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595 lines
24 KiB
EmacsLisp
595 lines
24 KiB
EmacsLisp
;;; skeleton.el --- Lisp language extension for writing statement skeletons -*- lexical-binding: t; -*-
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;; Copyright (C) 1993-1996, 2001-2024 Free Software Foundation, Inc.
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;; Author: Daniel Pfeiffer <occitan@esperanto.org>
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;; Maintainer: emacs-devel@gnu.org
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;; Keywords: extensions, abbrev, languages, tools
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
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;;; Commentary:
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;; A very concise language extension for writing structured statement
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;; skeleton insertion commands for programming language modes. This
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;; originated in shell-script mode and was applied to ada-mode's
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;; commands which shrunk to one third. And these commands are now
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;; user configurable.
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;;; Code:
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(eval-when-compile (require 'cl-lib))
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;; page 1: statement skeleton language definition & interpreter
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;; page 2: paired insertion
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;; page 3: mirror-mode, an example for setting up paired insertion
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(define-obsolete-variable-alias 'skeleton-transformation
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'skeleton-transformation-function "29.1")
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(defvar skeleton-transformation-function 'identity
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"If non-nil, function applied to literal strings before they are inserted.
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It should take strings and characters and return them transformed, or nil
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which means no transformation.
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Typical examples might be `upcase' or `capitalize'.")
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; this should be a fourth argument to defvar
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(put 'skeleton-transformation-function 'variable-interactive
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"aTransformation function: ")
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(defvar skeleton-autowrap t
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"Controls wrapping behavior of functions created with `define-skeleton'.
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When the region is visible (due to `transient-mark-mode' or marking a region
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with the mouse) and this is non-nil and the function was called without an
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explicit ARG, then the ARG defaults to -1, i.e. wrapping around the visible
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region.")
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(make-obsolete-variable 'skeleton-autowrap nil "24.5")
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(defvar skeleton-end-newline t
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"If non-nil, make sure that the skeleton inserted ends with a newline.")
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(defvar skeleton-end-hook nil
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"Hook called at end of skeleton but before going to point of interest.
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The variables `v1' and `v2' are still set when calling this.")
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(define-obsolete-variable-alias 'skeleton-filter
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'skeleton-filter-function "29.1")
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;;;###autoload
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(defvar skeleton-filter-function 'identity
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"Function for transforming a skeleton proxy's aliases' variable value.")
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(defvar skeleton-untabify nil ; bug#12223
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"When non-nil untabifies when deleting backwards with element -ARG.")
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(defvar skeleton-newline-indent-rigidly nil
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"When non-nil, indent rigidly under current line for element `\\n'.
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Else use mode's `indent-line-function'.")
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(defvar-local skeleton-further-elements ()
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"A buffer-local varlist (see `let') of mode specific skeleton elements.
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These variables are bound while interpreting a skeleton. Their value may
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in turn be any valid skeleton element if they are themselves to be used as
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skeleton elements.")
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(defvar skeleton-subprompt
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(substitute-command-keys
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"RET, \\<minibuffer-local-map>\\[abort-recursive-edit] or \\[help-command]")
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"Replacement for %s in prompts of recursive subskeletons.")
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(defvar skeleton-debug nil
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"If non-nil `define-skeleton' will override previous definition.")
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(defvar skeleton-positions nil
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"List of positions marked with @, after skeleton insertion.
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The list describes the most recent skeleton insertion, and its elements
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are integer buffer positions in the reverse order of the insertion order.")
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;; reduce the number of compiler warnings
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(defvar skeleton-il)
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(defvar skeleton-modified)
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(defvar skeleton-point)
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(defvar skeleton-regions)
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(def-edebug-elem-spec 'skeleton-edebug-spec
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'([&or null stringp (stringp &rest stringp) [[¬ atom] sexp]]
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&rest &or "n" "_" "-" ">" "@" "&" "!" "|" "resume:"
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("quote" def-form) skeleton-edebug-spec def-form))
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;;;###autoload
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(defmacro define-skeleton (command documentation &rest skeleton)
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"Define a user-configurable COMMAND that enters a statement skeleton.
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DOCUMENTATION is that of the command.
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SKELETON is as defined under `skeleton-insert'."
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(declare (doc-string 2) (debug (&define name stringp skeleton-edebug-spec))
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(indent defun))
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(if skeleton-debug
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(set command skeleton))
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`(progn
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;; Tell self-insert-command that this function, if called by an
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;; abbrev, should cause the self-insert to be skipped.
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(put ',command 'no-self-insert t)
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(defun ,command (&optional str arg)
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,(concat documentation
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(if (string-match "\n\\'" documentation)
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"" "\n")
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"\n"
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"This is a skeleton command (see `skeleton-insert').
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Normally the skeleton text is inserted at point, with nothing \"inside\".
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If there is a highlighted region, the skeleton text is wrapped
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around the region text.
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A prefix argument ARG says to wrap the skeleton around the next ARG words.
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A prefix argument of -1 says to wrap around region, even if not highlighted.
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A prefix argument of zero says to wrap around zero words---that is, nothing.
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This is a way of overriding the use of a highlighted region.")
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(interactive "*P\nP")
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(atomic-change-group
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(skeleton-proxy-new ',skeleton str arg)))))
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;;;###autoload
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(defun skeleton-proxy-new (skeleton &optional str arg)
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"Insert SKELETON.
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Prefix ARG allows wrapping around words or regions (see `skeleton-insert').
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If no ARG was given, but the region is visible, ARG defaults to -1 depending
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on `skeleton-autowrap'. An ARG of M-0 will prevent this just for once.
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This command can also be an abbrev expansion (3rd and 4th columns in
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\\[edit-abbrevs] buffer: \"\" command-name).
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Optional second argument STR may also be a string which will be the value
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of `str' whereas the skeleton's interactor is then ignored."
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(skeleton-insert (funcall skeleton-filter-function skeleton)
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;; Pretend C-x a e passed its prefix arg to us
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(if (or arg current-prefix-arg)
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(prefix-numeric-value (or arg
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current-prefix-arg))
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(and skeleton-autowrap
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(use-region-p)
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;; Deactivate the mark, in case one of the
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;; elements of the skeleton is sensitive
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;; to such situations (e.g. it is itself a
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;; skeleton).
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(progn (deactivate-mark)
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-1)))
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(if (stringp str)
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str))
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;; Return non-nil to tell expand-abbrev that expansion has happened.
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;; Otherwise the no-self-insert is ignored.
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t)
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;;;###autoload
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(defun skeleton-insert (skeleton &optional regions str)
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"Insert the complex statement skeleton SKELETON describes very concisely.
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With optional second argument REGIONS, wrap first interesting point
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\(`_') in skeleton around next REGIONS words, if REGIONS is positive.
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If REGIONS is negative, wrap REGIONS preceding interregions into first
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REGIONS interesting positions (successive `_'s) in skeleton.
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An interregion is the stretch of text between two contiguous marked
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points. If you marked A B C [] (where [] is the cursor) in
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alphabetical order, the 3 interregions are simply the last 3 regions.
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But if you marked B A [] C, the interregions are B-A, A-[], []-C.
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The optional third argument STR, if specified, is the value for the
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variable `str' within the skeleton. When this is non-nil, the
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interactor gets ignored, and this should be a valid skeleton element.
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When done with skeleton, but before going back to `_'-point, add
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a newline (unless `skeleton-end-newline' is nil) and run the hook
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`skeleton-end-hook'.
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SKELETON is made up as (INTERACTOR ELEMENT ...). INTERACTOR may be nil if
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not needed, a prompt-string or an expression for complex read functions.
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If ELEMENT is a string or a character it gets inserted (see also
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`skeleton-transformation-function'). Other possibilities are:
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\\n go to next line and indent according to mode, unless
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this is the first/last element of a skeleton and point
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is at bol/eol
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_ interesting point, interregion here
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- interesting point, no interregion interaction, overrides
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interesting point set by _
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> indent line (or interregion if > _) according to major mode
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@ add position to `skeleton-positions'
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& do next ELEMENT if previous moved point
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| do next ELEMENT if previous didn't move point
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-NUM delete NUM preceding characters (see `skeleton-untabify')
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resume: skipped, continue here if quit is signaled
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nil skipped
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After termination, point will be positioned at the last occurrence of -
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or at the first occurrence of _ or at the end of the inserted text.
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Note that \\n as the last element of the skeleton only inserts a
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newline if not at eol. If you want to unconditionally insert a newline
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at the end of the skeleton, use \"\\n\" instead. Likewise with \\n
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as the first element when at bol.
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Further elements can be defined via `skeleton-further-elements'.
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ELEMENT may itself be a SKELETON with an INTERACTOR. The user is prompted
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repeatedly for different inputs. The SKELETON is processed as often as
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the user enters a non-empty string. \\[keyboard-quit] terminates skeleton insertion, but
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continues after `resume:' and positions at `_' if any. If INTERACTOR in
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such a subskeleton is a prompt-string which contains a \".. %s ..\" it is
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formatted with `skeleton-subprompt'. Such an INTERACTOR may also be a list
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of strings with the subskeleton being repeated once for each string.
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Quoted Lisp expressions are evaluated for their side-effects.
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Other Lisp expressions are evaluated and the value treated as above.
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Note that expressions may not return t since this implies an
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endless loop. Modes can define other symbols by locally setting them
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to any valid skeleton element. The following local variables are
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available:
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str first time: read a string according to INTERACTOR
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then: insert previously read string once more
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help help-form during interaction with the user or nil
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input initial input (string or cons with index) while reading str
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v1, v2 local variables for memorizing anything you want"
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(let ((skeleton-regions regions))
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(and skeleton-regions
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(setq skeleton-regions
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(if (> skeleton-regions 0)
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(list (copy-marker (point) t)
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(save-excursion (forward-word-strictly
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skeleton-regions)
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(point-marker)))
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(setq skeleton-regions (- skeleton-regions))
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;; copy skeleton-regions - 1 elements from `mark-ring'
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(let ((l1 (cons (mark-marker) mark-ring))
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(l2 (list (copy-marker (point) t))))
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(while (and l1 (> skeleton-regions 0))
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(push (copy-marker (pop l1) t) l2)
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(setq skeleton-regions (1- skeleton-regions)))
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(sort l2 '<))))
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(goto-char (car skeleton-regions))
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(setq skeleton-regions (cdr skeleton-regions)))
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(let ((beg (point))
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skeleton-modified skeleton-point) ;; resume:
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(with-suppressed-warnings ((lexical help input v1 v2))
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(dlet (help input v1 v2)
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(setq skeleton-positions nil)
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(unwind-protect
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(cl-progv
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(mapcar #'car skeleton-further-elements)
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(mapcar (lambda (x) (eval (cadr x) t)) skeleton-further-elements)
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(skeleton-internal-list skeleton str))
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(or (eolp) (not skeleton-end-newline) (newline-and-indent))
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(run-hooks 'skeleton-end-hook)
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(sit-for 0)
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(or (not (eq (window-buffer) (current-buffer)))
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(pos-visible-in-window-p beg)
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(progn
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(goto-char beg)
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(recenter 0)))
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(if skeleton-point
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(goto-char skeleton-point))))))))
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(defun skeleton-read (prompt &optional initial-input recursive)
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"Function for reading a string from the minibuffer within skeletons.
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PROMPT must be a string or a function that evaluates to a string.
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It may also be a form that evaluates to a string (deprecated).
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It may contain a `%s' which will be replaced by `skeleton-subprompt'.
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If non-nil second arg INITIAL-INPUT or variable `input' is a string or
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cons with index to insert before reading. If third arg RECURSIVE is non-nil
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i.e. we are handling the iterator of a subskeleton, returns empty string if
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user didn't modify input.
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While reading, the value of `minibuffer-help-form' is variable `help' if that
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is non-nil or a default string."
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(with-suppressed-warnings ((lexical help)) (defvar help)) ;FIXME: Prefix!
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(let ((minibuffer-help-form (or (bound-and-true-p help)
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(if recursive "\
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As long as you provide input you will insert another subskeleton.
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If you enter the empty string, the loop inserting subskeletons is
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left, and the current one is removed as far as it has been entered.
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If you quit, the current subskeleton is removed as far as it has been
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entered. No more of the skeleton will be inserted, except maybe for a
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syntactically necessary termination."
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"\
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You are inserting a skeleton. Standard text gets inserted into the buffer
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automatically, and you are prompted to fill in the variable parts.")))
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(eolp (eolp)))
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;; since Emacs doesn't show main window's cursor, do something noticeable
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(or eolp
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;; We used open-line before, but that can do a lot more than we want,
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;; since it runs self-insert-command. E.g. it may remove spaces
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;; before point.
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(save-excursion (insert "\n")))
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(unwind-protect
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(setq prompt (cond ((stringp prompt)
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;; The user may issue commands to move
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;; around (like `C-M-v'). Ensure that we
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;; insert the skeleton at the correct
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;; (initial) point.
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(save-excursion
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(read-string (format prompt skeleton-subprompt)
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(setq initial-input
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(or initial-input
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(symbol-value 'input))))))
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((functionp prompt)
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(funcall prompt))
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(t (eval prompt))))
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(or eolp
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(delete-char 1))))
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(if (and recursive
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(or (null prompt)
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(string= prompt "")
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(equal prompt initial-input)
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(equal prompt (car-safe initial-input))))
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(signal 'quit t)
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prompt))
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(defun skeleton-internal-list (skeleton &optional str recursive)
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(let* ((start (line-beginning-position))
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(column (current-column))
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(line (buffer-substring start (line-end-position)))
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(skeleton-il skeleton)
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opoint)
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(with-suppressed-warnings ((lexical str))
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(dlet ((str (or str
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`(setq str
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(skeleton-read ',(car skeleton-il)
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nil ,recursive))))
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resume:)
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(when (and (eq (cadr skeleton-il) '\n) (not recursive)
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(save-excursion (skip-chars-backward " \t") (bolp)))
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(setq skeleton-il (cons nil (cons '> (cddr skeleton-il)))))
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(while (setq skeleton-modified (eq opoint (point))
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opoint (point)
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skeleton-il (cdr skeleton-il))
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(condition-case quit
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(skeleton-internal-1 (car skeleton-il) nil recursive)
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(quit
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(if (eq (cdr quit) 'recursive)
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(setq recursive 'quit
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skeleton-il (memq 'resume: skeleton-il))
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;; Remove the subskeleton as far as it has been shown
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;; the subskeleton shouldn't have deleted outside current line.
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(end-of-line)
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(delete-region start (point))
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(insert line)
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(move-to-column column)
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(if (cdr quit)
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(setq skeleton-il ()
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recursive nil)
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(signal 'quit 'recursive)))))))))
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;; maybe continue loop or go on to next outer resume: section
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(if (eq recursive 'quit)
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(signal 'quit 'recursive)
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recursive))
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(defun skeleton-internal-1 (element &optional literal recursive)
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(cond
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((or (integerp element) (stringp element))
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(if (and (integerp element) ; -num
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(< element 0))
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(if skeleton-untabify
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(backward-delete-char-untabify (- element))
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(delete-char element))
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(insert (if (not literal)
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(funcall skeleton-transformation-function element)
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element))))
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((or (eq element '\n) ; actually (eq '\n 'n)
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;; The sequence `> \n' is handled specially so as to indent the first
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;; line after inserting the newline (to get the proper indentation).
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(and (eq element '>) (eq (nth 1 skeleton-il) '\n) (pop skeleton-il)))
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(let ((pos (if (eq element '>) (point))))
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(cond
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((and skeleton-regions (eq (nth 1 skeleton-il) '_))
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(or (eolp) (insert "\n"))
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(if pos (save-excursion (goto-char pos) (indent-according-to-mode)))
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(indent-region (line-beginning-position)
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(car skeleton-regions) nil))
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;; \n as last element only inserts \n if not at eol.
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((and (null (cdr skeleton-il)) (not recursive) (eolp))
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(if pos (indent-according-to-mode)))
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(skeleton-newline-indent-rigidly
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(let ((pt (point)))
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(insert "\n")
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(indent-to (save-excursion
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(goto-char pt)
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(if pos (indent-according-to-mode))
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(current-indentation)))))
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(t (if pos (reindent-then-newline-and-indent)
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(insert "\n")
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(indent-according-to-mode))))))
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((eq element '>)
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(if (and skeleton-regions (eq (nth 1 skeleton-il) '_))
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(indent-region (line-beginning-position)
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(car skeleton-regions) nil)
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(indent-according-to-mode)))
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((eq element '_)
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(if skeleton-regions
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(progn
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(goto-char (pop skeleton-regions))
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(and (<= (current-column) (current-indentation))
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(eq (nth 1 skeleton-il) '\n)
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(end-of-line 0)))
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(or skeleton-point
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(setq skeleton-point (point)))))
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((eq element '-)
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(setq skeleton-point (point)))
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((eq element '&)
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(when skeleton-modified (pop skeleton-il)))
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((eq element '|)
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(unless skeleton-modified (pop skeleton-il)))
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((eq element '@)
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(push (point) skeleton-positions))
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((eq 'quote (car-safe element))
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(eval (nth 1 element)))
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((and (consp element)
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(or (stringp (car element)) (listp (car element))))
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;; Don't forget: `symbolp' is also true for nil.
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(if (symbolp (car-safe (car element)))
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(while (and (skeleton-internal-list element nil t)
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;; If the interactor is nil, don't infinite loop.
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(car element)))
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(setq literal (car element))
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(while literal
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(skeleton-internal-list element (car literal))
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(setq literal (cdr literal)))))
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((null element))
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(t (skeleton-internal-1 (eval element) t recursive))))
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;; Maybe belongs into simple.el or elsewhere
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;; ;;;###autoload
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;; (define-skeleton local-variables-section
|
||
;; "Insert a local variables section. Use current comment syntax if any."
|
||
;; (completing-read "Mode: " obarray
|
||
;; (lambda (symbol)
|
||
;; (if (commandp symbol)
|
||
;; (string-match "-mode$" (symbol-name symbol))))
|
||
;; t)
|
||
;; '(save-excursion
|
||
;; (if (re-search-forward page-delimiter nil t)
|
||
;; (error "Not on last page")))
|
||
;; comment-start "Local Variables:" comment-end \n
|
||
;; comment-start "mode: " str
|
||
;; & -5 | '(kill-line 0) & -1 | comment-end \n
|
||
;; ( (completing-read (format "Variable, %s: " skeleton-subprompt)
|
||
;; obarray
|
||
;; (lambda (symbol)
|
||
;; (or (eq symbol 'eval)
|
||
;; (custom-variable-p symbol)))
|
||
;; t)
|
||
;; comment-start str ": "
|
||
;; (read-from-minibuffer "Expression: " nil read-expression-map nil
|
||
;; 'read-expression-history) | _
|
||
;; comment-end \n)
|
||
;; resume:
|
||
;; comment-start "End:" comment-end \n)
|
||
|
||
;; Variables and command for automatically inserting pairs like () or "".
|
||
|
||
(defvar skeleton-pair nil
|
||
"If this is nil pairing is turned off, no matter what else is set.
|
||
Otherwise modes with `skeleton-pair-insert-maybe' on some keys
|
||
will attempt to insert pairs of matching characters.")
|
||
|
||
|
||
(defvar skeleton-pair-on-word nil
|
||
"If this is nil, paired insertion is inhibited before or inside a word.")
|
||
|
||
|
||
(defvar skeleton-pair-filter-function (lambda () nil)
|
||
"Attempt paired insertion if this function returns nil, before inserting.
|
||
This allows for context-sensitive checking whether pairing is appropriate.")
|
||
|
||
|
||
(defvar skeleton-pair-alist ()
|
||
"An override alist of pairing partners matched against `last-command-event'.
|
||
Each alist element, which looks like (ELEMENT ...), is passed to
|
||
`skeleton-insert' with no interactor. Variable `str' does nothing.
|
||
|
||
Elements might be (?\\=` ?\\=` _ \"\\='\\='\"), (?\\( ? _ \" )\") or (?{ \\n > _ \\n ?} >).")
|
||
|
||
(defvar skeleton-pair-default-alist '((?\( _ ?\)) (?\))
|
||
(?\[ _ ?\]) (?\])
|
||
(?{ _ ?}) (?\})
|
||
(?< _ ?>) (?\>)
|
||
(?« _ ?») (?\»)
|
||
(?` _ ?')))
|
||
|
||
;;;###autoload
|
||
(defun skeleton-pair-insert-maybe (arg)
|
||
"Insert the character you type ARG times.
|
||
|
||
With no ARG, if `skeleton-pair' is non-nil, pairing can occur. If the region
|
||
is visible the pair is wrapped around it depending on `skeleton-autowrap'.
|
||
Else, if `skeleton-pair-on-word' is non-nil or we are not before or inside a
|
||
word, and if `skeleton-pair-filter-function' returns nil, pairing is performed.
|
||
Pairing is also prohibited if we are right after a quoting character
|
||
such as backslash.
|
||
|
||
If a match is found in `skeleton-pair-alist', that is inserted, else
|
||
the defaults are used. These are (), [], {}, <> and (grave
|
||
accent, apostrophe) for the paired ones, and the same character
|
||
twice for the others."
|
||
(interactive "*P")
|
||
(if (or arg (not skeleton-pair))
|
||
(self-insert-command (prefix-numeric-value arg))
|
||
(let* ((mark (and skeleton-autowrap
|
||
(or (eq last-command 'mouse-drag-region)
|
||
(and transient-mark-mode mark-active))))
|
||
(char last-command-event)
|
||
(skeleton (or (assq char skeleton-pair-alist)
|
||
(assq char skeleton-pair-default-alist)
|
||
`(,char _ ,char))))
|
||
(if (or (memq (char-syntax (preceding-char)) '(?\\ ?/))
|
||
(and (not mark)
|
||
(or overwrite-mode
|
||
(if (not skeleton-pair-on-word) (looking-at "\\w"))
|
||
(funcall skeleton-pair-filter-function))))
|
||
(self-insert-command (prefix-numeric-value arg))
|
||
;; Newlines not desirable for inserting pairs. See bug#16138.
|
||
(let ((skeleton-end-newline nil))
|
||
(skeleton-insert (cons nil skeleton) (if mark -1)))))))
|
||
|
||
|
||
;; A more serious example can be found in sh-script.el
|
||
;; (defun mirror-mode ()
|
||
;; "This major mode is an amusing little example of paired insertion.
|
||
;;All printable characters do a paired self insert, while the other commands
|
||
;;work normally."
|
||
;; (interactive)
|
||
;; (kill-all-local-variables)
|
||
;; (make-local-variable 'skeleton-pair)
|
||
;; (make-local-variable 'skeleton-pair-on-word)
|
||
;; (make-local-variable 'skeleton-pair-filter-function)
|
||
;; (make-local-variable 'skeleton-pair-alist)
|
||
;; (setq major-mode 'mirror-mode
|
||
;; mode-name "Mirror"
|
||
;; skeleton-pair-on-word t
|
||
;; ;; in the middle column insert one or none if odd window-width
|
||
;; skeleton-pair-filter-function (lambda ()
|
||
;; (if (>= (current-column)
|
||
;; (/ (window-width) 2))
|
||
;; ;; insert both on next line
|
||
;; (next-line 1)
|
||
;; ;; insert one or both?
|
||
;; (= (* 2 (1+ (current-column)))
|
||
;; (window-width))))
|
||
;; ;; mirror these the other way round as well
|
||
;; skeleton-pair-alist '((?) _ ?()
|
||
;; (?] _ ?[)
|
||
;; (?} _ ?{)
|
||
;; (?> _ ?<)
|
||
;; (?/ _ ?\\)
|
||
;; (?\\ _ ?/)
|
||
;; (?` ?` _ "''")
|
||
;; (?' ?' _ "``"))
|
||
;; ;; in this mode we exceptionally ignore the user, else it's no fun
|
||
;; skeleton-pair t)
|
||
;; (let ((map (make-vector 256 'skeleton-pair-insert-maybe))
|
||
;; (i 0))
|
||
;; (use-local-map `(keymap ,map))
|
||
;; (while (< i ? )
|
||
;; (aset map i nil)
|
||
;; (aset map (+ i 128) nil)
|
||
;; (setq i (1+ i))))
|
||
;; (run-mode-hooks 'mirror-mode-hook))
|
||
|
||
(provide 'skeleton)
|
||
|
||
;;; skeleton.el ends here
|