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资源说明：Speed improvements for Emacs ido-mode-el
ido-speedup-hack.el
===================
Speed optimisations for Emacs IDO mode. It makes ido completion fast
and interactive even with large sets of completions (eg. list of all
commands in M-x, or large Info index files like Elisp or Emacs
manual).
To achieve maximum speed, download following optimisations:
* [ido-mode-el][] original ido.el
* [ido-better-flex][] optional package with better flexible suggestions.
Installation
------------
To get the best performance, install both ido-speed-hack and ido-mode-el
(and optionally ido-better-flex).
First get latest version from GitHub:
```shell
mkdir ~/emacs-hacks
cd ~/emacs-hacks
git clone https://github.com/orfelyus/ido-mode-el.git
git clone https://github.com/orfelyus/ido-speed-hack.git
# and optionally
git clone https://github.com/orfelyus/ido-better-flex.git
```
Then bytecompile all files for better performance:
```shell
emacs --batch --eval '
(progn
(byte-compile-file "ido-mode-el/ido.el" t)
(byte-compile-file "ido-speed-hack/ido-speed-hack.el" t)
(byte-compile-file "ido-better-flex/ido-better-flex.el" t))
'
```
And finally load from your ~/.emacs file:
```emacs
(load "~/emacs-hacks/ido-mode-el/ido.elc")
(load "~/emacs-hacks/ido-better-flex/ido-better-flex.elc")
(load "~/emacs-hacks/ido-speed-hack/ido-speed-hack.elc")
```
Optimisations
-------------
ido-speed-hack increases ido performance in several ways:
* function inlining (defsubst)
* disabling ido-case-fold for some completions (all commands are lowercase anyway)
* prunning collections based on character bitmaps
* caching character bitmaps during completion or for same completions
* caching intermediate completion lists when adding new characters
Last three optimisations works only when regular expressions are disabled.
Character bitmaps
-----------------
List of completions are prefiltered based on character bitmaps
Character bitmap is computed in function ido-string-to-bitmask.
Each character from a .. z (regardless case) is assigned one bit.
Numbers, special characters - and * has also one bit assigned. 30 bits
are enought to store all flags.
Character bitmap of a string is or of each individual string
characters.
Before ido starts to examine completion list, ido-speed-hack
prefilters the list and removes all words which miss some characters
in ido-text. The filter is based on bitmap comparision.
Bitmap caching
--------------
All bitmaps are cached during an execution of completing-read.
For special commands (execute-extended-command, describe-function,
smex etc) this cache is shared between executions.
Result caching
--------------
If previous completion is a prefix of current completion, speed hack
reuses results from previous call so ido does not start from original
(long) list.
License
=======
Copyright (C) 2012 Daniel Skarda
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see [http://www.gnu.org/licenses/].
[ido-mode-el]: https://github.com/orfelyus/ido-mode-el
[ido-better-flex]: https://github.com/orfelyus/ido-better-flex
本源码包内暂不包含可直接显示的源代码文件，请下载源码包。
