat must be required
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currently with the ‘noerror’ flag, the macros ‘compat-call’ and
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‘compat-function’ ar not available. In the future the macros could be
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added to subr. Alternatively a minimal version of compat.el could be
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added to the core. For now it is necessary to replicate the definition
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of the macros within core packages. For example the package ERC defines
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its own macro ‘erc-compat-call’, which replicates the Compat definition
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precisely.
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This design has been chosen since Compat does not advise or override
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existing functions. Generally Compat is written in defensive style
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which is supposed to reduce potential breakage, and to increase the
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chances of staying binary compatible across releases. The extensive
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test coverage ensures that we can maintain high quality, which is
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crucial for Compat which is not restricted to a namespace like usual
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libraries.
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If you intend to use a compatibility function in your code it is
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recommended that you take a look at the test suite ‘compat-tests.el’.
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There you can see the supported calling conventions, which are
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guaranteed to work on the supported Emacs versions. We ensure this
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using continuous integration. All functions provided by Compat are
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covered by the test suite. There is a link to the corresponding test on
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the first line of each definition.
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You may want to subscribe to the compat-announce
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(https://lists.sr.ht/~pkal/compat-announce) mailing list to be notified
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when new versions are released or relevant changes are made. We also
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provide a development mailing list
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(https://lists.sr.ht/~pkal/compat-devel) (~pkal/compat-devel@lists.sr.ht
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<~pkal/compat-devel@lists.sr.ht>).
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File: doc0jZUSv.info, Node: Limitations, Prev: Usage, Up: Introduction
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1.3 Limitations
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===============
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The Compat library has a number of limitations. Complete backwards
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compatibility cannot be provided due to the scope of Compat and for
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technical reasons. The scope is intentionally restricted in order to
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limit the size of Compat and to ensure that the library stays
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maintainable.
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Emacs version 24.4 is chosen as the oldest version supported by
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Compat, since Elisp has seen significant changes at that version. On
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the library level, subr-x was introduced in 24.4. Most popular Emacs
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packages already require 24.4 or even newer versions of Emacs.
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Supporting for more historical Emacs versions would complicate
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maintainance significantly while only few packages and users would
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benefit.
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Below we list a number of reasons why certain functionality cannot be
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provided. Note that in some special cases exceptions can be made and
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functions can still be added to Compat even if they satisfy the criteria
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from the list. In case you miss functionality which you think should
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belong here, a *note report: Development. would be much appreciated.
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• The additional functionality is a command or a user-facing minor or
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major mode. Compat is limited to functionality on the “library
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level”. Generally functions provided by Compat are
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non-interactive, such that the user interface (M-x) is unaffected
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by the presence of Compat.
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• The function is not useful for package authors or not intended to
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be used by packages, but is only useful on the configuration level.
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The macro ‘setopt’ is such an example.
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• Private (double dashed) functions are not ported back. If Compat
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includes some private functions, they are meant purely for internal
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||
usage.
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• The added or extended function belongs to the “application level”
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and not the “library level”. Features which are not preloaded
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often belong to the “application level”. Application examples are
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programming modes or modes like Dired, IRC and Gnus. If these
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modes are extended with new functions, these are not ported back.
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||
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||
• An existing function or macro was extended by some new
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functionality. To support these cases, the function or macro would
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have to be advised. Since this is invasive and adds significant
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overhead, even when the new feature is not used, Compat does not
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use advices. As a compromise, compatibility functions and macros
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with a changed calling convention or behavior can be accessed via
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the ‘compat-function’ and ‘compat-call’ macros. In this manual we
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call such definitions “Extended Definitions”. An example is the
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function ‘plist-get’. Note that extended functions are subject to
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closer scrutiny, since their usage via ‘compat-call’ is not
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completely painless. If a particular extended function does not
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see much usage or the extension yields only marginal benefits, we
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may not provide it as part of Compat.
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• Bug fixes are usually not ported back as part of Compat. Sometimes
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library functions show wrong behavior for edge cases. In those
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cases Compat could in principle provide a compatibility function
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which is invoked via ‘compat-call’. Such extended definitions
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||
would increase the maintainance burden of Compat. At the same time
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the benefits would be small given that Compat does not override
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existing definitions.
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• The definition belongs to an Emacs core package, which is also
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distributed via ELPA. Compat does not have to provide backward
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compatibility for core packages since the updated package can be
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installed directly from ELPA. Examples include the libraries xref,
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project, seq, map and transient.
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• New functionality depends on an entire new, non-trivial core
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library, which is infeasible to duplicate within Compat. If a
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backport of such a library is required, the preferred approach is
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||
to either release the library separately on GNU ELPA as a core
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package or as a separately maintained GNU ELPA package. An example
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||
is the iso8601 library.
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||
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||
• New functionality was implemented in the C core, or depends on
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external libraries that cannot be reasonably duplicated in the
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scope of a compatibility library. Sometimes new functions on the C
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||
level rely on internal data structures, which we cannot access,
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||
rendering a backport impossible. For example a missing libxml
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cannot be emulated.
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||
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• The semantics of Elisp changed on a deep level. For example the
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||
addition of Bigint support in Emacs 27.1 cannot be replicated on
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the level of Compat.
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||
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||
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File: doc0jZUSv.info, Node: Support, Next: Development, Prev: Introduction, Up: Top
|
||
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||
2 Support
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||
*********
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||
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||
This section goes into the features that Compat manages and doesn’t
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manage to provide for each Emacs version.
|
||
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||
* Menu:
|
||
|
||
* Emacs 25.1:: Compatibility support for Emacs 25.1
|
||
* Emacs 26.1:: Compatibility support for Emacs 26.1
|
||
* Emacs 27.1:: Compatibility support for Emacs 27.1
|
||
* Emacs 28.1:: Compatibility support for Emacs 28.1
|
||
* Emacs 29.1:: Compatibility support for Emacs 29.1
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Emacs 25.1, Next: Emacs 26.1, Up: Support
|
||
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2.1 Emacs 25.1
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||
==============
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2.1.1 Added Definitions
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-----------------------
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The following functions and macros are implemented in Emacs 25.1. These
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functions are made available by Compat on Emacs versions older than
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25.1.
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-- User Option: text-quoting-style
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The value of this user option is a symbol that specifies the style
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Emacs should use for single quotes in the wording of help and
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messages. If the option’s value is ‘curve’, the style is ‘like
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this’ with curved single quotes. If the value is ‘straight’, the
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style is 'like this' with straight apostrophes. If the value is
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‘grave’, quotes are not translated and the style is `like this'
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with grave accent and apostrophe, the standard style before Emacs
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version 25. The default value ‘nil’ acts like ‘curve’ if curved
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single quotes seem to be displayable, and like ‘grave’ otherwise.
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This option is useful on platforms that have problems with curved
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quotes. You can customize it freely according to your personal
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preference.
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-- Function: region-bounds
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Return the boundaries of the region. Value is a list of one or
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more cons cells of the form ‘(start . end)’. It will have more
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than one cons cell when the region is non-contiguous, see
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‘region-noncontiguous-p’ and ‘extract-rectangle-bounds’.
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-- Function: region-noncontiguous-p
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Return non-nil if the region contains several pieces. An example
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is a rectangular region handled as a list of separate contiguous
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regions for each line.
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-- Macro: save-mark-and-excursion body...
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This macro is like ‘save-excursion’, but also saves and restores
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the mark location and ‘mark-active’. This macro does what
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‘save-excursion’ did before Emacs 25.1.
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-- Function: format-message string &rest objects
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This function acts like ‘format’, except it also converts any grave
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accents (`) and apostrophes (') in STRING as per the value of
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‘text-quoting-style’.
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Typically grave accent and apostrophe in the format translate to
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matching curved quotes, e.g., "Missing `%s'" might result in
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"Missing ‘foo’". *Note (elisp)Text Quoting Style::, for how to
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influence or inhibit this translation.
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*note (elisp)Formatting Strings::.
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-- Function: directory-name-p filename
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This function returns non-‘nil’ if FILENAME ends with a directory
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separator character. This is the forward slash ‘/’ on GNU and
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other POSIX-like systems; MS-Windows and MS-DOS recognize both the
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forward slash and the backslash ‘\’ as directory separators.
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*Note (elisp)Directory Names::.
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-- Function: string-greaterp string1 string2
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This function returns the result of comparing STRING1 and STRING2
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in the opposite order, i.e., it is equivalent to calling
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‘(string-lessp STRING2 STRING1)’.
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*Note (elisp)Text Comparison::.
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-- Macro: with-file-modes mode body...
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This macro evaluates the BODY forms with the default permissions
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for new files temporarily set to MODES (whose value is as for
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‘set-file-modes’ above). When finished, it restores the original
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default file permissions, and returns the value of the last form in
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BODY.
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This is useful for creating private files, for example.
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*Note (elisp)Changing Files::.
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-- Function: alist-get key alist &optional default remove
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This function is similar to ‘assq’. It finds the first association
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‘(KEY . VALUE)’ by comparing KEY with ALIST elements, and, if
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found, returns the VALUE of that association. If no association is
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found, the function returns DEFAULT.
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||
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||
This is a generalized variable (*note (elisp)Generalized
|
||
Variables::) that can be used to change a value with ‘setf’. When
|
||
using it to set a value, optional argument REMOVE non-‘nil’ means
|
||
to remove KEY’s association from ALIST if the new value is ‘eql’ to
|
||
DEFAULT.
|
||
|
||
*note (elisp)Association Lists::.
|
||
|
||
-- Macro: if-let (bindings...) then &rest else...
|
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As with ‘let*’, BINDINGS will consist of ‘(SYMBOL VALUE-FORM)’
|
||
entries that are evaluated and bound sequentially. If all
|
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VALUE-FORM evaluate to non-‘nil’ values, then THEN is evaluated as
|
||
were the case with a regular ‘let*’ expression, with all the
|
||
variables bound. If any VALUE-FORM evaluates to ‘nil’, ELSE is
|
||
evaluated, without any bound variables.
|
||
|
||
A binding may also optionally drop the SYMBOL, and simplify to
|
||
‘(VALUE-FORM)’ if only the test is of interest.
|
||
|
||
For the sake of backwards compatibility, it is possible to write a
|
||
single binding without a binding list:
|
||
|
||
(if-let* (SYMBOL (test)) foo bar)
|
||
≡
|
||
(if-let* ((SYMBOL (test))) foo bar)
|
||
|
||
-- Macro: when-let (bindings...) &rest body
|
||
As with ‘when’, if one is only interested in the case where all
|
||
BINDINGS are non-nil. Otherwise BINDINGS are interpreted just as
|
||
they are by ‘if-let*’.
|
||
|
||
-- Function: hash-table-empty hash-table
|
||
Check whether HASH-TABLE is empty (has 0 elements).
|
||
|
||
-- Macro: thread-first &rest forms
|
||
Combine FORMS into a single expression by “threading” each element
|
||
as the _first_ argument of their successor. Elements of FORMS can
|
||
either be an list of an atom.
|
||
|
||
For example, consider the threading expression and it’s equivalent
|
||
macro expansion:
|
||
|
||
(thread-first
|
||
5
|
||
(+ 20)
|
||
(/ 25)
|
||
-
|
||
(+ 40))
|
||
≡
|
||
(+ (- (/ (+ 5 20) 25)) 40)
|
||
|
||
Note how the single ‘-’ got converted into a list before threading.
|
||
This example uses arithmetic functions, but ‘thread-first’ is not
|
||
restricted to arithmetic or side-effect free code.
|
||
|
||
-- Macro: thread-last &rest forms
|
||
Combine FORMS into a single expression by “threading” each element
|
||
as the _last_ argument of their successor. Elements of FORMS can
|
||
either be an list of an atom.
|
||
|
||
For example, consider the threading expression and it’s equivalent
|
||
macro expansion:
|
||
|
||
(thread-first
|
||
5
|
||
(+ 20)
|
||
(/ 25)
|
||
-
|
||
(+ 40))
|
||
≡
|
||
(+ 40 (- (/ 25 (+ 20 5))))
|
||
|
||
Note how the single ‘-’ got converted into a list before threading.
|
||
This example uses arithmetic functions, but ‘thread-last’ is not
|
||
restricted to arithmetic or side-effect free code.
|
||
|
||
-- Function: macroexpand-1 form &optional environment
|
||
This function expands macros like ‘macroexpand’, but it only
|
||
performs one step of the expansion: if the result is another macro
|
||
call, ‘macroexpand-1’ will not expand it.
|
||
|
||
*Note Expansion: (elisp)Expansion.
|
||
|
||
-- Function: macroexp-quote e
|
||
Return an expression E such that ‘(eval e)’ is V.
|
||
|
||
-- Function: macroexp-parse body
|
||
Parse a function BODY into ‘(declarations . exps)’.
|
||
|
||
-- Function: bool-vector &rest objects
|
||
This function creates and returns a bool-vector whose elements are
|
||
the arguments, OBJECTS.
|
||
|
||
*Note (elisp)Bool-Vectors::.
|
||
|
||
2.1.2 Extended Definitions
|
||
--------------------------
|
||
|
||
These functions must be called explicitly via ‘compat-call’, since their
|
||
calling convention or behavior was extended in Emacs 25.1:
|
||
|
||
-- Function: compat-call sort sequence predicate
|
||
This function sorts SEQUENCE stably. Note that this function
|
||
doesn’t work for all sequences; it may be used only for lists and
|
||
vectors. If SEQUENCE is a list, it is modified destructively.
|
||
This functions returns the sorted SEQUENCE and compares elements
|
||
using PREDICATE. A stable sort is one in which elements with equal
|
||
sort keys maintain their relative order before and after the sort.
|
||
Stability is important when successive sorts are used to order
|
||
elements according to different criteria.
|
||
|
||
*Note (elisp)Sequence Functions::.
|
||
|
||
The compatibility version adds support for vectors to be sorted,
|
||
not just lists.
|
||
|
||
2.1.3 Missing Definitions
|
||
-------------------------
|
||
|
||
Compat does not provide support for the following Lisp features
|
||
implemented in 25.1:
|
||
|
||
• The function ‘macroexp-macroexpand’.
|
||
• The macro ‘macroexp-let2*’.
|
||
• The function ‘directory-files-recursively’.
|
||
• New ‘pcase’ patterns.
|
||
• The hook ‘prefix-command-echo-keystrokes-functions’ and
|
||
‘prefix-command-preserve-state-hook’.
|
||
• The hook ‘pre-redisplay-functions’.
|
||
• The function ‘make-process’.
|
||
• Support for the variable ‘inhibit-message’.
|
||
• The ‘define-inline’ functionality.
|
||
• The functions ‘string-collate-lessp’ and ‘string-collate-equalp’.
|
||
• The function ‘funcall-interactively’.
|
||
• The function ‘buffer-substring-with-bidi-context’.
|
||
• The function ‘font-info’.
|
||
• The function ‘default-font-width’.
|
||
• The function ‘window-font-height’ and ‘window-font-width’.
|
||
• The function ‘window-max-chars-per-line’.
|
||
• The function ‘set-binary-mode’.
|
||
• The functions ‘bufferpos-to-filepos’ and ‘filepos-to-bufferpos’.
|
||
• The ‘thunk’ library.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Emacs 26.1, Next: Emacs 27.1, Prev: Emacs 25.1, Up: Support
|
||
|
||
2.2 Emacs 26.1
|
||
==============
|
||
|
||
2.2.1 Added Definitions
|
||
-----------------------
|
||
|
||
The following functions and macros are implemented in Emacs 26.1. These
|
||
functions are made available by Compat on Emacs versions older than
|
||
26.1.
|
||
|
||
-- Function: assoc-delete-all key alist
|
||
This function is like ‘assq-delete-all’ except that it uses ‘equal’
|
||
to compare elements.
|
||
|
||
-- Function: read-answer question answers
|
||
This function prompts the user with text in QUESTION, which should
|
||
end in the ‘SPC’ character. The function includes in the prompt
|
||
the possible responses in ANSWERS by appending them to the end of
|
||
QUESTION. The possible responses are provided in ANSWERS as an
|
||
alist whose elements are of the following form:
|
||
|
||
(LONG-ANSWER SHORT-ANSWER HELP-MESSAGE)
|
||
|
||
where LONG-ANSWER is the complete text of the user response, a
|
||
string; SHORT-ANSWER is a short form of the same response, a single
|
||
character or a function key; and HELP-MESSAGE is the text that
|
||
describes the meaning of the answer. If the variable
|
||
‘read-answer-short’ is non-‘nil’, the prompt will show the short
|
||
variants of the possible answers and the user is expected to type
|
||
the single characters/keys shown in the prompt; otherwise the
|
||
prompt will show the long variants of the answers, and the user is
|
||
expected to type the full text of one of the answers and end by
|
||
pressing <RET>. If ‘use-dialog-box’ is non-‘nil’, and this
|
||
function was invoked by mouse events, the question and the answers
|
||
will be displayed in a GUI dialog box.
|
||
|
||
The function returns the text of the LONG-ANSWER selected by the
|
||
user, regardless of whether long or short answers were shown in the
|
||
prompt and typed by the user.
|
||
|
||
Here is an example of using this function:
|
||
|
||
(let ((read-answer-short t))
|
||
(read-answer "Foo "
|
||
'(("yes" ?y "perform the action")
|
||
("no" ?n "skip to the next")
|
||
("all" ?! "perform for the rest without more questions")
|
||
("help" ?h "show help")
|
||
("quit" ?q "exit"))))
|
||
|
||
-- Function: mapcan function sequence
|
||
This function applies FUNCTION to each element of SEQUENCE, like
|
||
‘mapcar’, but instead of collecting the results into a list, it
|
||
returns a single list with all the elements of the results (which
|
||
must be lists), by altering the results (using ‘nconc’; *note
|
||
(elisp)Rearrangement::). Like with ‘mapcar’, SEQUENCE can be of
|
||
any type except a char-table.
|
||
|
||
;; Contrast this: (mapcar #'list '(a b c d)) ⇒ ((a) (b) (c)
|
||
(d)) ;; with this: (mapcan #'list '(a b c d)) ⇒ (a b c d)
|
||
|
||
*Note (elisp)Mapping Functions::.
|
||
|
||
-- Function: cXXXr
|
||
-- Function: cXXXXr
|
||
*Note (elisp)List Elements::.
|
||
|
||
-- Function: gensym &optional prefix
|
||
This function returns a symbol using ‘make-symbol’, whose name is
|
||
made by appending ‘gensym-counter’ to PREFIX and incrementing that
|
||
counter, guaranteeing that no two calls to this function will
|
||
generate a symbol with the same name. The prefix defaults to
|
||
‘"g"’.
|
||
|
||
-- Variable: gensym-counter
|
||
See ‘gensym’.
|
||
|
||
-- Function: buffer-hash &optional buffer-or-name
|
||
Return a hash of BUFFER-OR-NAME. If ‘nil’, this defaults to the
|
||
current buffer. As opposed to ‘secure-hash’, this function
|
||
computes the hash based on the internal representation of the
|
||
buffer, disregarding any coding systems. It’s therefore only
|
||
useful when comparing two buffers running in the same Emacs, and is
|
||
not guaranteed to return the same hash between different Emacs
|
||
versions. It should be somewhat more efficient on larger buffers
|
||
than ‘secure-hash’ is, and should not allocate more memory.
|
||
|
||
-- Macro: file-name-unquote name
|
||
This macro removes the quotation prefix ‘/:’ from the file NAME, if
|
||
any. If NAME is a remote file name, the local part of NAME is
|
||
unquoted.
|
||
|
||
-- Function: file-name-quoted-p name
|
||
This macro returns non-‘nil’, when NAME is quoted with the prefix
|
||
‘/:’. If NAME is a remote file name, the local part of NAME is
|
||
checked.
|
||
|
||
*Note (elisp)File Name Expansion::.
|
||
|
||
-- Function: file-name-quote name
|
||
This macro adds the quotation prefix ‘/:’ to the file NAME. For a
|
||
local file NAME, it prefixes NAME with ‘/:’. If NAME is a remote
|
||
file name, the local part of NAME (*note (elisp)Magic File Names::)
|
||
is quoted. If NAME is already a quoted file name, NAME is returned
|
||
unchanged.
|
||
|
||
(substitute-in-file-name (compat-call file-name-quote "bar/~/foo")) ⇒
|
||
"/:bar/~/foo"
|
||
|
||
(substitute-in-file-name (compat-call file-name-quote "/ssh:host:bar/~/foo"))
|
||
⇒ "/ssh:host:/:bar/~/foo"
|
||
|
||
The macro cannot be used to suppress file name handlers from magic
|
||
file names (*note (elisp)Magic File Names::).
|
||
|
||
*Note (elisp)File Name Expansion::.
|
||
|
||
-- Function: make-nearby-temp-file prefix &optional dir-flag suffix
|
||
This function is similar to ‘make-temp-file’, but it creates a
|
||
temporary file as close as possible to ‘default-directory’. If
|
||
PREFIX is a relative file name, and ‘default-directory’ is a remote
|
||
file name or located on a mounted file systems, the temporary file
|
||
is created in the directory returned by the function
|
||
‘temporary-file-directory’. Otherwise, the function
|
||
‘make-temp-file’ is used. PREFIX, DIR-FLAG and SUFFIX have the
|
||
same meaning as in ‘make-temp-file’.
|
||
|
||
(let ((default-directory "/ssh:remotehost:")) (make-nearby-temp-file
|
||
"foo")) ⇒ "/ssh:remotehost:/tmp/foo232J6v"
|
||
|
||
-- Variable: mounted-file-systems
|
||
A regular expression matching files names that are probably on a
|
||
mounted file system.
|
||
|
||
-- Function: temporary-file-directory
|
||
The directory for writing temporary files via
|
||
‘make-nearby-temp-file’. In case of a remote ‘default-directory’,
|
||
this is a directory for temporary files on that remote host. If
|
||
such a directory does not exist, or ‘default-directory’ ought to be
|
||
located on a mounted file system (see ‘mounted-file-systems’), the
|
||
function returns ‘default-directory’. For a non-remote and
|
||
non-mounted ‘default-directory’, the value of the variable
|
||
‘temporary-file-directory’ is returned.
|
||
|
||
*Note (elisp)Unique File Names::.
|
||
|
||
-- Macro: if-let* (bindings...) then &rest else
|
||
‘if-let*’ is mostly equivalent to ‘if-let’, with the exception that
|
||
the legacy ‘(if (VAR (test)) foo bar)’ syntax is not permitted.
|
||
|
||
-- Macro: when-let* (bindings...) then &rest else
|
||
‘when-let*’ is mostly equivalent to ‘when-let’, with the exception
|
||
that the legacy ‘(when-let (VAR (test)) foo bar)’ syntax is not
|
||
permitted.
|
||
|
||
-- Macro: and-let* (bindings...) &rest body
|
||
A combination of LET* and AND, analogous to ‘when-let*’. If all
|
||
BINDINGS are non-‘nil’ and BODY is ‘nil’, then the result of the
|
||
‘and-let*’ form will be the last value bound in BINDINGS.
|
||
|
||
**Please Note:** The implementation provided by Compat does not
|
||
include a bug that was observed with Emacs 26 (see
|
||
<https://debbugs.gnu.org/cgi/bugreport.cgi?bug=31840>).
|
||
|
||
-- Function: file-local-name filename
|
||
This function returns the _local part_ of FILENAME. This is the
|
||
part of the file’s name that identifies it on the remote host, and
|
||
is typically obtained by removing from the remote file name the
|
||
parts that specify the remote host and the method of accessing it.
|
||
For example:
|
||
|
||
(file-local-name "/ssh:USER@HOST:/foo/bar") ⇒
|
||
"/foo/bar"
|
||
|
||
For a remote FILENAME, this function returns a file name which
|
||
could be used directly as an argument of a remote process (*note
|
||
(elisp)Asynchronous Processes::, and *note (elisp)Synchronous
|
||
Processes::), and as the program to run on the remote host. If
|
||
FILENAME is local, this function returns it unchanged.
|
||
|
||
*Note (elisp)Magic File Names::.
|
||
|
||
-- Function: read-multiple-choice prompt choices
|
||
Ask user a multiple choice question. PROMPT should be a string
|
||
that will be displayed as the prompt.
|
||
|
||
CHOICES is an alist where the first element in each entry is a
|
||
character to be entered, the second element is a short name for the
|
||
entry to be displayed while prompting (if there’s room, it might be
|
||
shortened), and the third, optional entry is a longer explanation
|
||
that will be displayed in a help buffer if the user requests more
|
||
help.
|
||
|
||
See *note Reading One Event: (elisp)Reading One Event.
|
||
|
||
-- Function: image-property
|
||
Defined in ‘image.el’.
|
||
|
||
This function can also be used as a generalised variable.
|
||
|
||
-- Function: file-attribute-type
|
||
Return the field _type_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-link-number
|
||
Return the field _link-number_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-user-id
|
||
Return the field _user-id_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-group-id
|
||
Return the field _group-id_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-access-time
|
||
Return the field _access-time_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-modification-time
|
||
Return the field _modification-time_ as generated by
|
||
‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-status-change-time
|
||
Return the field _modification-time_ as generated by
|
||
‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-size
|
||
Return the field _size_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-modes
|
||
Return the field _modes_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-inode-number
|
||
Return the field _inode-number_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-device-number
|
||
Return the field _device-number_ as generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-attribute-collect attributes &rest attr-names
|
||
Filter the file attributes ATTRIBUTES, as generated by
|
||
‘file-attributes’, according to ATTR-NAMES.
|
||
|
||
Valid attribute names for ATTR-NAMES are: type, link-number,
|
||
user-id, group-id, access-time, modification-time,
|
||
status-change-time, size, modes, inode-number and device-number.
|
||
|
||
(file-attributes ".") ⇒ (t 1 1000 1000 (25329 18215 325481 96000) (25325 15364 530263 840000) (25325 15364 530263 840000) 788 "drwxr-xr-x" t 137819 40)
|
||
(file-attribute-collect (file-attributes ".") 'type 'modes
|
||
'inode-number) ⇒ (t "drwxr-xr-x" 137819)
|
||
|
||
2.2.2 Extended Definitions
|
||
--------------------------
|
||
|
||
These functions must be called explicitly via ‘compat-call’, since their
|
||
calling convention or behavior was extended in Emacs 26.1:
|
||
|
||
-- Function: compat-call make-temp-file prefix &optional dir-flag
|
||
suffix text
|
||
This function creates a temporary file and returns its name. Emacs
|
||
creates the temporary file’s name by adding to PREFIX some random
|
||
characters that are different in each Emacs job. The result is
|
||
guaranteed to be a newly created file, containing TEXT if that’s
|
||
given as a string and empty otherwise. On MS-DOS, this function
|
||
can truncate PREFIX to fit into the 8+3 file-name limits. If
|
||
PREFIX is a relative file name, it is expanded against
|
||
‘temporary-file-directory’.
|
||
|
||
The compatibility version adds support for handling the optional
|
||
argument TEXT.
|
||
|
||
(make-temp-file "foo")
|
||
⇒ "/tmp/foo232J6v"
|
||
|
||
When ‘make-temp-file’ returns, the file has been created and is
|
||
empty. At that point, you should write the intended contents into
|
||
the file.
|
||
|
||
If DIR-FLAG is non-‘nil’, ‘make-temp-file’ creates an empty
|
||
directory instead of an empty file. It returns the file name, not
|
||
the directory name, of that directory. *Note (elisp)Directory
|
||
Names::.
|
||
|
||
If SUFFIX is non-‘nil’, ‘make-temp-file’ adds it at the end of the
|
||
file name.
|
||
|
||
If TEXT is a string, ‘make-temp-file’ inserts it in the file.
|
||
|
||
To prevent conflicts among different libraries running in the same
|
||
Emacs, each Lisp program that uses ‘make-temp-file’ should have its
|
||
own PREFIX. The number added to the end of PREFIX distinguishes
|
||
between the same application running in different Emacs jobs.
|
||
Additional added characters permit a large number of distinct names
|
||
even in one Emacs job.
|
||
|
||
-- Function: compat-call assoc key alist &optional testfn
|
||
This function returns the first association for KEY in ALIST,
|
||
comparing KEY against the alist elements using TESTFN if it is a
|
||
function, and ‘equal’ otherwise (*note (elisp)Equality
|
||
Predicates::). If TESTFN is a function, it is called with two
|
||
arguments: the CAR of an element from ALIST and KEY. The function
|
||
returns ‘nil’ if no association in ALIST has a CAR equal to KEY, as
|
||
tested by TESTFN.
|
||
|
||
*Note (elisp)Association Lists::.
|
||
|
||
The compatibility version adds support for handling the optional
|
||
argument TESTFN.
|
||
|
||
-- Function: compat-call line-number-at-pos &optional pos absolute
|
||
This function returns the line number in the current buffer
|
||
corresponding to the buffer position POS. If POS is ‘nil’ or
|
||
omitted, the current buffer position is used. If ABSOLUTE is
|
||
‘nil’, the default, counting starts at ‘(point-min)’, so the value
|
||
refers to the contents of the accessible portion of the
|
||
(potentially narrowed) buffer. If ABSOLUTE is non-‘nil’, ignore
|
||
any narrowing and return
|
||
|
||
*Note (elisp)Text Lines::.
|
||
|
||
The compatibility version adds support for handling the optional
|
||
argument ABSOLUTE.
|
||
|
||
-- Function: compat-call alist-get key alist &optional default remove
|
||
testfn
|
||
*Note (elisp)Association Lists::. This function is similar to
|
||
‘assq’. It finds the first association ‘(KEY . VALUE)’ by
|
||
comparing KEY with ALIST elements, and, if found, returns the VALUE
|
||
of that association. If no association is found, the function
|
||
returns DEFAULT. Comparison of KEY against ALIST elements uses the
|
||
function specified by TESTFN, defaulting to ‘eq’.
|
||
|
||
*Note (elisp)Association Lists::.
|
||
|
||
The compatibility version handles the optional argument TESTFN. It
|
||
can also be used as a *note Generalized Variables:
|
||
(elisp)generalised variable.
|
||
|
||
-- Function: compat-call string-trim-left string &optional regexp
|
||
Remove the leading text that matches REGEXP from STRING. REGEXP
|
||
defaults to ‘[ \t\n\r]+’.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
The compatibility version handles the optional argument REGEXP.
|
||
|
||
-- Function: compat-call string-trim-right string &optional regexp
|
||
Remove the trailing text that matches REGEXP from STRING. REGEXP
|
||
defaults to ‘[ \t\n\r]+’.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
The compatibility version handles the optional argument REGEXP.
|
||
|
||
-- Function: compat-call string-trim string &optional trim-left
|
||
trim-right
|
||
Remove the leading text that matches TRIM-LEFT and trailing text
|
||
that matches TRIM-RIGHT from STRING. Both regexps default to ‘[
|
||
\t\n\r]+’.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
The compatibility version handles the optional arguments TRIM-LEFT
|
||
and TRIM-RIGHT.
|
||
|
||
2.2.3 Missing Definitions
|
||
-------------------------
|
||
|
||
Compat does not provide support for the following Lisp features
|
||
implemented in 26.1:
|
||
|
||
• The function ‘func-arity’.
|
||
• The function ‘secure-hash-algorithms’.
|
||
• The function ‘gnutls-available-p’.
|
||
• Support for records and record functions.
|
||
• The function ‘mapbacktrace’.
|
||
• The function ‘file-name-case-insensitive-p’.
|
||
• The additional elements of ‘parse-partial-sexp’.
|
||
• The function ‘add-variable-watcher’.
|
||
• The function ‘undo-amalgamate-change-group’.
|
||
• The function ‘char-from-name’
|
||
• Signalling errors when ‘length’ or ‘member’ deal with list cycles.
|
||
• The function ‘frame-list-z-order’.
|
||
• The function ‘frame-restack’.
|
||
• All changes related to ‘display-buffer’.
|
||
• The function ‘window-swap-states’.
|
||
• The function ‘string-version-lessp’.
|
||
• The ‘svg’ library.
|
||
• The ‘xdg’ library.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Emacs 27.1, Next: Emacs 28.1, Prev: Emacs 26.1, Up: Support
|
||
|
||
2.3 Emacs 27.1
|
||
==============
|
||
|
||
2.3.1 Added Definitions
|
||
-----------------------
|
||
|
||
The following functions and macros are implemented in Emacs 27.1. These
|
||
functions are made available by Compat on Emacs versions older than
|
||
27.1.
|
||
|
||
-- Function: major-mode-suspend
|
||
This function works like ‘fundamental-mode’, in that it kills all
|
||
buffer-local variables, but it also records the major mode in
|
||
effect, so that it could subsequently be restored. This function
|
||
and ‘major-mode-restore’ (described next) are useful when you need
|
||
to put a buffer under some specialized mode other than the one
|
||
Emacs chooses for it automatically, but would also like to be able
|
||
to switch back to the original mode later.
|
||
|
||
-- Function: major-mode-restore &optional avoided-modes
|
||
This function restores the major mode recorded by
|
||
‘major-mode-suspend’. If no major mode was recorded, this function
|
||
calls ‘normal-mode’, but tries to force it not to choose any modes
|
||
in AVOIDED-MODES, if that argument is non-‘nil’.
|
||
|
||
-- Function: ring-resize ring size
|
||
Set the size of RING to SIZE. If the new size is smaller, then the
|
||
oldest items in the ring are discarded.
|
||
|
||
-- Function: minibuffer-history-value
|
||
Return the value of the minibuffer input history list. If
|
||
MINIBUFFER-HISTORY-VARIABLE points to a buffer-local variable and
|
||
the minibuffer is active, return the buffer-local value for the
|
||
buffer that was current when the minibuffer was activated."
|
||
|
||
-- Macro: with-minibuffer-selected-window &rest body
|
||
Execute the forms in BODY from the minibuffer in its original
|
||
window. When used in a minibuffer window, select the window
|
||
selected just before the minibuffer was activated, and execute the
|
||
forms.
|
||
|
||
-- Function: read-char-from-minibuffer prompt &optional chars history
|
||
This function uses the minibuffer to read and return a single
|
||
character. Optionally, it ignores any input that is not a member
|
||
of CHARS, a list of accepted characters. The HISTORY argument
|
||
specifies the history list symbol to use; if it is omitted or
|
||
‘nil’, this function doesn’t use the history.
|
||
|
||
If you bind ‘help-form’ to a non-‘nil’ value while calling
|
||
‘read-char-from-minibuffer’, then pressing ‘help-char’ causes it to
|
||
evaluate ‘help-form’ and display the result.
|
||
|
||
-- Function: bignump object
|
||
This predicate tests whether its argument is a large integer, and
|
||
returns ‘t’ if so, ‘nil’ otherwise. Unlike small integers, large
|
||
integers can be ‘=’ or ‘eql’ even if they are not ‘eq’.
|
||
|
||
-- Function: fixnump object
|
||
This predicate tests whether its argument is a small integer, and
|
||
returns ‘t’ if so, ‘nil’ otherwise. Small integers can be compared
|
||
with ‘eq’.
|
||
|
||
-- Special Form: with-suppressed-warnings warnings body...
|
||
In execution, this is equivalent to ‘(progn BODY...)’, but the
|
||
compiler does not issue warnings for the specified conditions in
|
||
BODY. WARNINGS is an association list of warning symbols and
|
||
function/variable symbols they apply to. For instance, if you wish
|
||
to call an obsolete function called ‘foo’, but want to suppress the
|
||
compilation warning, say:
|
||
|
||
(with-suppressed-warnings ((obsolete foo))
|
||
(foo ...))
|
||
|
||
-- Function: proper-list-p object
|
||
This function returns the length of OBJECT if it is a proper list,
|
||
‘nil’ otherwise (*note (elisp)Cons Cells::). In addition to
|
||
satisfying ‘listp’, a proper list is neither circular nor dotted.
|
||
|
||
(proper-list-p '(a b c)) ⇒ 3
|
||
(proper-list-p '(a b . c)) ⇒ nil
|
||
|
||
*Note (elisp)List-related Predicates::.
|
||
|
||
-- Function: string-distance string1 string2 &optional bytecompare
|
||
This function returns the _Levenshtein distance_ between the source
|
||
string STRING1 and the target string STRING2. The Levenshtein
|
||
distance is the number of single-character changes—deletions,
|
||
insertions, or replacements—required to transform the source string
|
||
into the target string; it is one possible definition of the _edit
|
||
distance_ between strings.
|
||
|
||
Letter-case of the strings is significant for the computed
|
||
distance, but their text properties are ignored. If the optional
|
||
argument BYTECOMPARE is non-‘nil’, the function calculates the
|
||
distance in terms of bytes instead of characters. The byte-wise
|
||
comparison uses the internal Emacs representation of characters, so
|
||
it will produce inaccurate results for multibyte strings that
|
||
include raw bytes (*note (elisp)Text Representations::); make the
|
||
strings unibyte by encoding them (*note (elisp)Explicit Encoding::)
|
||
if you need accurate results with raw bytes.
|
||
|
||
*Note (elisp)Text Comparison::.
|
||
|
||
-- Macro: ignore-errors body...
|
||
This construct executes BODY, ignoring any errors that occur during
|
||
its execution. If the execution is without error, ‘ignore-errors’
|
||
returns the value of the last form in BODY; otherwise, it returns
|
||
‘nil’.
|
||
|
||
Here’s the example at the beginning of this subsection rewritten
|
||
using ‘ignore-errors’:
|
||
|
||
(ignore-errors (delete-file filename))
|
||
|
||
*Note (elisp)Handling Errors::.
|
||
|
||
-- Macro: dolist-with-progress-reporter (var count [result])
|
||
reporter-or-message body...
|
||
This is another convenience macro that works the same way as
|
||
‘dolist’ does, but also reports loop progress using the functions
|
||
described above. As in ‘dotimes-with-progress-reporter’,
|
||
‘reporter-or-message’ can be a progress reporter or a string. You
|
||
can rewrite the previous example with this macro as follows:
|
||
|
||
(dolist-with-progress-reporter (k (number-sequence 0 500)) "Collecting
|
||
some mana for Emacs..." (sit-for 0.01))
|
||
|
||
*Note (elisp)Progress::.
|
||
|
||
-- Function: flatten-tree tree
|
||
This function returns a “flattened” copy of TREE, that is, a list
|
||
containing all the non-‘nil’ terminal nodes, or leaves, of the tree
|
||
of cons cells rooted at TREE. Leaves in the returned list are in
|
||
the same order as in TREE.
|
||
|
||
(flatten-tree '(1 (2 . 3) nil (4 5 (6)) 7)) ⇒(1 2 3 4 5 6 7)
|
||
|
||
*Note (elisp)Building Lists::.
|
||
|
||
-- Function: xor condition1 condition2
|
||
This function returns the boolean exclusive-or of CONDITION1 and
|
||
CONDITION2. That is, ‘xor’ returns ‘nil’ if either both arguments
|
||
are ‘nil’, or both are non-‘nil’. Otherwise, it returns the value
|
||
of that argument which is non-‘nil’.
|
||
|
||
Note that in contrast to ‘or’, both arguments are always evaluated.
|
||
|
||
*Note (elisp)Combining Conditions::.
|
||
|
||
-- Variable: regexp-unmatchable
|
||
This variable contains a regexp that is guaranteed not to match any
|
||
string at all. It is particularly useful as default value for
|
||
variables that may be set to a pattern that actually matches
|
||
something.
|
||
|
||
*Note (elisp)Regexp Functions::
|
||
|
||
-- Function: decoded-time-second time
|
||
Return the SECONDS field of a ‘decoded-time’ record TIME. It can
|
||
also be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-minute time
|
||
Return the MINUTE field of a ‘decoded-time’ record TIME. It can
|
||
also be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-hour time
|
||
Return the HOUR field of a ‘decoded-time’ record TIME. It can also
|
||
be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-day time
|
||
Return the DAY field of a ‘decoded-time’ record TIME. It can also
|
||
be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-month time
|
||
Return the MONTH field of a ‘decoded-time’ record TIME. It can
|
||
also be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-year time
|
||
Return the YEAR field of a ‘decoded-time’ record TIME. It can also
|
||
be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-weekday time
|
||
Return the WEEKDAY field of a ‘decoded-time’ record TIME. It can
|
||
also be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: decoded-time-dst time
|
||
Return the DST (daylight saving time indicator) field of a
|
||
‘decoded-time’ record TIME. It can also be used as a *note
|
||
Generalized Variables: (elisp)generalised variable.
|
||
|
||
-- Function: decoded-time-zone time
|
||
Return the ZONE field of a ‘decoded-time’ record TIME. It can also
|
||
be used as a *note Generalized Variables: (elisp)generalised
|
||
variable.
|
||
|
||
-- Function: package-get-version
|
||
Return the version number of the package in which this is used.
|
||
|
||
-- Function: time-equal-p t1 t2
|
||
This returns ‘t’ if the two time values T1 and T2 are equal.
|
||
|
||
*Note (elisp)Time Calculations::.
|
||
|
||
-- Function: date-days-in-month year month
|
||
Return the number of days in MONTH in YEAR. For instance, February
|
||
2020 has 29 days.
|
||
|
||
*Note (elisp)Time Calculations::. This function requires the
|
||
‘time-date’ feature to be loaded.
|
||
|
||
-- Function: date-ordinal-to-time year ordinal
|
||
Convert a YEAR/ORDINAL to the equivalent decoded-time structure.
|
||
ORDINAL is the number of days since the start of the year, with
|
||
January 1st being 1.
|
||
|
||
*Note (elisp)Time Calculations::. This function requires the
|
||
‘time-date’ feature to be loaded.
|
||
|
||
-- User Option: exec-path
|
||
The value of this variable is a list of directories to search for
|
||
programs to run in subprocesses. Each element is either the name
|
||
of a directory (i.e., a string), or ‘nil’, which stands for the
|
||
default directory (which is the value of ‘default-directory’).
|
||
*Note executable-find: (elisp)Locating Files, for the details of
|
||
this search.
|
||
|
||
The value of ‘exec-path’ is used by ‘call-process’ and
|
||
‘start-process’ when the PROGRAM argument is not an absolute file
|
||
name.
|
||
|
||
Generally, you should not modify ‘exec-path’ directly. Instead,
|
||
ensure that your ‘PATH’ environment variable is set appropriately
|
||
before starting Emacs. Trying to modify ‘exec-path’ independently
|
||
of ‘PATH’ can lead to confusing results.
|
||
|
||
*Note (elisp)Subprocess Creation::.
|
||
|
||
-- Function: provided-mode-derived-p mode &rest modes
|
||
This function returns non-‘nil’ if MODE is derived from any of the
|
||
major modes given by the symbols MODES.
|
||
|
||
-- Function: file-size-human-readable-iec size
|
||
Human-readable string for SIZE bytes, using IEC prefixes.
|
||
|
||
-- Function: make-empty-file filename &optional parents
|
||
This function creates an empty file named FILENAME. As
|
||
‘make-directory’, this function creates parent directories if
|
||
PARENTS is non-‘nil’. If FILENAME already exists, this function
|
||
signals an error.
|
||
|
||
-- Function: text-property-search-forward prop &optional value
|
||
predicate not-current
|
||
Search for the next region that has text property PROP set to VALUE
|
||
according to PREDICATE.
|
||
|
||
This function is modeled after ‘search-forward’ and friends in that
|
||
it moves point, but it returns a structure that describes the match
|
||
instead of returning it in ‘match-beginning’ and friends.
|
||
|
||
If the text property can’t be found, the function returns ‘nil’.
|
||
If it’s found, point is placed at the end of the region that has
|
||
this text property match, and a ‘prop-match’ structure is returned.
|
||
|
||
PREDICATE can either be ‘t’ (which is a synonym for ‘equal’), ‘nil’
|
||
(which means “not equal”), or a predicate that will be called with
|
||
two parameters: The first is VALUE, and the second is the value of
|
||
the text property we’re inspecting.
|
||
|
||
If NOT-CURRENT, if point is in a region where we have a match, then
|
||
skip past that and find the next instance instead.
|
||
|
||
The ‘prop-match’ structure has the following accessors:
|
||
‘prop-match-beginning’ (the start of the match), ‘prop-match-end’
|
||
(the end of the match), and ‘prop-match-value’ (the value of
|
||
PROPERTY at the start of the match).
|
||
|
||
In the examples below, imagine that you’re in a buffer that looks
|
||
like this:
|
||
|
||
This is a bold and here's bolditalic and this is the end.
|
||
|
||
That is, the “bold” words are the ‘bold’ face, and the “italic”
|
||
word is in the ‘italic’ face.
|
||
|
||
With point at the start:
|
||
|
||
(while (setq match (text-property-search-forward 'face 'bold t))
|
||
(push (buffer-substring (prop-match-beginning match)
|
||
(prop-match-end match))
|
||
words))
|
||
|
||
This will pick out all the words that use the ‘bold’ face.
|
||
|
||
(while (setq match (text-property-search-forward 'face nil t))
|
||
(push (buffer-substring (prop-match-beginning match)
|
||
(prop-match-end match))
|
||
words))
|
||
|
||
This will pick out all the bits that have no face properties, which
|
||
will result in the list ‘("This is a " "and here's " "and this is
|
||
the end")’ (only reversed, since we used ‘push’).
|
||
|
||
(while (setq match (text-property-search-forward 'face nil nil))
|
||
(push (buffer-substring (prop-match-beginning match)
|
||
(prop-match-end match))
|
||
words))
|
||
|
||
This will pick out all the regions where ‘face’ is set to
|
||
something, but this is split up into where the properties change,
|
||
so the result here will be ‘("bold" "bold" "italic")’.
|
||
|
||
For a more realistic example where you might use this, consider
|
||
that you have a buffer where certain sections represent URLs, and
|
||
these are tagged with ‘shr-url’.
|
||
|
||
(while (setq match (text-property-search-forward 'shr-url nil nil))
|
||
(push (prop-match-value match) urls))
|
||
|
||
This will give you a list of all those URLs.
|
||
|
||
*Note (Property Search)elisp::.
|
||
|
||
-- Function: text-property-search-backward prop &optional value
|
||
predicate not-current
|
||
This is just like ‘text-property-search-forward’, but searches
|
||
backward instead. Point is placed at the beginning of the matched
|
||
region instead of the end, though.
|
||
|
||
*Note (Property Search)elisp::.
|
||
|
||
2.3.2 Extended Definitions
|
||
--------------------------
|
||
|
||
These functions must be called explicitly via ‘compat-call’, since their
|
||
calling convention or behavior was extended in Emacs 27.1:
|
||
|
||
-- Function: compat-call recenter &optional count redisplay
|
||
This function scrolls the text in the selected window so that point
|
||
is displayed at a specified vertical position within the window.
|
||
It does not move point with respect to the text.
|
||
|
||
*Note (elisp)Textual Scrolling::.
|
||
|
||
This compatibility version adds support for the optional argument
|
||
REDISPLAY.
|
||
|
||
-- Function: compat-call lookup-key keymap key &optional
|
||
accept-defaults
|
||
This function returns the definition of KEY in KEYMAP. If the
|
||
string or vector KEY is not a valid key sequence according to the
|
||
prefix keys specified in KEYMAP, it must be too long and have extra
|
||
events at the end that do not fit into a single key sequence. Then
|
||
the value is a number, the number of events at the front of KEY
|
||
that compose a complete key.
|
||
|
||
*Note (elisp)Low-Level Key Binding::.
|
||
|
||
This compatibility version allows for KEYMAP to be a list of
|
||
keymaps, instead of just a singular keymap.
|
||
|
||
-- Macro: compat-call setq-local &rest pairs
|
||
PAIRS is a list of variable and value pairs. This macro creates a
|
||
buffer-local binding in the current buffer for each of the
|
||
variables, and gives them a buffer-local value. It is equivalent
|
||
to calling ‘make-local-variable’ followed by ‘setq’ for each of the
|
||
variables. The variables should be unquoted symbols.
|
||
|
||
(setq-local var1 "value1"
|
||
var2 "value2")
|
||
|
||
*Note (elisp)Creating Buffer-Local::.
|
||
|
||
This compatibility version allows for more than one variable to be
|
||
set at once, as can be done with ‘setq’.
|
||
|
||
-- Function: compat-call regexp-opt strings &optional paren
|
||
This function returns an efficient regular expression that will
|
||
match any of the strings in the list STRINGS. This is useful when
|
||
you need to make matching or searching as fast as possible—for
|
||
example, for Font Lock mode.
|
||
|
||
*Note (elisp)Regexp Functions::.
|
||
|
||
The compatibility version of this functions handles the case where
|
||
STRINGS in an empty list. In that case, a regular expression is
|
||
generated that never matches anything (see ‘regexp-unmatchable’).
|
||
|
||
-- Function: compat-call file-size-human-readable file-size &optional
|
||
flavor space unit
|
||
Return a string with a human readable representation of FILE-SIZE.
|
||
|
||
The optional second argument FLAVOR controls the units and the
|
||
display format. If FLAVOR is...
|
||
|
||
• ‘si’, each kilobyte is 1000 bytes and the produced suffixes
|
||
are ‘k’, ‘M’, ‘G’, ‘T’, etc.
|
||
• ‘iec’, each kilobyte is 1024 bytes and the produced suffixes
|
||
are ‘KiB’, ‘MiB’, ‘GiB’, ‘TiB’, etc.
|
||
• ‘nil’ or omitted, each kilobyte is 1024 bytes and the produced
|
||
suffixes are ‘k’, ‘M’, ‘G’, ‘T’, etc.
|
||
|
||
The compatibility version handles the optional third (SPACE) and
|
||
forth (UNIT) arguments. The argument SPACE can be a string that is
|
||
placed between the number and the unit. The argument UNIT
|
||
determines the unit to use. By default it will be an empty string,
|
||
unless FLAVOR is ‘iec’, in which case it will be ‘B’.
|
||
|
||
-- Function: compat-call assoc-delete-all key alist &optional test
|
||
This function is like ‘assq-delete-all’ except that it accepts an
|
||
optional argument TEST, a predicate function to compare the keys in
|
||
ALIST. If omitted or ‘nil’, TEST defaults to ‘equal’. As
|
||
‘assq-delete-all’, this function often modifies the original list
|
||
structure of ALIST.
|
||
|
||
*Note (elisp)Association Lists::.
|
||
|
||
This compatibility version handles the optional third (TESTFN)
|
||
argument.
|
||
|
||
-- Function: compat-call executable-find program &optional remote
|
||
This function searches for the executable file of the named PROGRAM
|
||
and returns the absolute file name of the executable, including its
|
||
file-name extensions, if any. It returns ‘nil’ if the file is not
|
||
found. The function searches in all the directories in
|
||
‘exec-path’, and tries all the file-name extensions in
|
||
‘exec-suffixes’ (*note (elisp)Subprocess Creation::).
|
||
|
||
If REMOTE is non-‘nil’, and ‘default-directory’ is a remote
|
||
directory, PROGRAM is searched on the respective remote host.
|
||
|
||
*Note (elisp)Locating Files::.
|
||
|
||
This compatibility version adds support to handle the optional
|
||
second (REMOTE) argument.
|
||
|
||
2.3.3 Missing Definitions
|
||
-------------------------
|
||
|
||
Compat does not provide support for the following Lisp features
|
||
implemented in 27.1:
|
||
|
||
• The functions ‘base64url-encode-*’.
|
||
• The function ‘decoded-time-add’.
|
||
• The function ‘decoded-time-set-defaults’.
|
||
• The function ‘time-convert’.
|
||
• The macro ‘benchmark-progn’.
|
||
• Support for ‘condition-case’ to handle t.
|
||
• The function ‘file-system-info’.
|
||
• The function ‘group-name’.
|
||
• The function ‘face-extend-p’ and ‘set-face-extend’.
|
||
• Additional ‘format-spec’ modifiers.
|
||
• Support for additional body forms for
|
||
‘define-globalized-minor-mode’.
|
||
• The macro ‘with-connection-local-variables’ and related
|
||
functionality.
|
||
• The ‘iso8601’ library.
|
||
• The ‘exif’ library.
|
||
• The ‘image-converter’ library.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Emacs 28.1, Next: Emacs 29.1, Prev: Emacs 27.1, Up: Support
|
||
|
||
2.4 Emacs 28.1
|
||
==============
|
||
|
||
2.4.1 Added Definitions
|
||
-----------------------
|
||
|
||
The following functions and macros are implemented in Emacs 28.1. These
|
||
functions are made available by Compat on Emacs versions older than
|
||
28.1.
|
||
|
||
The ‘defcustom’ type ‘natnum’ introduced in Emacs 28.1 is made
|
||
available by Compat.
|
||
|
||
-- Function: process-lines-ignore-status program &rest args
|
||
This function is just like ‘process-lines’, but does not signal an
|
||
error if PROGRAM exits with a non-zero exit status.
|
||
|
||
-- Function: process-lines-handling-status program status-handler &rest
|
||
args
|
||
Execute PROGRAM with ARGS, returning its output as a list of lines.
|
||
If STATUS-HANDLER is non-nil, it must be a function with one
|
||
argument, which will be called with the exit status of the program
|
||
before the output is collected. If STATUS-HANDLER is nil, an error
|
||
is signaled if the program returns with a non-zero exit status.
|
||
|
||
-- Function: text-quoting-style
|
||
You should not read the value of the variable ‘text-quoting-style’
|
||
directly. Instead, use this function with the same name to
|
||
dynamically compute the correct quoting style on the current
|
||
terminal in the ‘nil’ case described above.
|
||
|
||
-- Function: string-search needle haystack &optional start-pos
|
||
Return the position of the first instance of NEEDLE in HAYSTACK,
|
||
both of which are strings. If START-POS is non-‘nil’, start
|
||
searching from that position in NEEDLE. Return ‘nil’ if no match
|
||
was found. This function only considers the characters in the
|
||
strings when doing the comparison; text properties are ignored.
|
||
Matching is always case-sensitive.
|
||
|
||
-- Function: length= sequence length
|
||
Return non-‘nil’ if the length of SEQUENCE is equal to LENGTH.
|
||
|
||
-- Function: length< sequence length
|
||
Return non-‘nil’ if SEQUENCE is shorter than LENGTH. This may be
|
||
more efficient than computing the length of SEQUENCE if SEQUENCE is
|
||
a long list.
|
||
|
||
-- Function: length> sequence length
|
||
Return non-‘nil’ if SEQUENCE is longer than LENGTH.
|
||
|
||
-- Function: file-name-concat directory &rest components
|
||
Concatenate COMPONENTS to DIRECTORY, inserting a slash before the
|
||
components if DIRECTORY or the preceding component didn’t end with
|
||
a slash.
|
||
|
||
(file-name-concat "/tmp" "foo") ⇒ "/tmp/foo"
|
||
|
||
A DIRECTORY or components that are ‘nil’ or the empty string are
|
||
ignored—they are filtered out first and do not affect the results
|
||
in any way.
|
||
|
||
This is almost the same as using ‘concat’, but DIRNAME (and the
|
||
non-final components) may or may not end with slash characters, and
|
||
this function will not double those characters.
|
||
|
||
-- Function: garbage-collect-maybe factor
|
||
Suggest to run garbage collection, if _enough_ data has been
|
||
allocated. This is determined by the positive numerical argument
|
||
FACTOR, that would proportionally increase the likelihood of
|
||
garbage collection taking place.
|
||
|
||
This compatibility function does nothing and ignores any
|
||
suggestion.
|
||
|
||
-- Function: string-replace from-string to-string in-string
|
||
This function replaces all occurrences of FROM-STRING with
|
||
TO-STRING in IN-STRING and returns the result. It may return one
|
||
of its arguments unchanged, a constant string or a new string.
|
||
Case is significant, and text properties are ignored.
|
||
|
||
-- Function: always &rest arguments
|
||
This function ignores any ARGUMENTS and returns ‘t’.
|
||
|
||
*Note (elisp)Calling Functions::.
|
||
|
||
-- Function: make-separator-line &optional length
|
||
Make a string appropriate for usage as a visual separator line. If
|
||
LENGTH is nil, use the window width.
|
||
|
||
-- Function: insert-into-buffer to-buffer &optional start end
|
||
This is like ‘insert-buffer-substring’, but works in the opposite
|
||
direction: The text is copied from the current buffer into
|
||
TO-BUFFER. The block of text is copied to the current point in
|
||
TO-BUFFER, and point (in that buffer) is advanced to after the end
|
||
of the copied text. Is ‘start’/‘end’ is ‘nil’, the entire text in
|
||
the current buffer is copied over.
|
||
|
||
*Note (elisp)Insertion::.
|
||
|
||
-- Function: replace-string-in-region regexp replacement &optional
|
||
start end
|
||
This function replaces all the occurrences of REGEXP with
|
||
REPLACEMENT in the region of buffer text between START and END;
|
||
START defaults to position of point, and END defaults to the last
|
||
accessible position of the buffer. The search for REGEXP is
|
||
case-sensitive, and REPLACEMENT is inserted without changing its
|
||
letter-case. The REPLACEMENT string can use the same special
|
||
elements starting with ‘\’ as ‘replace-match’ does. The function
|
||
returns the number of replaced occurrences, or ‘nil’ if REGEXP is
|
||
not found. The function preserves the position of point.
|
||
|
||
(replace-regexp-in-region "foo[ \t]+bar" "foobar")
|
||
*Note (elisp)Search and Replace::.
|
||
|
||
-- Function: replace-regexp-in-string string replacement &optional
|
||
start end
|
||
This function works similarly to ‘replace-regexp-in-region’, but
|
||
searches for, and replaces, literal STRINGs instead of regular
|
||
expressions.
|
||
|
||
*Note (elisp)Search and Replace::.
|
||
|
||
-- Function: buffer-local-boundp variable buffer
|
||
This returns non-‘nil’ if there’s either a buffer-local binding of
|
||
VARIABLE (a symbol) in buffer BUFFER, or VARIABLE has a global
|
||
binding.
|
||
|
||
*Note (elisp)Creating Buffer-Local::.
|
||
|
||
-- Macro: with-existing-directory body...
|
||
This macro ensures that ‘default-directory’ is bound to an existing
|
||
directory before executing BODY. If ‘default-directory’ already
|
||
exists, that’s preferred, and otherwise some other directory is
|
||
used. This macro can be useful, for instance, when calling an
|
||
external command that requires that it’s running in a directory
|
||
that exists. The chosen directory is not guaranteed to be
|
||
writable.
|
||
|
||
*Note (elisp)Testing Accessibility::.
|
||
|
||
-- Macro: dlet (bindings...) forms...
|
||
This special form is like ‘let’, but it binds all variables
|
||
dynamically. This is rarely useful—you usually want to bind normal
|
||
variables lexically, and special variables (i.e., variables that
|
||
are defined with ‘defvar’) dynamically, and this is what ‘let’
|
||
does.
|
||
|
||
‘dlet’ can be useful when interfacing with old code that assumes
|
||
that certain variables are dynamically bound (*note (elisp)Dynamic
|
||
Binding::), but it’s impractical to ‘defvar’ these variables.
|
||
‘dlet’ will temporarily make the bound variables special, execute
|
||
the forms, and then make the variables non-special again.
|
||
|
||
*Note (elisp)Local Variables::.
|
||
|
||
-- Function: ensure-list object
|
||
This function returns OBJECT as a list. If OBJECT is already a
|
||
list, the function returns it; otherwise, the function returns a
|
||
one-element list containing OBJECT.
|
||
|
||
This is usually useful if you have a variable that may or may not
|
||
be a list, and you can then say, for instance:
|
||
|
||
(dolist (elem (ensure-list foo))
|
||
(princ elem))
|
||
|
||
*Note (elisp)Building Lists::.
|
||
|
||
-- Function: string-clean-whitespace string
|
||
Clean up the whitespace in STRING by collapsing stretches of
|
||
whitespace to a single space character, as well as removing all
|
||
whitespace from the start and the end of STRING.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Function: string-fill string length
|
||
Attempt to Word-wrap STRING so that no lines are longer than
|
||
LENGTH. Filling is done on whitespace boundaries only. If there
|
||
are individual words that are longer than LENGTH, these will not be
|
||
shortened.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Function: string-lines string &optional omit-nulls
|
||
Split STRING into a list of strings on newline boundaries. If the
|
||
optional argument OMIT-NULLS is non-‘nil’, remove empty lines from
|
||
the results. Note that this function returns trailing newlines on
|
||
Emacs 28, use ‘compat-call string-lines’ instead if you want
|
||
consistent behavior.
|
||
|
||
-- Function: string-pad string length &optional padding start
|
||
Pad STRING to be of the given LENGTH using PADDING as the padding
|
||
character. PADDING defaults to the space character. If STRING is
|
||
longer than LENGTH, no padding is done. If START is ‘nil’ or
|
||
omitted, the padding is appended to the characters of STRING, and
|
||
if it’s non-‘nil’, the padding is prepended to STRING’s characters.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Function: string-chop-newline string
|
||
Remove the final newline, if any, from STRING.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Macro: named-let name bindings &rest body
|
||
This special form is a looping construct inspired from the Scheme
|
||
language. It is similar to ‘let’: It binds the variables in
|
||
BINDINGS, and then evaluates BODY. However, ‘named-let’ also binds
|
||
NAME to a local function whose formal arguments are the variables
|
||
in BINDINGS and whose body is BODY. This allows BODY to call
|
||
itself recursively by calling NAME, where the arguments passed to
|
||
NAME are used as the new values of the bound variables in the
|
||
recursive invocation.
|
||
|
||
Recursive calls to NAME that occur in _tail positions_ in BODY are
|
||
guaranteed to be optimized as _tail calls_, which means that they
|
||
will not consume any additional stack space no matter how deeply
|
||
the recursion runs. Such recursive calls will effectively jump to
|
||
the top of the loop with new values for the variables.
|
||
|
||
*Note (elisp)Local Variables::.
|
||
|
||
-- Function: file-name-with-extension filename extension
|
||
This function returns FILENAME with its extension set to EXTENSION.
|
||
A single leading dot in the EXTENSION will be stripped if there is
|
||
one. For example:
|
||
|
||
(file-name-with-extension "file" "el")
|
||
⇒ "file.el"
|
||
(file-name-with-extension "file" ".el")
|
||
⇒ "file.el"
|
||
(file-name-with-extension "file.c" "el")
|
||
⇒ "file.el"
|
||
|
||
Note that this function will error if FILENAME or EXTENSION are
|
||
empty, or if the FILENAME is shaped like a directory (i.e., if
|
||
‘directory-name-p’ returns non-‘nil’).
|
||
|
||
*Note File Name Components: (elisp)File Name Components.
|
||
|
||
-- Function: directory-empty-p directory
|
||
This utility function returns ‘t’ if given DIRECTORY is an
|
||
accessible directory and it does not contain any files, i.e., is an
|
||
empty directory. It will ignore ‘.’ and ‘..’ on systems that
|
||
return them as files in a directory.
|
||
|
||
Symbolic links to directories count as directories. See
|
||
FILE-SYMLINK-P to distinguish symlinks.
|
||
|
||
*Note (elisp)Contents of Directories::.
|
||
|
||
-- Function: format-prompt prompt default &rest format-args
|
||
Format PROMPT with default value DEFAULT according to the
|
||
‘minibuffer-default-prompt-format’ variable.
|
||
|
||
‘minibuffer-default-prompt-format’ is a format string (defaulting
|
||
to ‘" (default %s)"’ that says how the “default” bit in prompts
|
||
like ‘"Local filename (default somefile): "’ are to be formatted.
|
||
|
||
To allow the users to customize how this is displayed, code that
|
||
prompts the user for a value (and has a default) should look
|
||
something along the lines of this code snippet:
|
||
|
||
(read-file-name
|
||
(format-prompt "Local filename" file)
|
||
nil file)
|
||
|
||
If FORMAT-ARGS is ‘nil’, PROMPT is used as a literal string. If
|
||
FORMAT-ARGS is non-‘nil’, PROMPT is used as a format control
|
||
string, and PROMPT and FORMAT-ARGS are passed to ‘format’ (*note
|
||
(elisp)Formatting Strings::).
|
||
|
||
‘minibuffer-default-prompt-format’ can be ‘""’, in which case no
|
||
default values are displayed.
|
||
|
||
If DEFAULT is ‘nil’, there is no default value, and therefore no
|
||
“default value” string is included in the result value. If DEFAULT
|
||
is a non-‘nil’ list, the first element of the list is used in the
|
||
prompt.
|
||
|
||
*Note (elisp)Text from Minibuffer::.
|
||
|
||
-- Function: thing-at-mouse event thing &optional no-properties
|
||
Mouse-EVENT equivalent of ‘thing-at-point’. THING can be ‘symbol’,
|
||
‘list’, ‘sexp’, ‘filename’, ‘url’, ... among other things.
|
||
|
||
When NO-PROPERTIES has a non-‘nil’ value, any text properties that
|
||
might have been present in the buffer are stripped away.
|
||
|
||
-- Function: bounds-of-thing-at-mouse event thing
|
||
Determine start and end locations for THING at mouse click given by
|
||
EVENT. Like ‘bounds-of-thing-at-point’, but tries to use the
|
||
position in EVENT where the mouse button is clicked to find the
|
||
thing nearby.
|
||
|
||
-- Function: mark-thing-at-mouse click thing
|
||
Activate the region around THING found near the mouse CLICK.
|
||
|
||
-- Function: macroexp-file-name
|
||
Return the name of the file in which the code is currently being
|
||
evaluated, or ‘nil’ if it cannot be determined.
|
||
|
||
-- Function: macroexp-warn-and-return msg form &optional category
|
||
compile-only arg
|
||
Return code equivalent to ‘form’ labeled with warning ‘msg’.
|
||
|
||
-- Macro: with-environment-variables variables body...
|
||
This macro sets the environment variables according to VARIABLES
|
||
temporarily when executing BODY. The previous values are restored
|
||
when the form finishes. The argument VARIABLES should be a list of
|
||
pairs of strings of the form ‘(VAR VALUE)’, where VAR is the name
|
||
of the environment variable and VALUE is that variable’s value.
|
||
|
||
(with-environment-variables (("LANG" "C")
|
||
("LANGUAGE" "en_US:en"))
|
||
(call-process "ls" nil t))
|
||
|
||
*Note System Environment: (elisp)System Environment.
|
||
|
||
-- Function: color-dark-p rgb
|
||
Whether RGB is more readable against white than black. RGB is a
|
||
3-element list (R G B), each component in the range [0,1]. This
|
||
predicate can be used both for determining a suitable (black or
|
||
white) contrast color with RGB as background and as foreground.
|
||
|
||
-- Function: color-values-from-color-spec spec
|
||
Convert the textual color specification SPEC to a color triple
|
||
‘(RED GREEN blue)’. Each of RED, GREEN and ‘blue’ is a integer
|
||
value between 0 and 65535.
|
||
|
||
The specification SPEC can be one of the following
|
||
• ‘#RGB’, where R, G and B are hex numbers of equal length, 1-4
|
||
digits each.
|
||
• ‘rgb:R/G/B’, where R, G, and B are hex numbers, 1-4 digits
|
||
each.
|
||
• ‘rgbi:R/G/B’, where R, G and B are floating-point numbers in
|
||
[0,1].
|
||
|
||
-- Function: file-modes-number-to-symbolic modes
|
||
This function converts a numeric file mode specification in MODES
|
||
into the equivalent symbolic form.
|
||
|
||
*Note Changing Files: (elisp)Changing Files.
|
||
|
||
-- Function: file-backup-file-names filename
|
||
This function returns a list of all the backup file names for
|
||
FILENAME, or ‘nil’ if there are none. The files are sorted by
|
||
modification time, descending, so that the most recent files are
|
||
first.
|
||
|
||
*Note (elisp)Backup Names::.
|
||
|
||
-- Function: make-lock-file-name filename
|
||
Return a string containing a lock file name for FILENAME, obeying
|
||
‘lock-file-name-transforms’.
|
||
|
||
-- Function: decoded-time-period time
|
||
Interpret TIME as a period and return its length in seconds. For
|
||
computational purposes, years are 365 days long and months are 30
|
||
days long.
|
||
|
||
-- Function: subr-primitive-p object
|
||
Return ‘t’ if OBJECT is a primitive, built-in function. On systems
|
||
with native compilation ‘subrp’ does not distinguish between
|
||
built-in functions and functions that have been compiled. If
|
||
native compilation is not available, this function behaves
|
||
identically to ‘subrp’.
|
||
|
||
-- Function: subr-native-elisp-p object
|
||
Return ‘t’ if OBJECT if the object is native compiled lisp. If
|
||
native compilation is not available, this function always returns
|
||
‘nil’.
|
||
|
||
-- Macro: with-window-non-dedicated window &rest body
|
||
Evaluate BODY with WINDOW temporarily made non-dedicated. If
|
||
WINDOW is nil, use the selected window. Return the value of the
|
||
last form in BODY.
|
||
|
||
2.4.2 Extended Definitions
|
||
--------------------------
|
||
|
||
These functions must be called explicitly via ‘compat-call’, since their
|
||
calling convention or behavior was extended in Emacs 28.1:
|
||
|
||
-- Function: compat-call string-width string &optional from to
|
||
This function returns the width in columns of the string STRING, if
|
||
it were displayed in the current buffer and the selected window.
|
||
Optional arguments FROM and TO specify the substring of STRING to
|
||
consider, and are interpreted as in ‘substring’ (*note
|
||
(elisp)Creating Strings::).
|
||
|
||
The return value is an approximation: it only considers the values
|
||
returned by ‘char-width’ for the constituent characters, always
|
||
takes a tab character as taking ‘tab-width’ columns, ignores
|
||
display properties and fonts, etc.
|
||
|
||
*Note (elisp)Size of Displayed Text::.
|
||
|
||
This compatibility version handles the optional arguments FROM and
|
||
TO.
|
||
|
||
-- Function: compat-call count-windows
|
||
Return the number of live windows on the selected frame.
|
||
|
||
The optional argument MINIBUF specifies whether the minibuffer
|
||
window is included in the count.
|
||
|
||
If ALL-FRAMES is non-‘nil’, count the windows in all frames instead
|
||
just the selected frame.
|
||
|
||
This compatibility version handles the optional argument
|
||
ALL-FRAMES.
|
||
|
||
2.4.3 Missing Definitions
|
||
-------------------------
|
||
|
||
Compat does not provide support for the following Lisp features
|
||
implemented in 28.1:
|
||
|
||
• Support for ‘interactive’ or ‘declare’ to list applicable modes.
|
||
• Support for ‘:interactive’ argument to ‘define-minor-mode’ and
|
||
‘define-derived-mode’.
|
||
• Support for ‘:predicate’ argument to
|
||
‘define-globalized-minor-mode’.
|
||
• Support for the ‘:success’ handler of ‘condition-case’.
|
||
• The function ‘benchmark-call’.
|
||
• Additional Edebug keywords.
|
||
• The libjansson JSON APIs, e.g., ‘json-parse-string’.
|
||
• The macro ‘pcase-setq’.
|
||
• The function ‘custom-add-choice’.
|
||
• The functions ‘dom-print’ and ‘dom-remove-attribute’.
|
||
• The function ‘dns-query-asynchronous’.
|
||
• The function ‘get-locale-names’.
|
||
• The functions ‘mail-header-parse-addresses-lax’ and
|
||
‘mail-header-parse-address-lax’.
|
||
• The function ‘num-processors’.
|
||
• The function ‘object-intervals’.
|
||
• The function ‘require-theme’.
|
||
• The function ‘syntax-class-to-char’.
|
||
• The function ‘path-separator’.
|
||
• The function ‘null-device’.
|
||
• The function ‘macroexp-compiling-p’.
|
||
• The function ‘split-string-shell-command’.
|
||
• The function ‘string-limit’.
|
||
• The functions ‘innermost-minibuffer-p’ and
|
||
‘minibuffer-innermost-command-loop-p’.
|
||
• The function ‘max-mini-window-lines’.
|
||
• The function ‘lock-file’ and ‘unlock-file’.
|
||
• The ‘multisession’ library.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Emacs 29.1, Prev: Emacs 28.1, Up: Support
|
||
|
||
2.5 Emacs 29.1
|
||
==============
|
||
|
||
2.5.1 Added Definitions
|
||
-----------------------
|
||
|
||
The following functions and macros are implemented in Emacs 29.1. These
|
||
functions are made available by Compat on Emacs versions older than
|
||
29.1. Note that due to upstream changes, it might happen that there
|
||
will be the need for changes, so use these functions with care.
|
||
|
||
The ‘defcustom’ type ‘key’ introduced in Emacs 28.1 is made available
|
||
by Compat.
|
||
|
||
-- Function: count-sentences start end
|
||
Count sentences in current buffer from START to END.
|
||
|
||
-- Function: readablep object
|
||
This predicate says whether OBJECT has “readable syntax”, i.e., it
|
||
can be written out and then read back by the Emacs Lisp reader. If
|
||
it can’t, this function returns ‘nil’; if it can, this function
|
||
returns a printed representation (via ‘prin1’).
|
||
|
||
-- Function: substitute-quotes string
|
||
This function works like ‘substitute-command-keys’, but only
|
||
replaces quote characters.
|
||
|
||
-- Function: get-scratch-buffer-create
|
||
Return the *scratch* buffer, creating a new one if needed.
|
||
|
||
-- Function: use-region-noncontiguous-p
|
||
Return non-nil for a non-contiguous region if ‘use-region-p’.
|
||
|
||
-- Function: use-region-end
|
||
Return the end of the region if ‘use-region-p’.
|
||
|
||
-- Function: use-region-beginning
|
||
Return the start of the region if ‘use-region-p’.
|
||
|
||
-- Macro: buffer-local-set-state variable value...
|
||
Minor modes often set buffer-local variables that affect some
|
||
features in Emacs. When a minor mode is switched off, the mode is
|
||
expected to restore the previous state of these variables. This
|
||
convenience macro helps with doing that: It works much like
|
||
‘setq-local’, but returns an object that can be used to restore
|
||
these values back to their previous values/states (using the
|
||
companion function ‘buffer-local-restore-state’).
|
||
|
||
-- Function: delete-line
|
||
Delete the current line.
|
||
|
||
-- Function: list-of-strings-p object
|
||
Return ‘t’ if OBJECT is ‘nil’ or a list of strings.
|
||
|
||
-- Function: plistp object
|
||
Non-nil if and only if OBJECT is a valid plist.
|
||
|
||
-- Macro: with-memoization PLACE CODE...
|
||
This macro provides a simple way to do memoization. CODE is
|
||
evaluated and then stashed in PLACE. If PLACE’s value is
|
||
non-‘nil’, return that value instead of evaluating CODE.
|
||
|
||
-- Special Form: with-restriction start end [:label label] body
|
||
This special form saves the current bounds of the accessible
|
||
portion of the buffer, sets the accessible portion to start at
|
||
START and end at END, evaluates the BODY forms, and restores the
|
||
saved bounds. In that case it is equivalent to
|
||
|
||
(save-restriction
|
||
(narrow-to-region start end)
|
||
body)
|
||
|
||
When the optional argument LABEL, a symbol, is present, the
|
||
narrowing is “labeled”. A labeled narrowing differs from a
|
||
non-labeled one in several ways:
|
||
|
||
• During the evaluation of the BODY form, ‘narrow-to-region’ and
|
||
‘widen’ can be used only within the START and END limits.
|
||
|
||
• To lift the restriction introduced by ‘with-restriction’ and
|
||
gain access to other portions of the buffer, use
|
||
‘without-restriction’ with the same LABEL argument. (Another
|
||
way to gain access to other portions of the buffer is to use
|
||
an indirect buffer (*note (elisp)Indirect Buffers::).)
|
||
|
||
• Labeled narrowings can be nested.
|
||
|
||
• Labeled narrowings can only be used in Lisp programs: they are
|
||
never visible on display, and never interfere with narrowings
|
||
set by the user.
|
||
|
||
If you use ‘with-restriction’ with the optional LABEL argument, we
|
||
recommend documenting the LABEL in the doc strings of the functions
|
||
which use it, so that other Lisp programs your code calls could
|
||
lift the labeled narrowing if and when it needs.
|
||
|
||
-- Special Form: without-restriction [:label label] body
|
||
This special form saves the current bounds of the accessible
|
||
portion of the buffer, widens the buffer, evaluates the BODY forms,
|
||
and restores the saved bounds. In that case it is equivalent to
|
||
|
||
(save-restriction
|
||
(widen)
|
||
body)
|
||
|
||
When the optional argument LABEL is present, the narrowing set by
|
||
‘with-restriction’ with the same LABEL argument is lifted.
|
||
|
||
-- Function: pos-bol &optional count
|
||
Like ‘line-beginning-position’, but ignores fields (and is more
|
||
efficient).
|
||
|
||
-- Function: pos-eol &optional count
|
||
Like ‘line-end-position’, but ignores fields (and is more
|
||
efficient).
|
||
|
||
-- Macro: with-delayed-message (timeout message) body...
|
||
Sometimes it’s unclear whether an operation will take a long time
|
||
to execute or not, or it can be inconvenient to implement a
|
||
progress reporter. This macro can be used in those situations.
|
||
|
||
(with-delayed-message (2 (format "Gathering data for %s" entry))
|
||
(setq data (gather-data entry)))
|
||
|
||
In this example, if the body takes more than two seconds to
|
||
execute, the message will be displayed. If it takes a shorter time
|
||
than that, the message won’t be displayed. In either case, the
|
||
body is evaluated as normally, and the return value of the final
|
||
element in the body is the return value of the macro.
|
||
|
||
The MESSAGE element is evaluated before BODY, and is always
|
||
evaluated, whether the message is displayed or not.
|
||
|
||
-- Function: funcall-with-delayed-message timeout message function
|
||
Like ‘funcall’, but display MESSAGE if FUNCTION takes longer than
|
||
TIMEOUT. TIMEOUT is a number of seconds, and can be an integer or
|
||
a floating point number.
|
||
|
||
If FUNCTION takes less time to execute than TIMEOUT seconds,
|
||
MESSAGE is not displayed.
|
||
|
||
-- Function: buttonize string callback &optional data help-echo
|
||
Sometimes it’s more convenient to make a string into a button
|
||
without inserting it into a buffer immediately, for instance when
|
||
creating data structures that may then, later, be inserted into a
|
||
buffer. This function makes STRING into such a string, and
|
||
CALLBACK will be called when the user clicks on the button. The
|
||
optional DATA parameter will be used as the parameter when CALLBACK
|
||
is called. If ‘nil’, the button is used as the parameter instead.
|
||
|
||
-- Function: buttonize-region start end callback &optional data
|
||
help-echo
|
||
Make the region between START and END into a button. When clicked,
|
||
CALLBACK will be called with the DATA as the function argument. If
|
||
DATA isn’t present (or is nil), the button itself will be used
|
||
instead as the function argument. If HELP-ECHO, use that as the
|
||
help-echo property.
|
||
|
||
-- Function: get-display-property position prop &optional object
|
||
properties
|
||
This convenience function can be used to get a specific display
|
||
property, no matter whether the ‘display’ property is a vector, a
|
||
list or a simple property. This is like ‘get-text-property’ (*note
|
||
Examining Properties: (elisp)Examining Properties.), but works on
|
||
the ‘display’ property only.
|
||
|
||
POSITION is the position in the buffer or string to examine, and
|
||
PROP is the ‘display’ property to return. The optional OBJECT
|
||
argument should be either a string or a buffer, and defaults to the
|
||
current buffer. If the optional PROPERTIES argument is non-‘nil’,
|
||
it should be a ‘display’ property, and in that case, POSITION and
|
||
OBJECT are ignored. (This can be useful if you’ve already gotten
|
||
the ‘display’ property with ‘get-char-property’, for instance
|
||
(*note Examining Properties: (elisp)Examining Properties.).
|
||
|
||
-- Function: add-display-text-property start end prop value &optional
|
||
object
|
||
Add display property PROP with VALUE to the text from START to END.
|
||
If any text in the region has a non-nil ‘display’ property, those
|
||
properties are retained.
|
||
|
||
If OBJECT is non-‘nil’, it should be a string or a buffer. If
|
||
‘nil’, this defaults to the current buffer.
|
||
|
||
-- Function: take n list
|
||
This function returns the N first elements of LIST. Essentially,
|
||
it returns the part of LIST that ‘nthcdr’ skips.
|
||
|
||
‘take’ returns LIST if shorter than N elements; it returns ‘nil’ if
|
||
N is zero or negative.
|
||
|
||
(take 3 '(a b c d))
|
||
⇒ (a b c)
|
||
(take 10 '(a b c d))
|
||
⇒ (a b c d)
|
||
(take 0 '(a b c d))
|
||
⇒ nil
|
||
|
||
-- Function: ntake n list
|
||
This is a version of ‘take’ that works by destructively modifying
|
||
the list structure of the argument. That makes it faster, but the
|
||
original value of LIST may be lost.
|
||
|
||
‘ntake’ returns LIST unmodified if shorter than N elements; it
|
||
returns ‘nil’ if N is zero or negative. Otherwise, it returns LIST
|
||
truncated to its first N elements.
|
||
|
||
This means that it is usually a good idea to use the return value
|
||
and not just rely on the truncation effect unless N is known to be
|
||
positive.
|
||
|
||
-- Function: compiled-function-p object
|
||
This function returns ‘t’ if OBJECT is a function object that is
|
||
not in the form of ELisp source code but something like machine
|
||
code or byte code instead. More specifically it returns ‘t’ if the
|
||
function is built-in, or byte-compiled, or natively-compiled, or a
|
||
function loaded from a dynamic module.
|
||
|
||
-- Function: function-alias-p object &optional noerror
|
||
Checks whether OBJECT is a function alias. If it is, it returns a
|
||
list of symbols representing the function alias chain, else ‘nil’.
|
||
For instance, if ‘a’ is an alias for ‘b’, and ‘b’ is an alias for
|
||
‘c’:
|
||
|
||
(function-alias-p 'a)
|
||
⇒ (b c)
|
||
|
||
If there’s a loop in the definitions, an error will be signalled.
|
||
If NOERROR is non-‘nil’, the non-looping parts of the chain is
|
||
returned instead.
|
||
|
||
-- Function: string-equal-ignore-case string1 string2
|
||
‘string-equal-ignore-case’ compares strings ignoring case
|
||
differences, like ‘char-equal’ when ‘case-fold-search’ is ‘t’.
|
||
|
||
*Note (elisp)Text Comparison::.
|
||
|
||
-- Function: string-split string &optional separators omit-nulls trim
|
||
‘string-split’ is an alias for the function ‘split-string’. The
|
||
name follows the convention of other string functions.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Function: buffer-match-p condition buffer-or-name &optional arg
|
||
This function checks if a buffer designated by ‘buffer-or-name’
|
||
satisfies a ‘condition’. Optional third argument ARG is passed to
|
||
the predicate function in CONDITION. A condition can be one of the
|
||
following:
|
||
• A string, interpreted as a regular expression. The buffer
|
||
satisfies the condition if the regular expression matches the
|
||
buffer name.
|
||
• A predicate function, which should return non-‘nil’ if the
|
||
buffer matches. If the function expects one argument, it is
|
||
called with BUFFER-OR-NAME as the argument; if it expects 2
|
||
arguments, the first argument is BUFFER-OR-NAME and the second
|
||
is ARG (or ‘nil’ if ARG is omitted).
|
||
• A cons-cell ‘(OPER . EXPR)’ where OPER is one of
|
||
‘not’
|
||
Satisfied if EXPR doesn’t satisfy ‘buffer-match-p’ with
|
||
the same buffer and ‘arg’.
|
||
‘or’
|
||
Satisfied if EXPR is a list and _any_ condition in EXPR
|
||
satisfies ‘buffer-match-p’, with the same buffer and
|
||
‘arg’.
|
||
‘and’
|
||
Satisfied if EXPR is a list and _all_ conditions in EXPR
|
||
satisfy ‘buffer-match-p’, with the same buffer and ‘arg’.
|
||
‘derived-mode’
|
||
Satisfied if the buffer’s major mode derives from EXPR.
|
||
‘major-mode’
|
||
Satisfied if the buffer’s major mode is equal to EXPR.
|
||
Prefer using ‘derived-mode’ instead when both can work.
|
||
• t Satisfied by any buffer. A convenient alternative to ‘""’
|
||
(empty string), ‘(and)’ (empty conjunction) or ‘always’.
|
||
|
||
*Note (elisp)Buffer List::.
|
||
|
||
-- Function: match-buffers condition &optional buffers arg
|
||
This function returns a list of all buffers that satisfy a
|
||
‘condition’, as defined for ‘buffer-match-p’. By default all
|
||
buffers are considered, but this can be restricted via the second
|
||
optional ‘buffer-list’ argument. Optional third argument ARG will
|
||
be used by CONDITION in the same way as ‘buffer-match-p’ does.
|
||
|
||
*Note (elisp)Buffer List::.
|
||
|
||
-- Function: string-glyph-split string
|
||
When character compositions are in effect, sequence of characters
|
||
can be composed for display to form _grapheme clusters_, for
|
||
example to display accented characters, or ligatures, or Emoji, or
|
||
when complex text shaping requires that for some scripts. When
|
||
that happens, characters no longer map in a simple way to display
|
||
columns, and display layout decisions with such strings, such as
|
||
truncating too wide strings, can be a complex job. This function
|
||
helps in performing suvh jobs: it splits up its argument STRING
|
||
into a list of substrings, where each substring produces a single
|
||
grapheme cluster that should be displayed as a unit. Lisp programs
|
||
can then use this list to construct visually-valid substrings of
|
||
STRING which will look correctly on display, or compute the width
|
||
of any substring of STRING by adding the width of its constituents
|
||
in the returned list, etc.
|
||
|
||
For instance, if you want to display a string without the first
|
||
glyph, you can say:
|
||
|
||
(apply #'insert (cdr (string-glyph-split string))))
|
||
|
||
*Note (elisp)Size of Displayed Text::.
|
||
|
||
-- Macro: with-buffer-unmodified-if-unchanged &rest body...
|
||
Evaluate BODY like ‘progn’, but change buffer-modified status only
|
||
if buffer text changes. If the buffer was unmodified before
|
||
execution of BODY, and buffer text after execution of BODY is
|
||
identical to what it was before, ensure that buffer is still marked
|
||
unmodified afterwards.
|
||
|
||
Note that only changes in the raw byte sequence of the buffer text,
|
||
as stored in the internal representation, are monitored for the
|
||
purpose of detecting the lack of changes in buffer text. Any other
|
||
changes that are normally perceived as "buffer modifications", such
|
||
as changes in text properties, ‘buffer-file-coding-system’, buffer
|
||
multibyteness, etc. – will not be noticed, and the buffer will
|
||
still be marked unmodified, effectively ignoring those changes.
|
||
|
||
-- Function: file-attribute-file-identifier
|
||
Return the fields ‘(inodenum device)’ as a list from attributes
|
||
generated by ‘file-attributes’.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: file-name-split filename
|
||
This function splits a file name into its components, and can be
|
||
thought of as the inverse of ‘string-join’ with the appropriate
|
||
directory separator. For example,
|
||
|
||
(file-name-split "/tmp/foo.txt")
|
||
⇒ ("" "tmp" "foo.txt")
|
||
(string-join (file-name-split "/tmp/foo.txt") "/")
|
||
⇒ "/tmp/foo.txt"
|
||
|
||
-- Function: file-name-parent-directory filename
|
||
This function returns the directory name of the parent directory of
|
||
FILENAME. If FILENAME is at the root directory of the filesystem,
|
||
it returns ‘nil’. A relative FILENAME is assumed to be relative to
|
||
‘default-directory’, and the return value will also be relative in
|
||
that case. If the return value is non-‘nil’, it ends in a slash.
|
||
|
||
*Note (elisp)Directory Names::.
|
||
|
||
-- Function: file-has-changed-p file &optional tag
|
||
This function returns non-‘nil’ if the time stamp of FILENAME has
|
||
changed since the last call. When called for the first time for
|
||
some FILENAME, it records the last modification time and size of
|
||
the file, and returns non-‘nil’ when FILENAME exists. Thereafter,
|
||
when called for the same FILENAME, it compares the current time
|
||
stamp and size with the recorded ones, and returns non-‘nil’ only
|
||
if either the time stamp or the size (or both) are different. This
|
||
is useful when a Lisp program wants to re-read a file whenever it
|
||
changes. With an optional argument TAG, which must be a symbol,
|
||
the size and modification time comparisons are limited to calls
|
||
with the same tag.
|
||
|
||
*Note (elisp)File Attributes::.
|
||
|
||
-- Function: directory-abbrev-make-regexp directory
|
||
Create a regexp to match DIRECTORY for ‘directory-abbrev-alist’.
|
||
|
||
-- Function: directory-abbrev-apply filename
|
||
Apply the abbreviations in ‘directory-abbrev-alist’ to FILENAME.
|
||
Note that when calling this, you should set ‘case-fold-search’ as
|
||
appropriate for the filesystem used for FILENAME.
|
||
|
||
-- Function: key-valid-p keys
|
||
Say whether KEYS is a valid key. A key is a string consisting of
|
||
one or more key strokes. The key strokes are separated by single
|
||
space characters.
|
||
|
||
Each key stroke is either a single character, or the name of an
|
||
event, surrounded by angle brackets. In addition, any key stroke
|
||
may be preceded by one or more modifier keys. Finally, a limited
|
||
number of characters have a special shorthand syntax.
|
||
|
||
Here’s some example key sequences.
|
||
|
||
‘f’
|
||
The key ‘f’.
|
||
‘S o m’
|
||
A three key sequence of the keys ‘S’, ‘o’ and ‘m’.
|
||
‘C-c o’
|
||
A two key sequence of the keys ‘c’ with the control modifier
|
||
and then the key ‘o’.
|
||
‘H-<left>’
|
||
The key named "left" with the hyper modifier.
|
||
‘M-RET’
|
||
The "return" key with a meta modifier.
|
||
‘C-M-<space>’
|
||
The "space" key with both the control and meta modifiers.
|
||
|
||
These are the characters that have shorthand syntax: ‘NUL’, ‘RET’,
|
||
‘TAB’, ‘LFD’, ‘ESC’, ‘SPC’, ‘DEL’.
|
||
|
||
Modifiers have to be specified in this order
|
||
Alt (A)-Control (C)-Hyper (H)-Meta (M)-Shift (s)-Super (s)
|
||
|
||
-- Function: key-parse keys
|
||
Convert KEYS to the internal Emacs key representation. See
|
||
‘key-valid-p’ for a description of valid key sequences. Examples
|
||
include ‘f’, ‘C-c C-c’, ‘H-<left>’, ‘M-RET’ or ‘C-M-<return>’.
|
||
|
||
-- Function: keymap-set keymap key definition
|
||
This function sets the binding for KEY in KEYMAP. (If KEY is more
|
||
than one event long, the change is actually made in another keymap
|
||
reached from KEYMAP.) The argument BINDING can be any Lisp object,
|
||
but only certain types are meaningful. (For a list of meaningful
|
||
types, see *note (elisp)Key Lookup::.) The value returned by
|
||
‘keymap-set’ is BINDING.
|
||
|
||
If KEY is ‘<t>’, this sets the default binding in KEYMAP. When an
|
||
event has no binding of its own, the Emacs command loop uses the
|
||
keymap’s default binding, if there is one.
|
||
|
||
Every prefix of KEY must be a prefix key (i.e., bound to a keymap)
|
||
or undefined; otherwise an error is signaled. If some prefix of
|
||
KEY is undefined, then ‘keymap-set’ defines it as a prefix key so
|
||
that the rest of KEY can be defined as specified.
|
||
|
||
If there was previously no binding for KEY in KEYMAP, the new
|
||
binding is added at the beginning of KEYMAP. The order of bindings
|
||
in a keymap makes no difference for keyboard input, but it does
|
||
matter for menu keymaps (*note (elisp)Menu Keymaps::).
|
||
|
||
*Note (elisp)Changing Key Bindings::.
|
||
|
||
-- Function: keymap-global-set key command
|
||
This function sets the binding of KEY in the current global map to
|
||
BINDING.
|
||
|
||
(keymap-global-set KEY BINDING)
|
||
≡
|
||
(keymap-set (current-global-map) KEY BINDING)
|
||
|
||
*Note (elisp)Key Binding Commands::.
|
||
|
||
-- Function: keymap-local-set key command
|
||
This function sets the binding of KEY in the current local keymap
|
||
to BINDING.
|
||
|
||
(keymap-local-set KEY BINDING)
|
||
≡
|
||
(keymap-set (current-local-map) KEY BINDING)
|
||
|
||
*Note (elisp)Key Binding Commands::.
|
||
|
||
-- Function: keymap-global-unset key &optional remove
|
||
This function removes the binding of KEY from the current global
|
||
map.
|
||
|
||
One use of this function is in preparation for defining a longer
|
||
key that uses KEY as a prefix—which would not be allowed if KEY has
|
||
a non-prefix binding. For example:
|
||
|
||
(keymap-global-unset "C-l")
|
||
⇒ nil
|
||
(keymap-global-set "C-l C-l" 'redraw-display)
|
||
⇒ nil
|
||
|
||
*Note (elisp)Key Binding Commands::.
|
||
|
||
-- Function: keymap-local-unset key &optional remove
|
||
This function removes the binding of KEY from the current local
|
||
map.
|
||
|
||
*Note (elisp)Key Binding Commands::.
|
||
|
||
-- Function: keymap-substitute keymap olddef newdef &optional oldmap
|
||
prefix
|
||
Replace OLDDEF with NEWDEF for any keys in KEYMAP now defined as
|
||
OLDDEF. In other words, OLDDEF is replaced with NEWDEF wherever it
|
||
appears. Alternatively, if optional fourth argument OLDMAP is
|
||
specified, we redefine in KEYMAP as NEWDEF those keys that are
|
||
defined as OLDDEF in OLDMAP.
|
||
|
||
-- Function: keymap-lookup keymap key &optional accept-default no-remap
|
||
position
|
||
This function returns the definition of KEY in KEYMAP. All the
|
||
other functions described in this chapter that look up keys use
|
||
‘keymap-lookup’. Here are examples:
|
||
|
||
(keymap-lookup (current-global-map) "C-x C-f")
|
||
⇒ find-file
|
||
(keymap-lookup (current-global-map) "C-x C-f 1 2 3 4 5")
|
||
⇒ 2
|
||
|
||
*Note (elisp)Functions for Key Lookup::.
|
||
|
||
-- Function: keymap-local-lookup keys &optional accept-default
|
||
Like ‘keymap-lookup’, but restricting the search for commands bound
|
||
to KEYS to the current local keymap.
|
||
|
||
-- Function: keymap-global-lookup keys &optional accept-default
|
||
Like ‘keymap-lookup’, but restricting the search for commands bound
|
||
to KEYS to the current global keymap.
|
||
|
||
-- Function: define-keymap &rest definitions
|
||
You can create a keymap with the functions described above, and
|
||
then use ‘keymap-set’ (*note (elisp)Changing Key Bindings::) to
|
||
specify key bindings in that map. When writing modes, however, you
|
||
frequently have to bind a large number of keys at once, and using
|
||
‘keymap-set’ on them all can be tedious and error-prone. Instead
|
||
you can use ‘define-keymap’, which creates a keymap and binds a
|
||
number of keys. Here’s a very basic example:
|
||
|
||
(define-keymap
|
||
"n" #'forward-line
|
||
"f" #'previous-line
|
||
"C-c C-c" #'quit-window)
|
||
|
||
This function creates a new sparse keymap, defines the keystrokes
|
||
in PAIRS, and returns the new keymap.
|
||
|
||
PAIRS is a list of alternating key bindings and key definitions, as
|
||
accepted by ‘keymap-set’. In addition, the key can be the special
|
||
symbol ‘:menu’, in which case the definition should be a menu
|
||
definition as accepted by ‘easy-menu-define’ (*note (elisp)Easy
|
||
Menu::). Here’s a brief example of this usage:
|
||
|
||
(define-keymap :full t
|
||
"g" #'eww-reload
|
||
:menu '("Eww"
|
||
["Exit" quit-window t]
|
||
["Reload" eww-reload t]))
|
||
|
||
A number of keywords can be used before the key/definition pairs to
|
||
change features of the new keymap. If any of the feature keywords
|
||
is missing from the ‘define-keymap’ call, the default value for
|
||
that feature is ‘nil’. Here’s a list of the available feature
|
||
keywords:
|
||
|
||
‘:full’
|
||
If non-‘nil’, create a char-table keymap (as from
|
||
‘make-keymap’) instead of a sparse keymap (as from
|
||
‘make-sparse-keymap’ (*note (elisp)Creating Keymaps::). A
|
||
sparse keymap is the default.
|
||
|
||
‘:parent’
|
||
If non-‘nil’, the value should be a keymap to use as the
|
||
parent (*note (elisp)Inheritance and Keymaps::).
|
||
|
||
‘:keymap’
|
||
If non-‘nil’, the value should be a keymap. Instead of
|
||
creating a new keymap, the specified keymap is modified
|
||
instead.
|
||
|
||
‘:suppress’
|
||
If non-‘nil’, the keymap will be suppressed with
|
||
‘suppress-keymap’ (*note (elisp)Changing Key Bindings::). By
|
||
default, digits and the minus sign are exempt from
|
||
suppressing, but if the value is ‘nodigits’, this suppresses
|
||
digits and minus-sign like it does with other characters.
|
||
|
||
‘:name’
|
||
If non-‘nil’, the value should be a string to use as the menu
|
||
for the keymap if you use it as a menu with ‘x-popup-menu’
|
||
(*note (elisp)Pop-Up Menus::).
|
||
|
||
‘:prefix’
|
||
If non-‘nil’, the value should be a symbol to be used as a
|
||
prefix command (*note (elisp)Prefix Keys::). If this is the
|
||
case, this symbol is returned by ‘define-keymap’ instead of
|
||
the map itself.
|
||
|
||
-- Function: defvar-keymap (variable-name &rest defs)
|
||
By far, the most common thing to do with a keymap is to bind it to
|
||
a variable. This is what virtually all modes do—a mode called
|
||
‘foo’ almost always has a variable called ‘foo-mode-map’.
|
||
|
||
This macro defines NAME as a variable, passes OPTIONS and PAIRS to
|
||
‘define-keymap’, and uses the result as the default value for the
|
||
variable.
|
||
|
||
OPTIONS is like the keywords in ‘define-keymap’, but there’s an
|
||
additional ‘:doc’ keyword that provides the doc string for the
|
||
defined variable.
|
||
|
||
Here’s an example:
|
||
|
||
(defvar-keymap eww-textarea-map
|
||
:parent text-mode-map
|
||
"RET" #'forward-line
|
||
"TAB" #'shr-next-link)
|
||
|
||
-- Macro: while-let spec then-forms...
|
||
Like ‘when-let’, but repeat until a binding in SPEC is ‘nil’. The
|
||
return value is always ‘nil’.
|
||
|
||
This is comparable to ‘and-let*’.
|
||
|
||
-- Macro: ert-with-temp-file name &rest body
|
||
Bind NAME to the name of a new temporary file and evaluate BODY.
|
||
Delete the temporary file after BODY exits normally or non-locally.
|
||
NAME will be bound to the file name of the temporary file. See the
|
||
docstring for supported keyword arguments.
|
||
|
||
-- Macro: ert-with-temp-directory name &rest body
|
||
Bind NAME to the name of a new temporary directory and evaluate
|
||
BODY. Delete the temporary directory after BODY exits normally or
|
||
non-locally.
|
||
|
||
NAME is bound to the directory name, not the directory file name.
|
||
(In other words, it will end with the directory delimiter; on
|
||
Unix-like systems, it will end with "/".)
|
||
|
||
The same keyword arguments are supported as in ‘ert-with-temp-file’
|
||
(which see), except for ‘:text’.
|
||
|
||
-- Function: cl-constantly value
|
||
Return a function that takes any number of arguments, but returns
|
||
VALUE.
|
||
|
||
-- Macro: cl-with-gensyms names... body
|
||
This macro expands to code that executes BODY with each of the
|
||
variables in NAMES bound to a fresh uninterned symbol, or “gensym”,
|
||
in Common Lisp parlance. For macros requiring more than one
|
||
gensym, use of ‘cl-with-gensyms’ shortens the code and renders
|
||
one’s intentions clearer. Compare:
|
||
|
||
(defmacro my-macro (foo)
|
||
(let ((bar (gensym "bar"))
|
||
(baz (gensym "baz"))
|
||
(quux (gensym "quux")))
|
||
`(let ((,bar (+ ...)))
|
||
...)))
|
||
|
||
(defmacro my-macro (foo)
|
||
(cl-with-gensyms (bar baz quux)
|
||
`(let ((,bar (+ ...)))
|
||
...)))
|
||
|
||
-- Macro: cl-once-only ((variable form)...) body
|
||
This macro is primarily to help the macro programmer ensure that
|
||
forms supplied by the user of the macro are evaluated just once by
|
||
its expansion even though the result of evaluating the form is to
|
||
occur more than once. Less often, this macro is used to ensure
|
||
that forms supplied by the macro programmer are evaluated just
|
||
once.
|
||
|
||
Each VARIABLE may be used to refer to the result of evaluating FORM
|
||
in BODY. ‘cl-once-only’ binds each VARIABLE to a fresh uninterned
|
||
symbol during the evaluation of BODY. Then, ‘cl-once-only’ wraps
|
||
the final expansion in code to evaluate each FORM and bind the
|
||
result to the corresponding uninterned symbol. Thus, when the
|
||
macro writer substitutes the value for VARIABLE into the expansion
|
||
they are effectively referring to the result of evaluating FORM,
|
||
rather than FORM itself. Another way to put this is that each
|
||
VARIABLE is bound to an expression for the (singular) result of
|
||
evaluating FORM.
|
||
|
||
The most common case is where VARIABLE is one of the arguments to
|
||
the macro being written, so ‘(variable variable)’ may be
|
||
abbreviated to just ‘variable’.
|
||
|
||
For example, consider this macro:
|
||
|
||
(defmacro my-list (x y &rest forms)
|
||
(let ((x-result (gensym))
|
||
(y-result (gensym)))
|
||
`(let ((,x-result ,x)
|
||
(,y-result ,y))
|
||
(list ,x-result ,y-result ,x-result ,y-result
|
||
(progn ,@forms))))
|
||
|
||
In a call like ‘(my-list (pop foo) ...)’ the intermediate binding
|
||
to ‘x-result’ ensures that the ‘pop’ is not done twice. But as a
|
||
result the code is rather complex: the reader must keep track of
|
||
how ‘x-result’ really just means the first parameter of the call to
|
||
the macro, and the required use of multiple gensyms to avoid
|
||
variable capture by ‘(progn ,@forms)’ obscures things further.
|
||
‘cl-once-only’ takes care of these details:
|
||
|
||
(defmacro my-list (x y &rest forms)
|
||
(cl-once-only (x y)
|
||
`(list ,x ,y ,x ,y
|
||
(progn ,@forms))))
|
||
|
||
2.5.2 Extended Definitions
|
||
--------------------------
|
||
|
||
These functions must be called explicitly via ‘compat-call’, since their
|
||
calling convention or behavior was extended in Emacs 29.1:
|
||
|
||
-- Function: compat-call set-transient-map keymap &optional keep-pred
|
||
on-exit message timeout
|
||
This function adds KEYMAP as a “transient” keymap, which takes
|
||
precedence over other keymaps for one (or more) subsequent keys.
|
||
|
||
Normally, KEYMAP is used just once, to look up the very next key.
|
||
If the optional argument KEEP-PRED is ‘t’, the map stays active as
|
||
long as the user types keys defined in KEYMAP; when the user types
|
||
a key that is not in KEYMAP, the transient keymap is deactivated
|
||
and normal key lookup continues for that key.
|
||
|
||
The KEEP-PRED argument can also be a function. In that case, the
|
||
function is called with no arguments, prior to running each
|
||
command, while KEYMAP is active; it should return non-‘nil’ if
|
||
KEYMAP should stay active.
|
||
|
||
The optional argument ON-EXIT, if non-‘nil’, specifies a function
|
||
that is called, with no arguments, after KEYMAP is deactivated.
|
||
|
||
The optional argument MESSAGE specifies the message to display
|
||
after activating the transient map. If MESSAGE is a string, it is
|
||
the format string for the message, and any ‘%k’ specifier in that
|
||
string is replaced with the list of keys from the transient map.
|
||
Any other non-‘nil’ value of MESSAGE stands for the default message
|
||
format ‘Repeat with %k’.
|
||
|
||
If the optional argument TIMEOUT is non-‘nil’, it should be a
|
||
number that specifies how many seconds of idle time to wait before
|
||
deactivating KEYMAP. The value of the variable
|
||
‘set-transient-map-timeout’, if non-‘nil’, overrides the value of
|
||
this argument.
|
||
|
||
This function works by adding and removing KEYMAP from the variable
|
||
‘overriding-terminal-local-map’, which takes precedence over all
|
||
other active keymaps (*note (Searching Keymaps)elisp::).
|
||
|
||
-- Function: compat-call string-lines string &optional omit-nulls
|
||
keep-newlines
|
||
Split STRING into a list of strings on newline boundaries. If the
|
||
optional argument OMIT-NULLS is non-‘nil’, remove empty lines from
|
||
the results. If the optional argument KEEP-NEWLINES is non-‘nil’,
|
||
don’t remove the trailing newlines from the result strings.
|
||
|
||
*Note (elisp)Creating Strings::.
|
||
|
||
-- Function: compat-call define-key
|
||
This function is like ‘keymap-set’ (*note (elisp)Changing Key
|
||
Bindings::, but understands only the legacy key syntaxes.
|
||
|
||
In addition, this function also has a REMOVE argument. If it is
|
||
non-‘nil’, the definition will be removed. This is almost the same
|
||
as setting the definition to ‘nil’, but makes a difference if the
|
||
KEYMAP has a parent, and KEY is shadowing the same binding in the
|
||
parent. With REMOVE, subsequent lookups will return the binding in
|
||
the parent, whereas with a ‘nil’ definition the lookups will return
|
||
‘nil’.
|
||
|
||
*Note (elisp)Low-Level Key Binding::.
|
||
|
||
This compatibility version handles the optional argument REMOVE.
|
||
|
||
-- Function: compat-call plist-get plist prop &optional predicate
|
||
This returns the value of the PROPERTY property stored in the
|
||
property list PLIST. Comparisons are done with PREDICATE, and
|
||
defaults to ‘eq’. It accepts a malformed PLIST argument. If
|
||
PROPERTY is not found in the PLIST, it returns ‘nil’.
|
||
|
||
*Note (elisp)Plist Access::.
|
||
|
||
This compatibility version handles the optional argument PREDICATE.
|
||
This is a generalized variable (*note (elisp)Generalized
|
||
Variables::) that can be used to change a value with ‘setf’.
|
||
|
||
-- Function: compat-call plist-put plist prop val &optional predicate
|
||
This stores VALUE as the value of the PROPERTY property in the
|
||
property list PLIST. Comparisons are done with PREDICATE, and
|
||
defaults to ‘eq’. It may modify PLIST destructively, or it may
|
||
construct a new list structure without altering the old. The
|
||
function returns the modified property list, so you can store that
|
||
back in the place where you got PLIST.
|
||
|
||
*Note (elisp)Plist Access::.
|
||
|
||
This compatibility version handles the optional argument PREDICATE.
|
||
|
||
-- Function: compat-call plist-member plist prop &optional predicate
|
||
This returns non-‘nil’ if PLIST contains the given PROPERTY.
|
||
Comparisons are done with PREDICATE, and defaults to ‘eq’. Unlike
|
||
‘plist-get’, this allows you to distinguish between a missing
|
||
property and a property with the value ‘nil’. The value is
|
||
actually the tail of PLIST whose ‘car’ is PROPERTY.
|
||
|
||
*Note (elisp)Plist Access::.
|
||
|
||
This compatibility version handles the optional argument PREDICATE.
|
||
|
||
2.5.3 Missing Definitions
|
||
-------------------------
|
||
|
||
Compat does not provide support for the following Lisp features
|
||
implemented in 29.1:
|
||
|
||
• The function ‘imagep’.
|
||
• The function ‘image-at-point-p’.
|
||
• The function ‘function-documentation’.
|
||
• The macro ‘with-undo-amalgamate’.
|
||
• The function ‘string-glyph-split’.
|
||
• The function ‘string-limit’.
|
||
• The function ‘string-pixel-width’ and ‘buffer-text-pixel-size’.
|
||
• The function ‘minibuffer-lazy-highlight-setup’.
|
||
• The function ‘pp-emacs-lisp-code’.
|
||
• The functions ‘xdg-state-home’, ‘xdg-current-desktop’ and
|
||
‘xdg-session-type’.
|
||
• The macro ‘setopt’.
|
||
• The ‘oclosure’ library.
|
||
• The ‘textsec’ library.
|
||
• The ‘range’ library.
|
||
• The ‘string-edit’ library.
|
||
• The ‘vtable’ library.
|
||
• The ‘pixel-fill’ library.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Development, Next: Function Index, Prev: Support, Up: Top
|
||
|
||
3 Development
|
||
*************
|
||
|
||
Compat is developed on GitHub.
|
||
|
||
Bug reports, patches and comments are best sent to the issue tracker
|
||
(https://github.com/emacs-compat/compat/issues). These may include
|
||
issues in the compatibility code, missing definitions or performance
|
||
issues. We also provide a development mailing list
|
||
(https://lists.sr.ht/~pkal/compat-devel) (~pkal/compat-devel@lists.sr.ht
|
||
<~pkal/compat-devel@lists.sr.ht>).
|
||
|
||
Please note that as a GNU ELPA package, Compat requires contributors
|
||
to have signed the FSF copyright assignment
|
||
(https://www.gnu.org/software/emacs/manual/html_node/emacs/Copyright-Assignment.html),
|
||
before any non-trivial contribution (roughly 15 lines of code) can be
|
||
applied. It is important that you provide tests when you contribute new
|
||
functionality. Compat has 100% test coverage by the test suite. We use
|
||
continuous integration to check if patches preserve existing
|
||
functionality.
|
||
|
||
|
||
File: doc0jZUSv.info, Node: Function Index, Next: Variable Index, Prev: Development, Up: Top
|
||
|
||
Appendix A Function Index
|
||
*************************
|
||
|
||
|