Xah Emacs Blog

New Version of ergoemacs-mode and New Home Page

ErgoEmacs has a new version, lots improvements in past month by Matthew L Fidler. Matt also created a new home page for ErgoEmacs keybinding minor mode. This should be the new home page going forward for community. At http://mlf176f2.github.io/ErgoEmacs/

emacs lisp: you can use ido for automatic completion in your own commands. Example use:

(ido-completing-read "your prompt str:" ‹youList› )

Full example: Emacs: Change Brackets () {} [] in Text

How I Write Blogs Using Emacs

A video recording on how i write blogs.

The commands used are:

• xah-open-file-fast 〔☛ Emacs Lisp: Hotkeys to Open File Fast〕
• insert-date-tag 〔☛ Emacs Lisp: Insert Date Time Stamp〕
• xhm-wrap-html-tag (from Emacs: Xah HTML Mode)
• xhm-pre-source-code syntax coloring of source code in HTML.
• xah-browse-url-of-buffer 〔☛ Emacs Lisp: browse-url Function to View URL in a Web Browser〕
• xah-make-atom-entry 〔☛ Emacs Lisp: Updating Atom Webfeed〕
• dired-jump
• xah-shell-commands. See: 〈Emacs, Shell, Abbrev, and ELISP Power to Bear!〉 http://www.youtube.com/watch?v=oKS_iIoQ0A4

The video presentation is pretty bad. I have much to learn, tech and presentation. I was using Google Plus hangout feature with Hangout On Air to record directly to YouTube. Not sure what's a good solution on Linux yet.

also, i need to write code so that whatever command i called is displayed in a pane. So viewers can see it without me going over.

Dear all, a new version of my tutorial is out. I'm making this a special version, for $40. If you support it, i'd be greatful, and i'll add your name to the Xah's Emacs Tutorial: Acknowledgment as sponsor.

Buy Xah Emacs Tutorial

Another way to voice your support is funding a emacs major mode that you might want. Please visit http://pledgie.com/campaigns/19973. Please let me know if you have questions..

Thank you for support.

Functional Programing Meta Language (ML) in Emacs Lisp!

discovered that emacs has a bundled library for functional programing pattern matching! The package file is 〔pcase.el〕. It's part of GNU Emacs 24.3.1.

it's written by Stefan Monnier, a professor of functional programing research, and one of the two current leader of emacs dev.

you can get to the file by calling describe-function then pcase-let, then click on the file name.

Note: ML stands for Meta Language. It was a family of languages. Current popular descendants include OCaml and Microsoft's FSharp. 〔☛ Xah's OCaml Tutorial〕 Among functional programing languages, OCaml is one of those that's heavily used in the industry (⁖ Mldonkey, Unison 〔☛ Unison Tutorial〕), especially in math formal proof systems ⁖ Coq. And it's famously used in JaneStreet. 〔☛ OCaml Use in Industry: Janestreet Talk by Yaron Minsky 📺〕

Proof systems written in OCaml includes: Coq, HOL Light. 〔☛ State of Theorem Proving Systems 2008〕

Also, the designer of ML is Robin Milner (1934 〜 2010), he died in recent years.

Emacs: CSS: Convert Hex RGB Color to HSL Format

more improved. Emacs: Xah CSS Mode. You can now convert RGB hex color under cursor to HSL format (⁖ #aabbcc ⇒ hsl(210,25%,73%)). Call xcm-hex-color-to-hsl.

why should you convert? because, #rrggbb is one of the hack from history. HSL model isn't perfect, but is much more intuitive. You can change the hue, saturation, and lightness. For some explanation of HSL model and color samples, see: CSS3 HSL (Hue, Saturation, Lightness) Color Samples.

Emacs: new major modes for HTML, CSS, PHP, ELISP, and Lean Emacs LISP Manual

Vote which one you want me to work on. Tell your friends please. http://pledgie.com/campaigns/19973

Emacswiki New Site Design

Looks like emacswiki had a new site design. ⁖ http://www.emacswiki.org/emacs/DiredPlus

the new seems to be a downgrade for me.

now it's black on gray. Parts are gray on gray. Less readable than before. 〔☛ Web Design: Say No to Grey Text on White Background〕

The older logo is much better. It was a real logo, with elements of art. The new, is just plain letters. 〔☛ Purpose of Logo and Principle of Logo Design〕

worst of all, the new site requires JavaScript. Without, you lose some rather significant CSS for readability. This is quite odd.

PS you can go back to the old.

• http://www.emacswiki.org/emacs/2013-04-24?bootstrap=0 old
• http://www.emacswiki.org/emacs/2013-04-24?bootstrap=1 new

but then, that means you must have cookies on.

detail: Keyboard Master: One Thousand Function Keys

ErgoEmacs Keybinding Movement Feature

Matt has done a lot to ErgoEmacs keybinding. I haven't kept up with the features, but i'll blog as i learn. Here's one.

When you use any of the cursor movement keys, you can keep pressing movement key without holding down the Alt. For example, on QWERTY layout, press 【Alt+j j】, it'll move cursor to the left twice. You can turn this off by putting this in your init:

;; turn off ErgoEmacs repeat move without holding Alt feature
(setq ergoemacs-repeat-movement-commands 'nil)

;; set ErgoEmacs repeat movement. Example, on QWERTY, once you press any of 【Alt+i】 or 【Alt+j】 or 【Alt+k】 or 【Alt+l】, then any i j k l key will move cursor, no need to hold Alt anymore. Type any other key automatically exit.
(setq ergoemacs-repeat-movement-commands 'all)

;; set ErgoEmacs repeat move without holding Alt, but one key afterward. Example, on QWERTY, 【Alt+j j】 will move left twice
(setq ergoemacs-repeat-movement-commands 'single)

You can read more about features, settings, on his repo at https://github.com/mlf176f2/ErgoEmacs/tree/master/ergoemacs/ergoemacs-keybindings

emacs lisp is so primitive. You have sort, but it can't sort vector, only list.

also, you can't have literals for hash.

and really lots primitive issues. Any of Perl, Python, Ruby, JavaScript, PHP, beats emacs lisp easily.

the only hope for this to improve is waiting for Guile Scheme Lisp to takeover Elisp. The talk has been on for perhaps a decade now. Last hopeful news i heard is about 2 years ago.

zippy the pinhead

this one is old-school fun.

download this file http://www.vim.org/scripts/script.php?script_id=2411

rename the file and put this in your init:

(setq yow-file "~/.emacs.d/zippy_pinhead_quotes.txt" )

now, open that file, trim out the header and tail. So, the first line should be “Zippy the pinhead data base.” and last line should be the line about “synapses”.

Now, in emacs, call yow, and a zippism will show. To insert, call universal-argument 【Ctrl+u】 first.

(via George Jones)

some digging… the zippy quote were deleted out of copyright concerns, in emacs 22. http://lists.gnu.org/archive/html/emacs-devel/2006-06/msg00290.html

if you don't know, it's a old (1970s) comics. Zippy the Pinhead. See also: Art of Robert Crumb.

Emacs 24.3 Elisp Macro Speedup

emacs 24.3 made elisp code much faster. Quote:

** Emacs tries to macroexpand interpreted (non-compiled) files during load.

This can significantly speed up execution of non-byte-compiled code, but can also bump into previously unnoticed cyclic dependencies. These are generally harmless: they will simply cause the macro calls to be left for later expansion (as before), but will result in a warning (“Eager macro-expansion skipped due to cycle”) describing the cycle. You may wish to restructure your code so this does not happen.

Dmitry Gutov wrote a nice article that shows the speed increase: 〔Emacs 24.3's Killer Feature: Eager Macro-Expansion 2013-04-07 By Dmitry Gutov. @ dgutov.github.io…〕

It's a bit deep. If you code elisp, you should read it. If you don't code elisp, here's the gist:

• Before emacs 23.3, byte-compiled file is about 6 or 10 times faster for loading and also execution
• After emacs 23.3, byte-compiled seems just twice as fast.

via Andrew Hyatt

new version of ErgoEmacs Keybinding is out again. I'm happy to report that the current maintainer Matthew L Fidler has adopted a idea i suggested. Now, “all” of chorded keys has a non-chorded replacement! You can press them by pressing ▤ Menu key first. Here's the current keys:

;; QWERTY used to indicate key position

("<menu> g" keyboard-quit "Quit")
("<menu> j" ergoemacs-ctl-c "Ctl-c")
("<menu> u" ergoemacs-ctl-c-unchorded "Ctl-c*")
("<menu> f" ergoemacs-ctl-x "Ctl-x")

("<menu> h" ergoemacs-ctl-h "Ctl-h")
("<menu> y" ergoemacs-ctl-h-unchorded "Ctl-h*")
("<menu> m" ergoemacs-ctl-c-ctl-c "C-c C-c")
("<menu> SPC" set-mark-command "Set Mark")

The keys are position based, and QWERTY layout is used to indicate their position. That means, doesn't matter whether you are using Dvorak, Colemak, Workman, Bépo, …, you can just look at the labels on your keyboard for the right key. The keys may not be final. But Matt is the maintainer now, so, you'd have to ask him, for suggestions or code push. Also, i haven't been keeping up my documentation of it. I hope to fix it down the road. Another new layout support is Persian standard layout, contributed by Shahin Azad. (it also supports Workman layout. and quite a few others now. You can see all layout supported in the menu 〖ErgoEmacs〗)

Matt also created a emacswiki page at http://www.emacswiki.org/emacs/ErgoemacsKeybindings, so you can post there, ask for help, or help make it better. (Matt says that don't use the emacswiki for question, because it's automatically generated from info file.)

for why about the non-chorded keys, you might get a good idea from my notes here: The Roadmap to Completely Replace Emacs's Key System, Part 2

i think this is really great, because for years i've been thinking how to resolve the cua-mode and emacs C-x issue. Now, i think this is the answer. The implementation is simple, and we don't need the complex hack of cua-mode anymore, and the traditional C-x are still there if one wanted, and the whole system is one step more efficient and ergonomic, even beats vi-like modes. (the main issue of vi's modal ways is that you need to constantly switch modes.)

there's a great page-break-lines-mode by Steve Purcell. It displays FORM FEED char (^L) by a horizontal line. The package is on MELPA. Call list-packages to install. 〔☛ A Guide on Emacs 24 Package System〕

After you install, you need to specify which major modes it should activate. Like this:

(setq page-break-lines-modes (quote (emacs-lisp-mode xah-elisp-mode compilation-mode fundamental-mode text-mode org-mode ruby-mode python-mode xah-html-mode html-mode nxml-mode)) )

this package is great because there are few others but interfere with whitespace-mode settings for some reason. 〔☛ How to Use and Setup Emacs's whitespace-mode〕

Emacs 24 added a new feature. Some function's inline doc now has a link to elisp manual. For example, call describe-variable on “font-lock-defaults”. Excerpt:

font-lock-defaults is a variable defined in `font-core.el'.

…

(See also Info node `(elisp)Font Lock Basics'.)

…

see also New Features in Emacs 24 and Emacs Lisp: Inline Docstring Markup.

actually, not sure this is new in emacs 24. I sure hope every function's inline doc links to elisp manual.

anyhow, you could easily find the elisp doc yourself. See Emacs: Finding Functions and Documentation Lookup. For elisp coders, you might define a advice so that describe-function will always have a link at bottom to elisp manual.

Unicode Rhapsody: Symbols to Represent “emacs lisp”

for Unicode freaks. Found symbols to represent emacs lisp ε ℓ. In normal text, it looks like this “εℓ”. Depending on what browser and OS you are using, it may look beautiful or ugly. Alternatively, use scripted “e” ℯ. ⁖ ℯℓ. But that's got too much affinity with Spanish.

the best way to setup to type them is emacs abbrev system. 〔☛ Using Emacs Abbrev Mode for Abbreviation〕 So, when you type “el”, it automatically becomes “εℓ”. (you can see my current abbrevs at https://github.com/xahlee/xah_emacs_init (it changes about every week.))

likewise, “ε” can represent “emacs” in a pinch, if you want your writing to become cryptic and symbolic logic like, like i do. 😎

though, i can't help but feel something is missing. the scripted “el” is kinda boring. Maybe we need to add a gnu head or something? Though, there's no gnu but ox and water buffalo and ram and goat. 〔☛ Unicode Animal ＆ Insect Icons 🐭 🐮 🐍 🐵 🐞〕

elisp home page got a facelift. Xah Emacs Lisp Tutorial

the design is flow based. Am not fond of fixed-layout. 〔☛ Web Design: Fixed-Layout vs Flowed-Layout〕 If you are learning CSS, checkout CSS Tutorial.

in emacs 24.3, now execute-extended-command is now written in elisp, not C code. You can see the lisp code by calling describe-function. The emacs 24.3 release notes didn't mention this. This change is made by Aaron S Hawley. Thanks Aaron.

• Extending M-x in Emacs 2010-04-27 By Aaron S Hawley. @ aaronhawley.livejournal.com…
• Coding Emacs's M-x in Lisp 2009-09-08 By Aaron S Hawley. @ aaronhawley.livejournal.com…

One great new feature of emacs 24.3:

when you isearch a phrase (⁖ “some thing”) and if the 2 words happens to be hard-wrapped into 2 lines, it'll still find it. In other words, emacs added a feature in isearch such that space can stand for a sequence of whitespaces.

This problem has been bugging me before, and i deeply blame it to the damages unix has done to computing. 〔☛ Programing: the Harm of Hard-wrapping Lines〕 But at least now emacs works-around it.

you can read more about this feature by calling view-emacs-news then search for “isearch”.

Mickey of “Mastering Emacs” wrote a easy-to-understand doc of what's new in emacs 24.3. Check it out. 〔WHAT'S NEW IN EMACS 24.3 2013-03-11 By Mickey Petersen. @ www.masteringemacs.org…〕

emacs 24.3 is out. Download at:

• http://ftp.gnu.org/gnu/emacs/emacs-24.3.tar.xz
• http://ftp.gnu.org/gnu/emacs/emacs-24.3.tar.gz

release notes: http://www.gnu.org/software/emacs/NEWS.24.3

if you don't know how to compile on linux, see Building Emacs on Linux — a Guide

on the keyboard layout front, there's a new layout, the qwpr. See qwpr Keyboard Layout

also, the Workman layout has vastly improved home page, plus now a forum. http://www.workmanlayout.com/

if you are not familiar with all these, see: Keyboard Layouts Fight! Dvorak, Maltron, Colemak, NEO, Bépo, Turkish-F, … (updated with images)

emacs global-set-key macro bug.

The following doesn't work.

(global-set-key (kbd "<menu> u SPC") " ") ; insert non-breaking space

but this works:

(global-set-key (kbd "<menu> u SPC") (lambda () (interactive) (insert " "))) ; insert non-breaking space

GNU Emacs 24.2.1 (i686-pc-linux-gnu, GTK+ Version 2.24.10) of 2013-02-04 on xah-p6813w ErgoEmacs distribution 2.0.0

Emacs: Personal Keybinding, Habit, Muscle Memory, Incompatible Key Sets

when you use your personal key for about 2 months, it becomes muscle memory. Just as people who work among {Windows, Mac, Linux}, or switch between {emacs/bash, browser, photoshop}.

you'd unconsciously learn to adopt the different systems. Though, sometimes some error key press still happen. e.g. on the Mac, emacs copy 【Alt+w】 is prone to close a window — very painful. So, when i used to use default emacs keys, i developed a habit to copy by 【Esc w】.

ideally, all systems should use the same key system, but that's ideal. haha.

sometimes i read people who reviewed ErgoEmacs keybinding and liked it, but is reserved about using it, because it's another set to learn, creating clash with bash. But the fact is, one already is exposed to so many different systems, one just adopt. (btw, current version of ErgoEmacs can generate keysets for bash or AutoHotkey.)

even web browser, doesn't agree on keys, within the same OS. e.g the keys to switch tabs is different on different browser, and few others. Same browser on diff OS also disagree on keys. ⁖ in Chrome, go back is ⌫ Backspace on Windows, but 【Alt+←】 in Linux.

then, even KDE and Gnome don't agree on many keys. What can you do?

emacs packages update: xmsi-mode, ergoemacs-mode

lots more update: Emacs Unicode Math Symbols Input Mode (xmsi-mode). You can get it either by sending me $3 paypal (to xah@xahlee.org) or on ErgoEmacs repository.

also, there's more updates and fixes and features on the ErgoEmacs Keybinding minor mode, by Matthew L Fidler. Get it on MELPA.

hot keyboard news! Logitech now also makes mechanical keyboard. amazon

This is the best straight form mechanical keyboard for programers. See the review for my reasons why.

emacs dired tip: hiding some files

learned a new command. In dired, call dired-do-kill-lines 【k】 to hide marked files. Amazing. Using dired for over a decade and didn't know this command. This is useful when you call find-dired to show all subdirs when you want to do dired-do-query-replace-regexp, but some files you don't want to work on.

new to emacs? onto

• Emacs: File Management, dired Tutorial
• Emacs: Rename Files Interactively by Pattern (regex; wdired)
• Emacs Advanced dired Tips (File Management)
• Emacs: Interactively Find/Replace String Patterns on Multiple Files

Ducky keyboard and KeyBoardCheer keyboard!

discovered that the Ducky keyboard from Taiwan makes real quality keyboards. Check out their website. I don't think you can easily buy it in USA though. But you might be able to buy from the company's site via oversea shipping. (KBC is also quality.)

this gonna be a keyboard week. Lots updates, all about keyboards.

i'll also have lots to say about my new-found-love the Truly Ergonomic Computer Keyboard (TECP). I'll be telling you my experience in adopting the new physical layout.

there are lots new keyboards out there too, including from hushhush and hushhush, won't tell till i write it out.

also, exclusive news, that i'll be writing the firmware for TECP, and tell you how you can help, or sources, etc. For now, just run and buy TECP first. ☺

if you just subscribed to my emacs blog, there's lots existing articles. Do browse around for many tips. After blogging about emacs for 5 years, most generic tips are covered. A good tip is to browse one article a day.

there are still lots of elisp areas i haven't covered and need to learn myself. ⁖ font system, text overlay, window/frame/buffer manipulation, deep understanding of keymap system, process manipulation, networking, minor mode, lisp macros, comprehensive coverage of emacs's completion system, …, i'll gradually do so in the future. So far, the one elisp area i think i pretty much covered is writing interactive or batch text processing commands/scripts. This is probably the most useful.

also, i am starting to do ask emacs Tuesday again. I found that usually i won't be able to answer questions satisfactorily, because the questions are diverse, and usually not about using emacs or elisp, but rather about best modes for xyz or how to make xyz mode do abc. In anycase, i think it's still good to have ask/answer sessions. So, on every Tuesday, you can ask me on any social network, and i'll try my best to answer.

also, again, if you haven't gotten my tutorial, do buy it, as it'll help me really churn out the deeper elisp parts, and create more useful packages (they are all in ErgoEmacs project repo). Only $5 bucks.

Programing Challenge: Replace String Pairs

should be fun. This problem started in elisp for me few years ago. Over the years, tried several elisp approaches… but overall i was stung twice. Few weeks ago, found a bug in my code. Rewrote it with a new algorithm thinking it's much better, but bang, another bug. That is, incorrect behavior.

Now i think i have a good solution, but still has certain limitations. So, am posting this as a fun coding problem, pulling on the talent pool.

am posting this as a general programing problem, not specific to emacs lisp. I do have a elisp solution, but can be easily translated to any other lang.

another keyboard post.

I don't think this is for emacs users, but a fun funky keyboard, with mechanical keys (Cherry MX Black). Levetron Mech gaming keyboard

it uses Cherry MX Black, which is linear but require more force to press. I've tried Cherry MX Black, didn't like it at all.

there's a interesting bit about gaming keyboards. For gaming, many don't like any “click” in key press, because imagine pressing the fire button. You need to press it fast repeatedly, so clicky may not be good.

so, ALMOST ALL gaming keyboards, mechanical switch or not, are designed with linear feel.

in particular, all of Logitech's gaming keyboards (which do not use mechanical switch)

i've tried Logitech keyboard, don't like the key feel at all.

another interesting bit about gaming keyboard is that they are actually the vanguard of keyboard tech. 6 to 20 extra function keys, robust and easy-to-use software for on-the-fly key recording, onboard memory (no need to diddle with AutoHotkey or whatnot xmodmap, wmctrl, xdotool), backlighting, built-in display, all from gaming keyboards.

also, many gaming keyboards do have mechanical keys. I think most uses the Cherry MX Black, but some uses Blue (which is most clicky), or Brown (which is kinda standard for typing). 〔☛ Guide to Computer Keyboard Key Switch Mechanisms〕

Emacs Power Challenge!

another Emacs Power Challenge from jcs. These “emacs golf” problems, seemingly trivial and irrelevant in real world, but is often the most fun way to horn your skills and learn new tricks, which will then burn into your muscle memory and increase your emacs power. Check it out.

〔EmacsGolf Challenge 2 2013-02-19 By Jon Snader. @ irreal.org…〕

for Linux users.

;; after copy Ctrl+c in X11 apps, you can paste by `yank' in emacs
(setq x-select-enable-clipboard t)

;; after mouse selection in X11, you can paste by `yank' in emacs
(setq x-select-enable-primary t)

Is it true that keyboards before PC have Control key right besides the A key?

when doing git push to github in shell inside emacs, it prints the password you typed.

Username for 'https://github.com': xahlee
Password for 'https://xahlee@github.com': 123456

not sure who to blame here.

normally, typed password isn't shown in the clear. But am not sure how emacs detect that. Anyone knows?

emacs golf at Irreal

jcs over at Irreal is thinking of starting a blog or website dedicated to “emacs golf”. I submitted a problem and Jon wrote about it.

See: 〔A First Emacs Challenge 2013-02-09 By Jon Snader. @ irreal.org…〕

What approach would you take?

emacs: ido-mode open file tricks

learned a new trick in ido-mode. When calling ido-find-file, you can use ↑ and ↓ to go to prev/next subdir. Here's a summery.

• {↑, ↓} prev/next subdir
• {←, →} prev/next file.
• {//} root dir.
• 【Ctrl+d】 open dir in dired
• 【Ctrl+f】 switch to default find-file interface.
• 【Tab ↹】 explicit completion, display all files in a split pane. (this is especially useful when ido complains there are too many files.)

not sure what's ido-mode? See:

• Emacs: iswitch vs ido mode
• Emacs: Name Completion Features ＆ Packages
• Tips on Long Term Emacs Productivity

Emacs on Linux vs Windows

if you work between Microsoft Windows and Linux, this might be interesting to you. Linux: Speed Comparison: Linux Perl vs Cygwin Perl vs Strawberry Perl vs ext4 vs NTFS. (The Price You Pay for Layers and Emulations)

emacs on Microsoft Windows is much inferior when compared to Linux version. Here's quick list.

• FTP doesn't work.
• Emacs won't display images.
• File name with Unicode characters (⁖ Chinese) display as gibberish in dired.
• grep, rgrep, and many others won't work.
• If you have installed Cygwin, it's very painful to get path and environment variable correct.
• even if you have Cygwin set up well, grep or cygwin python/perl etc others don't work well work with Unicode strings (or, extremely complex to setup). e.g git commit Unicode ♥, the heart Unicode char in the message will not be commited correctly.
• Calling unix rsync won't work in shell inside emacs. Same for git push.
• many unix commands won't work in shell inside emacs, that otherwise works perfectly in Linux.
• It is perhaps 5 times slower for anything going thru Cygwin.

We try to fixed many of these in ErgoEmacs, but still, many just can't be fixed.