Xah Programing Blog
Syntactic obsession, imperative despisal, unicode ♥, hacker hate
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documenting time+space costs of computer language core operations
in my recent study of Programing Language and Its Machine i noticed that the cost of operation in programing lang is critical. i.e. each operator or func should have doc about its costs: a “cpu cycle” cost and memory cost.
low level programers, C C++ are intimately aware of the costs of each operator/function/statement. For scripting langs e.g. python ruby JavaScript not so much, but most know about it from list vs array vs hashtable.
one primitive way to get cpu+memory cost of each operation (the core operator, statement, function) of a lang is simply by profiling, and count cpu cycle and memory footprint. The result then normalized to have a scale say 1 to 10.
but, note that the cost also depends on the compiler/implementation, and the specific hardware. still, it seems reasonable to have a “score” of time+space costs for each and every core operations of a lang.
the explicit documentation of operation costs of computer langs have strong advantages. It makes all programers painfully aware. And that these costs are inherent, not man-made complexity. It also makes it trivial to know a program's efficiency.
Sometimes when coding, no matter what u do, there seems always a inelegant extra var, init, slot, assignment, push, copy …. When studying cpu e.g. Superscalar, RISC, CISC …, u see lots of cycles r wasted or memory copied vainly. So, “inelegance” seems INEVITABLE in algorithms.
creative domain names
in this 2010 article Intro to Video Codecs lots links are ded. One of them is .cx note that coder fashion idts who get creative with domain name. .cx is the earlist e.g. goatse.cx, then deli.cio.us then .io by google itself
2000 is the decade where things unknown to humanity are being seen. 'was, also the rise of 4chan, wikipedia, and caused the downfall of christianity, and rise of rainbow gay power with legality. Due to the uncensored n uncensorable internet. Unbeknownst to us all, this turned around into sensorship
2018-11-15 todo read about css cascade order. write tutorial
2018-11-08 todo golang, change the replace.go script so it reports changes
2018-11-13 todo. use js to to prevent right click. on chinese chess page. also make the button larger.
2018-11-13 rip Macross Plus “Information High”
2018-11-13 todo emacs, make the xah html mode, tag insert command, to not prompt, but instert class id etc directly.
2018-11-15 todo
prevent text selection
body {user-select: none;}
user-select:
- auto
- none
- text
- all
self-reference problem in programing
one thing i noticed in past 10 years coding is the self-reference problem. e.g. suppose u design lang string delimiter. say, python
"""triple quote"""
. That's safe enough right? until, you start to process python source code itself.
See also: Computer Language Design: String Syntax
similar problem is, when you use regex to match a regex string. The escape become a problem that is basically unsolvable. i think it's still mathematically possible in general, but practically not. e.g. emacs in cygwin trying to pass regex on file path regex to Windows's .exe
other problems are, html entities encode/decode, and url % encoding/decoding, and especially together e.g. ampersand in url. HTML ampersand is especially nasty. It has the property that it's mathematically impossible to tell if a string is in decoded/encoded state.
it's mathematically impossible to tell if a string is in html ampersand decoded/encoded state, when, your string is html text that discuss ampersand encoding/decoding, e.g. a tutorial of it. You need general AI or human, to tell.
recommend a svg book?
give my tutorial a try? Practical SVG Tutorial
it's condensed version of svg 1.1 spec covering the practical parts.
otherwise, i recommend https://twitter.com/AmeliasBrain 's books
SVG Essentials: Producing Scalable Vector Graphics with XML 2nd Edition, 2014, by J. David Eisenberg, Amelia Bellamy-Royds Buy at amazon
Using SVG with CSS3 and HTML5: Vector Graphics for Web Design 1st Edition, 2017, by Amelia Bellamy-Royds , Kurt Cagle, Dudley Storey Buy at amazon
she's also the author of svg 2 spec. Svg 2 isn't much adopted afaik.
golang: given byte index, find character index
given index of a byte slice, this is how to find the byte index that starts a character. (the byte slice may contain unicode)
solution:
for !utf8.RuneStart(textBytes[i]) { i++ }
given a index (of a char start byte) of byte slice, find the corresponding rune (char start) index.
solution:
utf8.RuneCount(byteSlice[0,index])
to add to Golang Tutorial
web dev work
lots work in past 2 weeks on CSS HTML. The tutorial is for quick start. It covers practical cases, concise explanation (without assuming you dummy), from my experience with html since 1995. No jargons, current design fads and jargon words. Xah Web Dev Blog
am wasting my life away
am wasting my life away. must remember, my long term goal, at this end stage of my life, say next 5 years or 10 if am lucky, is to achieve postdoc level of a geometry, and to understand proof systems, n write a compiler of my own lang. Near term goal is to complete js plot lib.
the way am currently running, is that anytime i'd depart this earth. and i don't actually have a plan. but but but btw, that's a painful thing to think about, but it's a matter of philosophy.
what's digital network audio amplifier?
there is a thing called digital network audio amplifier NAD D 7050 Direct Digital Network Amplifier i thought it's amplifying digital signals, but that doesn't make sense? it seems to do wireless audio, e.g. wireless speakers. How does that work? What protocol is that?
ideal syntax
lol. the last one is the most idiotic. it's spread by OOP fad since 1995, by the likes of java python ruby JavaScript
to understand the details of these syntaxs, see
Python = Pretentious Sheet
dug this up in my file ball. not sure i published it before. Python = Pretentious Sheet reading good!
Unicode Flags 🏁
given 250 country names, can you organize them by neighbors? i just did.
interesting that most country names in Africa ends in “a”.
most eastern euro country names also ends in “a”.
while doing the Unicode Flags page i get 250 countries and need to identify them. it's a wonder, you goto online map, and dip into street view. and see places of human animals.
Grouping Europe into Regions
i was trying to group flags into regions, unassuming, then, someone from Austria saw what i did, OMG what have you done! loool :D which country is central/eastern euro, it's complicated, really complicated.
just finished properly grouping european countries.
now, if somebodies complains about the order used, we need to declare war.
red/yellow kiwi, seed of kiwi is pungent
the seed of kiwi, has a sorta pungent taste. you can taste it when it's blended into liquid. and, amazing, amazon sell fresh fruit now buy kiwi
searching for kiwi seed, maybe chemical or other interesting read, you find red kiwi and yellow kiwi and kiwi seed oil kiwi seed
Chinese Chess
象棋，我脑🧠下不过电脑💻气死人😡 am pretty good with Chinese Chess since teens. but i can't beat computer program today.
just deleted my local copy of python 2 and python 3 docs on my site
i so despise python. and its doc is the worst among languages. see Python Doc Idiocies
Donald Knuth, Steve Jobs, and How Typography Sucks (on its own page)
Steve Job says, computer is bike for the minds?
a friend gave me his used bike. that's far better than $100 at walmart. but now, getting a bike lock, will cost $50. Any advice on bike lock? am looking at this Kryptolok 2 Mini-7 Bike Lock
~2015 i saw a video where young Steve Jobs talked about how human on bicycle is more distance/energy efficient than any animal. eagle or otherwise.
here's the vid https://www.youtube.com/watch?v=KmuP8gsgWb8
here's earlier diff one https://www.youtube.com/watch?v=ob_GX50Za6c (1.5 minutes)
i took a walk for 30 min and monologued about it. Note, bicycle itself won't do. You need paved roads. When you consider paved roads, the energy and effort required, bike then isn't exactly efficient, at all.
once you take paved road into account, then, there's the technology required for paved road. Also, all the precision machinery required for building a bicycle, e.g. gears, rubber on wheels, wire of breaks. that's really effort of thousands years of humanity.
then, the inspiration of “computer is bicycle for the minds” becomes silly. Note, the impetus of video tech are much due 2 pn. Much of Apple's success lies in human vanity. AI is driven by $ and military. $ and power, drives mankind.
The Python Unicode Mess
good articles.
[The Python Unicode Mess By John Goerzen. At https://changelog.complete.org/archives/9938-the-python-unicode-mess ]
and for in depth detail about this, see
[Practical Python porting for systems programmers, version 1.9 By Peter A Donis And Eric S Raymond. At http://www.catb.org/esr/faqs/practical-python-porting/ ]
See also: Python: Unicode Tutorial 🐍
paper ipad screen cover
there is such a thing. “paper screen cover” for ipad. amazon So that, when you use a pen to draw, it has friction like on paper, instead of gliding on glass.
Egyptian Hieroglyph 𓋇
𓋇
google web font refuse to show in @brave browser
google font https://fonts.google.com/ refuse to show if you are using @brave browser
i never actually use google font. i stick to Arial. I think we should just have 3 basics. serif, sans, mono. Font should be ban'd. and fakwestern alphabetical ignoramus tech geekers. i knew am gonna get lots drivels about this from the hacker types
http://rezich.com/ roboto is nice. it's logical and geometrical and simple, as most google's designs tends to be inhuman. i was thinking of using it few years back but decided don't want to have user download it. and these days, i wouldn't use anything google.
Apple not supporting SVG
it's interesting that Apple is not actively supporting SVG. e.g. there's no default viewer.
See also: Practical SVG Tutorial
my typical daily todo
todo today (this is the typical daily todo for me)
- need to work on compiler. study go compiler
- look into the implementing editor in 1k c golang
- get on with js plot
- understand proof systems
2018-11-01 todo. write about
div {all: revert}→ set it to browser's default. Note supported by Google Chrome as of 2018-10-19div {all: initial}→ set it CSS's default value. e.g. initial value ofdisplayisinline, regardless what element it is. But in browser, it'sblockfordivandinlineforb.div {all: inherit}→ set it to inherit.div {all: unset}
2018-11-01 finish
- HTML: Input Tag
- HTML: Select Tag
- HTML: Textarea Tag
- HTML Form Example
- HTML: Viewport Meta
- HTML: using “Object” tag for “Iframe”
- Test Page of HTML “abbr” Tag
need to go thru all links in HTML5 Tags Complete List and make sure all has examples of those none.
todo mod gen sitemap go script to also add sitemap page Xah Code Sitemap
and math.
2018-11-01 add sidebar Lisp, Python, Perl, Ruby Code to Validate Matching Brackets
fix audio links Lojban and Chinese, A Word A Day
separate into python and perl pages Python, Perl: Script to Check HTML File Size
2018-11-08. to study https://jsfiddle.net/walipini_air/y82usfno/
2018-11-08 write a tutorial on css order
clean up my js curve code
Google auto log you into the Google Chrome
stop using google chrome browser. it auto log you in into Chrome browser. That means, they can track every page you visit. Also, by using Google Chrome, they can track everything you do. But with the auto login, it gives them a legally defendable reason to do so.
[Why I'm done with Chrome By Matthew Green. At https://blog.cryptographyengineering.com/2018/09/23/why-im-leaving-chrome/ ]
i recommend brave browser instead. am using it.
much update
Understand ASCII Control Characters
here's ASCII Table
as scientific programer, I wasn't too familiar with it for the first 10 years coding with Mathematica, in 1990s. Then from 1998 to ~2007, i did java, perl, python, php. Still don't know ascii control sequence much, except line feed (aka newline), form feed, horizontal tab, carriage return.
But as you code more or touch low level issues, you have to know it well. e.g. even in JavaScript golang
why is ascii important? because when you do networking, protocols, terminal, IO, file encoding, or even syntax detail of programing languages, understanding ASCII control sequences becomes critical.
here's some issues related to ASCII.
- Emacs: Newline Representation ^M ^J ^L
- Linux: Terminal Control Sequence Keys
- ASCII Character Symbols ␀ ␣ ¶
note, ASCII is part of Unicode. In utf8 encoding, any file in ASCII encoding is 100% same with utf8, if the file does not contain non-ascii chars such as ∑ α → 😂
note that, the need to understand ASCII is one thing, meanwhile, there are lots programers, typically mono-lang American, who have phobia towards any non-ascii character. They insist, that programing language source code should not contain ANY char that keyboard cannot type directly.
[see Problems of Symbol Congestion in Computer Languages; ASCII Jam vs Unicode]
emacs dev Alan Mackenzie is one such person, and many others in emacs dev list. They, resulted a damage to emacs around 2016. So that now emacs function doc string has the complexity of going thru transformation, instead of “curly quote” directly.
it is Alan Mackenzie, who did the deed. after hundreds of flamewar messages, then, it is Richard Stallman, sealed the damage. rms was not a emacs maintainer at the time, and supposedly he does not have the authority for final decision on anything none political. Maintainer was Stefan Monnier
what's the problem of using some form of encoding for none ascii chars?
Using encoded form is unreadable when you have lots of them. And it adds complexity of a transformation step.
e.g. in math, → ∑ α etc.
not
→
∑
α
etc in html.
or worse in TeX escape or
\xhhhh
\xhhhhhh
in many langs.
or consider euro lang. é and other. Basically, when you have several of that in a sentence, using encoded form is not practical. you have unreadability, and complexity of conversion, which easily go wrong, e.g. encoded/decoded twice.
imagine, if Spanish people had to write niña by ni＆ntilde;a or ni\x00f1a. Or French has to read télé from t＆eacute;l＆eacute; or t\x00e9l\x00e9. That is what programers who insist on ascii-only source code r asking.
just wrote a profile on my patreon https://www.patreon.com/xahlee thank you all for putting $ there
Great Software for Microsoft Windows ancient list.
as you blog and time marches on, pages become a record of history.
best thing for a nerd fanny pack
when coding JavaScript, do you prefer 'single' or "double" quote for string by default?
vote on twitter
https://twitter.com/xah_lee/status/1054883448437977088
xahlee info traffic rank 2018-10-23
climbing the ladder
word of the day is: arduous. #xahwords
to read. erlang tutorial https://learnyousomeerlang.com/starting-out-for-real
support my work. buy yourself a 512GB SSD Buy at amazon
or Put $5 in my patreon. https://www.patreon.com/xahlee
book
[Best Ever Paper Airplanes By Norman Schmidt. At Best Ever Paper Airplanes]
Programing Language Idiocy: Bit Operators (on its own page)
Necessity of Operator Overload in Computer Languages (on its own page)
hex screw kit
hex screw kit, so that u can open apple stuff that apple no want u do amazon
w3c dead link
dead links record trail:
when you learn a programing language, do you watch video lecture/presentation?
- love video format
- sometimes
- almost never, prefer read
vote on twitter https://twitter.com/xah_lee/status/1053468710617272321
and, programers, eat walnuts, live forever. buy walnuts you buy, you eat, i live. Yes it's an ad. out of my own volition.
ML stands for?
when i see the abbreviation ML, i think of Meta Language, the grand daddy of SML, CaML, OCaML, FSharp, Clean, Miranda, Haskell. ML were invented for automated theorem proving. Machine learning?? you mean like smart guessing?
brave browser still have the bug, where sometimes the url field shows the url from a different tab
What's Function, What's Operator? (repost)
new book. The Little Typer
new book. The Little Typer The Little Typer, 2018, By Daniel Friedman et al.
Friedman is one of the top lang researcher. He's 74 now. So am not sure he's actually the main author.
Friedman wrote a series of books titled “Little Schemer”, “Little Java”, “Little Prover”, “Little MLer” etc. Daniel P Friedman Books I read Little Java back in 2000. Wasn't comprehensible to me. I never liked these story-telling style books.
why not perl6?
What Lib Did You Use? None!
you can buy a slingshot, to shoot down drones slingshot
todo remove reference to python ruby etc at Perl by Example
do same for
on this page Perl Books Survey 2002 make those gz local copy files as html
to read kilo. text editor in 1k lines of c https://github.com/antirez/kilo
it golang https://github.com/bediger4000/kilo-in-go
https://viewsourcecode.org/snaptoken/kilo/05.aTextEditor.html
essay about guido the character Transfer of Power (Guido stepping down as BDFL) https://www.reddit.com/r/Python/comments/8yapie/transfer_of_power_guido_stepping_down_as_bdfl/
esr, on porting reposurgeon from python to golang
great article by esr. on porting reposurgeon from python to golang http://esr.ibiblio.org/?p=8161 reposurgeon is software for converting cvs/svn to git. many points he touched about python and go, i agree. python's future is bleak
many point esr mentioned i concur.
- golang 's treatment of string and unicode is a miracle.
- the creation python 3 is a misery. botched in many way.
- python (and ruby)'s future, is really bleak, in light of go.
- it's easy, to port python software to go.
Note that python became popular, when Google decided to use it ~2000. There wasn't much choice. It or perl. Python lost to php ruby for web dev, and to nodejs in late 2000s. Python is popular now because again Google used it in early 2010s for data analysis and machine learning.
python's warts and slowness and parallel computing problems can't be solved by the lang itself. go, crystal, nim, julia, trivially blast python to bits.
typed vs untyped lang
now am of the opinion that programing languages should be typed. (modern system, eg golang. not C, C++, Java). When younger, i thought it should not, cuz i considered typing as by-product of compiler.
in some sense, typing is a unwanted by-product of computer engineering aka compiler. and, it was so, up to 2000. However, with different perspective, a proper type system, is like a good property of logic system. For programing language, it improves correctness, bring clarity.
there are exceptions. e.g. Mathematica (aka wolfram lang), where the computation model mostly is a symbolic term rewriting system. So, typing system does not apply. (btw, lisp is almost the same, except lispers since 1990 are extreme idiots. they r C coders in paren clothing.)
just removed all disqus comment system on my site. they've become greedy, forcing image ads, in order to survive. but their ads, are the lurid ones.
Chinese abacus. they have 2 beads on top, 5 below. i never learned their exact function of the “extra” beads. In Taiwan, we grew up with Japanese style, 1 on top, 4 at bottom.
more pic https://twitter.com/Echinanews/status/1050284413504774144
but apparently, the 2 5 setup allows computation with hexadecimal, which is a traditional chinese weight system.
interesting that D lang is still going. “Alexandrescu (i think he's 2nd in D language dev) worked as a research scientist at Facebook, before departing the company in August 2015 in order to focus on developing the D programming language.”
google shutting down google plus
google shutting down google plus, over the next 10 months.
since google began g+ in 2011, i'd say it marks the year google goes evil. then, its worse and worse, starting with greed, to now heavy censorship and explicit and blatant political gaming.
a great sadness to witness google over the decades. we helped google succeed back in 2000, since it was the company that does no evil, different from all others.
added a realistic survey by jetbrains
old writing, new page. work in progress
to read https://getstream.io/blog/how-a-go-program-compiles-down-to-machine-code/
Programing Language and Its Machine (to be expanded)
Chinese spy chip found in Apple Amazon server motherboards, said.
https://www.theregister.co.uk/2018/10/04/supermicro_bloomberg/
https://twitter.com/htommy998/status/1047928532100210688
Apple's response https://www.apple.com/newsroom/2018/10/what-businessweek-got-wrong-about-apple/
Amazon's response https://aws.amazon.com/blogs/security/setting-the-record-straight-on-bloomberg-businessweeks-erroneous-article/
stupid ipad. i have a old ipad. when viewing some page , requiring 100+ pushes to scroll down. Is there a way to drag the scroll bar?
on android, when u swipe fast, the page flies like on wheels. On iPad iOS, it's like stuck in some viscous shet. i think iOS UI is idiotic.
ImageMagick Tutorial (minor update)
programing language speed comparison
interesting. look at golang, the optimized version at bottom, beats all. and look at how slow are python ruby php.
Recursive fibonacci benchmark using top languages on GitHub
i can't tell wtf is that.
this is what online forum looks like, before Facebook
https://forums.somethingawful.com/showthread.php?threadid=3846735
biological computer, dna, molecules
i took a microbiology class in 1996 or so, of things like the vid is talking about. understand cells, what's inside, what they do, how they work.
The molecules, when a bunch of them are together, they bind in a specific way, some like that. gazillions megalions at the same time. This is what is meant by biological computer. mega parallel.
in 1990s, i recall Knuth said computing/algorithm is not interesting cuz it's already filled. and biology is far more interesting. That remark lodged in my mind. I now doubt it, but still, biology is fascinating. I think, to me, beats physics actually.
memories. this is where i live. Netscape headquarter was just 15 min walk away.
the verge pushing sj, building a PC
theverge dot com pushing sj. the video is here https://www.youtube.com/watch?v=jciJ39djxC4
Buy Xah Code
http://xahlee.info/ is now 16.4k files, 1.2 GiB. 5k html pages of math and code and history of the hacker cult. Take 4 years to read it, and you'll be a doctor of philosophy. You, buy it now!
Lenovo Yoga 720 laptop. good.
buy Lenovo Yoga 720DuckDuckGo = lack luster
now half of the time i search something, @DuckDuckGo gives me this error:
If this error persists, please let us know: error-lite@duckduckgo.com
(this happens when I'm using brave browser with JavaScript off by default, and ddg as default search)
am thinking abandoning it.
duckduckgo is such that, if you search for something easy, something typically you'd expect from 1st result, then u get what u want. But any slightly rare search, or research, its lack luster. you resort back to google.
OCAML's Official Tutorial Blatantly Suck
finally fixed.
is there a JavaScript util similar to golang's gofmt? note, i want it to be able to cut long lines of code. e.g. if entire code is in 1 line, make it multiple lines with indentation.
const declaration, for programer or for compiler?
in JavaScript and golang, there's “const” declaration. Am starting to think, it's more used as programer guide than for compiler, because compiler most of the time would automatically optimize var that doesn't change. Is this true?
don't use Google Chrome browser
these days i don't use Chrome except ONLY for google account. The google browser, can trivial do things even if u turn off all cookies and javascript and don't login to any site. Nobody would know except google.
context, google chrome posting about it's 10 year anniversary. https://twitter.com/googlechrome/status/1037038838550601734
[There is no pass-by-reference in Go By Dave Cheney. At https://dave.cheney.net/2017/04/29/there-is-no-pass-by-reference-in-go ]
This is a great article. Apparently, that guy blog a lot about golang, seems to be a go expert.
golang, should i return big string or save it to a var pointer?
am wondering if i should do
outBytes=genSiteMap(inDir)
or
genSiteMap(inDir, &outBytes)
the 2nd ceases to be function programing, but i guess is more traditional C C++ D go stuff.
Give me your opinion.
design of how to deal with errors in programing languages
[The Error Model By Joe Duffy. At http://joeduffyblog.com/2016/02/07/the-error-model/ ]
seems a great article.
Franz Lisp, number 1 commercial implementation of Common Lisp
Franz Lisp, still alive! It was, or still is, the number 1 commercial implementation of Common Lisp.
Unicode Box Lines ┌ Blocks ▓ major update
programing languages ranked by ease of learning
cutting thru golang like a chainsaw thru snow! smooth. of langs, similar experience is php. And worst is python. for ease of learning to practical depth, the order is: golang ≻ php ≻ python ≻ JavaScript ≻ perl ≻ clojure ≻ java
golang is definitely more verbose than python or ruby. For language verbosity, the order is roughly this: C ≻ java ≻ golang ≻ JavaScript ≻ php ≻ python ≻ clojure ≻ perl ≻ Mathematica
python is a lang against functional programing, worse than perl.
- Why Python's Lambda is Broken and Can't be Fixed
- Python, Lambda, Guido: is Language Design Just Solving Puzzles?
- Lambda in Python 3000
everytime i say it, some python fanboy will counter, python support functional programing. Right, it does, like every lang do. But in practice, even the lambda is crippled. And if you use functional programing libs, other coder looks at you funny.
If you have a question, put $5 at patreon and message me.