Xah Emacs Blog Archive 2024-06

• 2024-12-31
• Emacs: xah-elisp-util.el 📦
• improved many functions dealing with images

• 2024-12-31
• Emacs: Xah Dired Mode (xah-dired.el) 📦
• removed xah-dired-image-remove-transparency. might add back later.
• removed xah-dired-2drawing
• renamed xah-dired-2jpg to xah-dired-to-jpg
• renamed xah-dired-2png to xah-dired-to-png
• removed xah-dired-imagemagick-path. now just assume magick.
• removed internal xah-do-image, xah-process-image.
• now all image commands call magick by call-process and do not start shell.
• now all image commands call imagemagick version 7 syntax by magick, no “convert”.

• 2024-12-26
• Emacs: Xah Math Input Mode 📦
• minor tweaks

• Emacs: File Manager, dired
• Emacs Init: Dired Config
• Emacs: Dired Sort File by Time, Size 📜
• Emacs: Open Marked Files in Dired 📜
• Xah Emacs Commands

• Emacs: Relation of Cursor Position to Begin/End of Matching Pairs in Source Code

• 2024-12-25
• Emacs: Xah Wolfram Mode 📦
• xah-wolfram-eval-region now more efficient, use call-process instead of starting shell. (not tested on mac or linux. please file bug report if problem)
• xah-wolfram-eval-buffer new. (key tab b)
• removed xah-wolfram-run-script, xah-wolfram-run-script-print-last, xah-wolfram-run-script-print-all

• Emacs: Format HTML Code 📜

• learn the difference between wildcard vs regex (glob pattern vs regular expression)
• Emacs: Wildcards vs Regular Expression

• 2024-12-22
• xah-python-mode.el
• xah-python-format-buffer now faster, call call-process instead of shell. remove support for yapf.

• 2024-12-22
• Emacs: Xah JS Mode (JavaScript) 📦
• xah-js-eval-line now faster using call-process-region instead of shell.
• xah-js-format-buffer now faster using call-process instead of shell.
• xah-js-format-file removed.

• 2024-12-22
• Emacs: Xah PowerShell Mode 📦
• xah-pwsh-format-buffer now faster using call-process-region instead of shell.

• 2024-12-22
• Emacs: Xah Go Mode 📦
• xah-go-format-buffer now faster using call-process instead of shell.

For coders. Press a button in emacs, and automatically format code of entire file. Never waste time doing line based indent. For JavaScript golang. And python PowerShell.

• Emacs: Format JavaScript Code 📜
• Emacs: Format Python Code 📜
• Emacs: Format Golang Code 📜
• Emacs: Format PowerShell Code 📜

lots update.

• Elisp: Association List

• 2024-12-20
• Emacs: Xah Fly Keys 📦
• xah-run-current-file major rewrite. now use start-process and does not make a shell call. also support java file again.

• Emacs: Run Current File 📜

• Elisp: Get Text at Cursor (thing-at-point)
• Elisp: Problems of thing-at-point

• 2024-12-12
• Emacs: Xah JS Mode (JavaScript) 📦
• Rewrite xah-js-eval-region. Now use stdin instead of temp file. Much faster.
• No longer require Emacs: xah-get-thing.el 📦
• Fixed xah-major-leader-key not bound error.

• 2024-12-12
• Emacs: Xah PowerShell Mode 📦
• Rewrite xah-js-eval-region. Now use stdin instead of temp file. Much faster.
• Fixed xah-major-leader-key not bound error.
• key change for xah-pwsh-eval-region
• No longer require Emacs: xah-get-thing.el 📦

• 2024-12-12
• Emacs: Xah Wolfram Mode 📦
• xah-wolfram-eval-region minor change. now temp file is in a subdir xah_emacs in operating system temp dir.

shell call with temp file vs pass to stdin

• massive coding.
• rewrote several emacs lisp commands to eval a region of code of JavaScript python perl Wolfram language.

• xah-js-eval-region
• xah-pwsh-eval-region
• xah-python-eval-region

• normally, you create a temp file.
• and shell call e.g. python tempdir/filename
• but that is lots problems.
• you need to create a subdirectory in the operating system temp dir, gen temp file name.
• then, you have cleanup problem. when to do it, or list dir of maybe thousand files, delete by date. etc.

• but better way, is to pass code to stdin.
• e.g. deno run -
• now it's much faster. because you don't nee to create file and the programing language interpreter dont need to read a file. IO is very slow.
• however, the trick is to know how in emacs lisp, via call-process-region.
• it's slightly more complex than making a shell call.

• by the way you can find on my emacs lisp tutorial.
• Elisp: Start External Process

• Emacs Keys: Key Sequence

• Emacs: URL Percent Encode Decode 📜
• Elisp: URL Percent Decode, Encode

• Emacs: Jump to Previous Position
• Emacs: Replace Invisible Unicode Chars 📜

major update.

• Emacs: Regular Expression Syntax
• Elisp: Unicode Escape Sequence

• Emacs: Toggle Monospace / Proportional Font

massively revamped.

• Elisp: Character Type
• Elisp: Syntax Table
• Elisp: Syntax Class
• Elisp: Show Syntax Table
• Elisp: Show Char's Syntax
• Elisp: Create Syntax Table
• Elisp: Syntax Descriptor
• Elisp: Modify Syntax Table Temporarily
• Elisp: Determine Cursor is Inside String or Comment
• Elisp: Find Matching Bracket Character

• ASCII Characters
• Unicode: Codepoint

• Elisp: Font Lock Mode
• Elisp: Syntax Color Comments

• Why You Need to Understand ASCII Control Characters
• Emacs Lisp Coding Style

• Xah Emacs Blog Archive 2018-10

• Emacs Misc Index

• Emacs Init: Install Package Manually
• Elisp: Load Path
• Elisp: load, load-file, autoload

• Text Processing: Emacs Lisp vs Perl
• Why Nobody Uses Emacs Lisp for Text Processing (2017)

more update

• Emacs Keys: Define Key
• Emacs Keys: Keybinding Functions, Emacs 29 Change
• Emacs 29 (date 2023)
• Emacs: Microsoft Windows: Init File Location

• 🆕 Elisp: Difference Between Association List vs List of Pairs
• Elisp: Association List

• 🆕 Emacs Bug: file-exists-p (2024-11-27)

• Emacs: Microsoft Windows: Run PowerShell

• Elisp: Parse URL 📜

• Emacs: Xah Fly Keys. Key for Org-Mode

• Elisp: Hash Table
• Elisp: Pretty Print Hash Table
• Elisp: Hash Table to List
• Elisp: Sort Hash Table

environment variable complexity

• For coders. Emacs.
• Why Programing is Extremely Complex.

• Took 3 hours to debug, why is
• C:/Python39/
• in my emacs exec-path, even when i removed it from Microsoft Windows environment variable in registry.

• turns out, because i was launching emacs via AutoHotkey, and it was still using the old registry value.
• restart windows solved the problem.

• in the process, also debugged or improved many of my init files.
• when checking a variable, use boundp instead just the symbol.
• eg
• (when (boundp 'icomplete-vertical-mode-minibuffer-map) ...)

• not:
• (when 'icomplete-vertical-mode-minibuffer-map ...)

• Elisp: Get Version, Host Name, User Name, Init Dir
• Emacs Init: Environment Variables
• Elisp: exec-path, External Program Search Paths

• Elisp: provide, require, features

• 🆕 Elisp: Get Operating System Type

• Elisp: Get Version, Host Name, User Name, Init Dir
• Emacs: Show Version

code update.

• Emacs: Quote Lines 📜
• Emacs: Select Text Between Quotes 📜

• Emacs Flaw: Elisp Syntax Table
• Why Nobody Uses Emacs Lisp for Text Processing (2017)

• Elisp: Benchmark, Test Speed
• Elisp: Unit Testing

• massively rewrote the code to get image width and height, so it doesn't need the mega bloated imagemagick.
• Elisp: Get Image Size 📜

• Emacs: xah-elisp-util.el 📦

• added
• length=
• length>
• length<
• take
• ntake

• Elisp: List
• Elisp: List, Get Elements
• Elisp: Modify List

• Emacs Init: Timing Startup Time

• major update
• Elisp: Start External Process

• Emacs Init: Environment Variables
• 🆕 Elisp: exec-path, External Program Search Paths

• Emacs bug, Elisp Get Image Width Height. 2024-11

• Emacs Bugs Index

• 🆕 Emacs: xah-elisp-util.el 📦
• Emacs: xah-get-thing.el 📦
• Emacs: xah-replace-pairs.el 📦

code update

• 🆕 Elisp: Get Image Size 📜
• Emacs: Open Python Doc 📜
• Emacs: Show in Desktop 📜
• Emacs: Open File in External App 📜

code update

• Emacs: URL Percent Encode Decode 📜

major rewrite.

• Elisp: Call Shell Command
• Elisp: Call Shell Command on Region
• Elisp: Start External Process

• Elisp: Get Command Line Arguments
• Elisp: Run Elisp Script in Terminal
• Emacs: MacOS: Start Emacs from Terminal
• Emacs: Microsoft Windows: Start Emacs from Terminal

• Emacs: Format Python Code 📜
• Emacs: Format JavaScript Code 📜
• Emacs: Format Golang Code 📜
• Emacs: Format PowerShell Code 📜

• Emacs: Microsoft Windows Tips

• Emacs Lisp Examples
• Xah Emacs Commands

• Emacs: Sort Lines
• Emacs: Align Text Column

updates

• Elisp: Unit Testing
• Elisp: Join Strings, Codepoints to String

• 2024-11-09
• Emacs: Xah Fly Keys 📦
• xah-close-current-buffer now has a option xah-create-buffer-backup

• Emacs Keys: Change Major Mode Keys

updates

• 🆕 Emacs: Toggle Background Color 📜
• Emacs: New Empty Buffer 📜
• Emacs: Cycle Color Theme, Toggle 📜

• Elisp: Proper List
• Elisp: Symbol Property List
• Elisp: How to Write a Toggle Command

• Xah Emacs Commands

• Emacs: Xah Lookup Web (xah-lookup.el) 📦

misc updates.

• Emacs Init: Mouse Button Syntax
• Emacs: Mouse Wheel Commands
• Emacs: Move Cursor by Text Block 📜

• Emacs: Run Shell

• Xah Talk Show 2024-10-29 Ep594, Emacs Lisp Coding, Command to Search YouTube
• Emacs: Xah Lookup Web (xah-lookup.el) 📦
• Emacs: Command to Lookup Doc or Search Web 📜

• The New Left Review and RICHARD STALLMAN

Replace replace-regexp-in-string by string-replace

emacs lisp. in your code, replace all replace-regexp-in-string by string-replace (new in 2022). if you are not doing regex.

• Elisp: String Functions

• Elisp: HTML. Chinese Char To Reference Link

Stop Using Lisp Cons

• Programing language, regarding lisp cons.
• This is the final say.
• The common lispers, have always been, the most idiotic bunch, in the past 30 years as far as i get to know them.

• Lisp cons, to this day, is the most idiotic concept in programing language history.
• It is lisp cons, that killed lisp. Except, clojure, which ditched cons entirely.
• Nobody the faak do linked list today.
• It is not in all other langs since y2k.
• Only the lisp fanatics, still like chew it like fine wine, thinking, how great it is or was.

• the way to fix the lisp cons, is to ban any list that is not a proper list.
• that should be done since y2k.
• but today, there is more reason to not use lisp list, even proper list, due to parallel computation.

• Guy Steele Says: Don't Iterate, Recurse, and Get rid of lisp cons!

• In your lisp code, go thru it and find all use of cons. Replace it with vector.
• And for list, check if you are using it as stack datatype. If not, replace it with vector.
• You'll have more efficient code.

• Exception is association list. Check if you are using it as ordered dictionary. If so, and length is say less than 20, stays. Else, replace it with real hashtable.
• For property list and symbol property list, they need to stay, because backward compatibility issues.

• Elisp: Cons Cell
• Elisp: Proper List
• Elisp: Vector
• Elisp: Property List
• Elisp: Symbol Property List

• 2024-10-09
• Emacs: Xah Fly Keys 📦
• added xah-page-up and xah-page-down commands.

• Who is lispm on Hackernews

• Emacs Init: Variable Pitch Mode (Proportional Font)

• 2024-10-07
• Emacs: Xah Fly Keys 📦
• major fix on many commands that works on text block. few months ago made a change so that blank lines containing space or tab is not considered blank. the result is not good. now fixed. also, renamed xah-get-pos-of-block to xah-fly-get-pos-block etc.
• xah-run-current-file-map, py3 changed to run python, not python3.
• fixed a bug in xah-select-text-in-quote.

major bug fix.

• Elisp: Get Text Block 📜
• Emacs: Delete Text Block 📜

updates.

• Best Unicode Fonts for Coders

• Emacs Init: Font for Emoji
• Emacs Init: Font for Unicode Symbols
• Emacs Init: Font for Chinese

updates.

• Emacs: Open Python Doc 📜
• Emacs: Jargons (Glossary)
• Emacs: Major Mode
• Elisp: Print Date Time
• Elisp: Parse Date Time

• Elisp: Buffer Functions

• Origin of Line Wrap at 80 Chars (Punched Cards)

• Emacs Magit Mode Problem

• Emacs: Replacing HTML Entities with Unicode Characters

• Emacs: HTML Entities. Ampersand Encoding, Decoding 📜

• Emacs: Convert File Line Ending 📜

• Emacs: Split Window

• 2024-09-27
• Emacs: Xah Fly Keys 📦
• major key reorg. removed most starting with C-x, and other change. see below.
• Removed most keys starting with C-x. Reason is when you do M-x for some rarely used command, the C-x binding shows in minibuffer in precedence over leader key sequence. This makes it harder to know the easier key.
• Removed many C- keys such as C-p for moving cursor right. They were there so that emacs default key users might use them. But those people are not likely to adopt Xah Fly Keys anyway. Beginners simply press arrow keys.
• Added some 10 plus keys for kmacro commands. These are almost never used but good to have keys for the handful advanced emacs users. Each now has a leader key sequence. The exact key is to be changed.

• gnu_emacs_29_keybinding.txt
• Emacs: One Thousand Default Keybinding

(setq word-wrap-by-category t)

• Emacs: Toggle Word Wrap

thanks to jamesni.

• Emacs: Next/Previous User Buffer 📜

• 2024-09-24
• Emacs: Xah Fly Keys 📦
• added arrow keys to xah-previous-user-buffer xah-next-user-buffer xah-previous-emacs-buffer xah-next-emacs-buffer. you can press arrow keys to repeat. see docstring.

also thanks to emiltoacs for improvement.

• 🆕 Elisp: Join Strings, Codepoints to String
• Elisp: Sequence. Join, Convert

• added new function string-replace
• Elisp: String Functions

• Emacs: xah-get-thing.el 📦
• Elisp: Get Text Block 📜

translate-region

subst-char-in-string

;; this is in C
subst-char-in-region

can be used for my asccify command

• Elisp: String Functions

repost.

• Elisp: Destructure Binding (seq-setq, seq-let)

• Xah Talk Show 2024-09-17 Ep586, Emacs Lisp, Rename All Links in Web Root Dir

added a common idiom

• Elisp: Walk Directory, List Files

• 2024-09-16
• Emacs: Xah Fly Keys 📦
• Major change. Removed xah-fly-shared-map. And xah-fly-key-map is now not declared obsolete.
• xah-fly-shared-map was introduced by Will Dey (and Dan Langlois) in 2020-04-18 during the key engine rewrite using set-transient-map.
• The idea of xah-fly-shared-map is that it serves as a parent of xah-fly-command-map and xah-fly-insert-map.
• This allows setting control modifier combinations such as C-t also be part of Xah Fly Keys binding, thus is automatically unbound when the mode is turned off, as it should.
• I think it makes things more complicated than worth.

• Xah Talk Show 2024-09-12 Ep585, Emacs Lisp, Find and Replace in a Dir, and Undo All

• 2024-09-12
• Emacs: Xah Find Replace (xah-find.el) 📦
• xah-find-undo-last-replace new.

new version out. buy it. thanks. Buy Xah Emacs Tutorial

updates

• Emacs Keys: Define Key
• Emacs Keys: Syntax

• Elisp: Hash Table

• Emacs: Xah Fly Keys. Escape Key

• Emacs: Input Method

• Emacs Init: Whitespace Mode

• Emacs: HTML Entities. Ampersand Encoding, Decoding 📜

• Emacs: Insert Emoji
• Emacs: Insert Unicode Character

• Emacs: Show Holidays

• LISP Girl

• Xah Talk Show 2024-08-30 Ep581, Emacs Lisp Coding, Command to Rename Variables, Paul Graham Website Tech 1999

• 2024-08-29
• Emacs: Xah JS Mode (JavaScript) 📦
• xah-js-eval-line and xah-js-eval-region now take universal-argument, to insert result in buffer.

• 2024-08-29
• Emacs: Xah PowerShell Mode 📦
• new. xah-pwsh-eval-region, xah-pwsh-eval-current-line

• 2024-08-29
• Emacs: Xah Wolfram Mode 📦
• xah-wolfram-eval-region and xah-wolfram-eval-current-line can take universal-argument to insert result to buffer.

• Emacs: Cycle Color Theme, Toggle 📜

• Xah Talk Show 2024-08-27 Ep579, Web History WHATWG vs W3C Split, Emacs Lisp HTML Convert PNG to JPG

• Emacs: Real Automatic Save File
• Emacs: #auto-save# (hashtag filename)
• Emacs: Refresh, Revert File

• Emacs: Zip Dir in Dired 📜

which editor by default highlight the current line? vscode, sublime, textmate, or other?

updated

• Emacs: Insert Date Time 📜
• Emacs: Interactive Abbrev 📜
• Emacs: fido-mode (Minibuffer Name Completion)

• Xah Talk Show 2024-08-22 Ep576, Emacs Lisp Coding, Toggle Theme, Print List, ErgoEmacs, Gun Emoji

updates

• 🆕 Emacs: Xah Fly Keys. How to Indent
• Emacs: Xah Fly Keys. Key for Org-Mode

• Emacs: Launch
• Emacs: MacOS: Start Emacs from Terminal

updates

• Emacs Init: Intro
• Emacs Init: Ignore Init File
• 🆕 Emacs Init: Timing Startup Time
• Emacs: Microsoft Windows Tips
• 🆕 Emacs: Microsoft Windows: Install Linux Tools

• Elisp: Association List
• Elisp: Sequence. Join, Convert
• Elisp: Apply Function (List to Args)

• Elisp: load, load-file, autoload
• 🆕 Elisp: Load Path

• Emergency vim
• vim, 3 Decades Pile of History
• History of vi Keys
• Arrow Keys: vim HJKL vs Inverted T
• Interview with Bill Joy (creator of vi)

• LISP Trump

• Emacs Fun Index

updates

• Emacs Init: Set Default Window (frame) Size
• Emacs Init: Sample Init
• Emacs Init: Set Color Theme
• 🆕 Emacs Init: Set Background Color

• Emacs: Xah Fly Keys. Key for Org-Mode

• Emacs Init: Organize Init File
• Elisp: Get Script Name at Run Time, Call by Relative Path

more updates.

• Elisp: Sequence Functions
• 🆕 Elisp: Sequence. Union, Intersection, Difference
• Elisp: Sequence. Map
• Elisp: Sequence. Find

• Emacs Regex Quirk: Matching Beginning/End of Line/String/Buffer

• Origin of Line Wrap at 80 Chars (Punched Cards)

• Emacs: Byte Compile Elisp Files

master emacs lisp loop and iteration. major updates.

• Elisp: Loop
• Elisp: List Iteration
• Elisp: Sequence. Iteration Guide
• Elisp: Sequence. Filter
• 🆕 Elisp: Sequence. Foreach
• 🆕 Elisp: Sequence. Insert or Remove
• 🆕 Elisp: Sequence. Map
• 🆕 Elisp: Sequence. some, every (conditional exit)

• Elisp: Exit Loop or Function (throw, catch)

• Xah Talk Show 2024-08-15 Ep575, Emacs Lisp, Command to Add HTML Attribute

• 2024-08-13
• Emacs: Xah Wolfram Mode 📦
• xah-wolfram-eval-region now work on current text block when no text selection.

Emacs org mode security emergency

just org mode is affected, not emacs.

but there's new emacs release, emacs 29.4, that fixed the org mode problem.

• Emacs: Download

• Xah Talk Show 2024-08-11 Ep573, Emacs Lisp, Validate Matching Brackets, Part 2

• Elisp: Validate Matching Brackets 📜

• Xah Talk Show 2024-08-10 Ep572, Emacs Lisp, Validate Matching Brackets

updates

• Emacs: Launch
• Emacs: Microsoft Windows: Start Emacs from Terminal

• Elisp: Sequence. Iteration Guide
• Elisp: Buffer Functions

• 2024-07-25
• Emacs: Xah Fly Keys 📦
• xah-close-current-buffer now also record dired buffer, so can xah-open-last-closed

• 2024-07-25
• Emacs: Xah HTML Mode 📦
• new: xah-html-insert-page-template , xah-html-move-text-block

• Xah Talk Show 2024-07-24 Ep566, Emacs Lisp, add twitter cards to 10 thousand files

• Emacs: Jump to Previous Position

• Xah Talk Show 2024-07-22 Ep564, Emacs Lisp Coding, highlight duplicate links

new. pepe anti emacs pill

• Emacs Fun Index

• Xah Talk Show 2024-07-19 Ep563, Emacs Lisp Coding move-html-text-block and random chat

• Emacs Init: Dired Config
• 🆕 Emacs: Dired, Show All Subdirectories 📜
• 🆕 Emacs: Dired Show Human Readable File Size 📜

• Emacs: Search Text in Directory

• Emacs: List Matching Lines

• LISP Logo

• Emacs Keys: Change Minor Mode Keys

• Emacs: Open Python Doc 📜
• Emacs: Insert Random Number or String 📜

• 2024-07-15
• Emacs: Xah Dired Mode (xah-dired.el) 📦
• xah-dired-toggle-human-readable-size new.
• xah-dired-metadata-remover-path renamed to xah-dired-exiftool-path

• 2024-07-15
• Emacs: Xah HTML Mode 📦
• xah-html-make-citation now use TORTOISE SHELL BRACKET.
• xah-html--get-youtube-id renamed to xah-get-youtube-id.
• xah-normalize-youtube-url new.
• image link functions now use xah-get-image-dimensions instead of calling imagemagick, unless necessary.

minor updates.

• Emacs: Xah Fly Keys Customization
• Emacs: Xah Fly Keys. Setup Keys for Major Mode

• Emacs: Messages Buffer
• Emacs: Principle, Command, Keys

• Elisp: Buffer Functions

• Xah Talk Show 2024-07-07 Ep560, Emacs Lisp Coding, Get Youtube Video Thumbnail

updates

• 🆕 Emacs: Microsoft Windows: Run PowerShell
• Emacs: Run Shell
• Emacs Init: Change Default Shell (PowerShell)
• Emacs: eshell

• Emacs: Key Macro Commands
• Emacs: Ido Mode (2007 to 2022)
• Emacs Init: Save Cursor Position

updates

• Emacs Init: Dired Config Emacs: File Manager, dired
• Emacs: shell vs eshell vs term

• 2024-07-03
• Emacs: Xah Fly Keys 📦
• xah-shrink-whitespaces minor refactor. removed xah-delete-blank-lines, xah-fly-delete-spaces

• 2024-07-05
• Emacs: Xah HTML Mode 📦
• xah-html-youtube-normalize-url now support query string.
• xah-html-keyboard-shortcut-markup better, now normalize command key opt key etc.
• xah-html-pop-back-source-code, xah-html-toggle-syntax-color-tags changed cursor position requirement. experimental.
• xah-html-change-current-tag changed cursor position requirement.

major updates

• 🆕 Emacs Init: Mouse Button Syntax
• Emacs Init: Mouse Wheel Config
• Emacs: Mouse Wheel Commands
• 🆕 Emacs Init: Disable Mouse Highlight
• 🆕 Emacs Init: Define Command for Mouse Click
• Emacs: Mouse Click to Highlight Matching Words