@Tim The FP use of "monad" is very narrow compared to the term in category theory

@Tim Scala is a messy hodgepodge, yes. I don't think that learning what it borrowed from independently is helpful to learning how those features are translated to Scala, or how they interact once they get there

@Fabby I don't know who starred this, but it's incorrect. It's not even clear what the subject is, but if it is the GNU Hurd, then there have been many releases.

And of course the GNU project consists of many components, and they have collectively had many releases over the years.

@MichaelHomer I think so too. I feel bad that many programmers' explanations I found try to make the concept easy to understand but end up with more confusions.

I have somehow managed to understand "monad" from category view in the past few days, with understanding some prerequisite concepts that lead to "monad" definition. I am still yet to come back to how the categorical concept applies to the feature in programming languages

M is a monad in the categorical sense (just a monoid in the category of endofunctors, what's the problem), and return/fmap/join defines a monad in the Haskell sense, but Haskell is a programming language and not a mathematical formalism

The FP sense of monad is better appreciated as a generalisation from List/Maybe/&c, or by way of applicative functors, rather than as a direct translation of categorical terms

Or even as bind/return rather than fmap/join

Personally I find the progression map ⇒ fmap ⇒ <*> ⇒ >>= useful for understanding how this all fits together, but bind & return much better for practical understanding of Monad as a typeclass and what it does for me

If you're really keen on the mathematical side, Agda may be more your speed than Haskell, but it's a nightmare to make actual programs in

Speaking of the Hurd, this is a relatively good xkcd. And since everyone posts them, I will too.

@MichaelHomer Do you write in Haskell? If so, what do you think of it?

@FaheemMitha I like it, but I don't practically use it much

I would like to more

I wonder why this deleted answer doesn’t show up in the list of recently-deleted posts — do deletions related to account removals not show up in the moderation tools?

@Tim when the project I’m writing documentation for has a style guide, I follow that, otherwise it’s personal style. The development style I advocate isn’t hyped so it doesn’t have a something-driven-development name ;-).

@MichaelHomer Thanks. I will be back to your comment. Meanwhile, I have posted some questions which are motivated while I read the book by Mac Lane. For example

There have been a few more basic concept questions too. I am just to give you some idea what I am at or what I have reached, not necessarily ask you to answer my questions over there

I haven't posted anything serious on math.se for quite a while

I imagine the category theorists can answer the category theory questions much better anyway

It is not my first time self studying a bit of category. It was quite a while ago. So my past vague memory does help me understand some new concepts now.

But this is my first time reading the book by Mac Lane. I read about category only from wikipedia quite a while ago, reading wikipedia article was my main way of learning at that time, I post questions mainly from not understanding something in wikipedia, and I still remember some user at math.se called me an avid wikipedia reader)

Learning by reading wikipedia articles has been challenging. Reading a book is more coherent and clear. I admit I only pick small parts of the book to read by searching the terminology that I encounter, bc I can't afford to read a book from page to page

@MichaelHomer Ok. What have you used it for?

achieving PhD, I suppose

doing research, of course

@Tim Oh. Not to write programs for a specific purpose?

Sorry, that should have been address to @MichaelHomer ^^

@StephenKitt I think you've guessed correctly

@JeffSchaller thanks! I couldn’t find anything on Meta.SE

I love that the question has comments from a deleted user

@StephenKitt the circle of deletion is complete :)

I must have recovered a bit of my Google-fu from Stephen

@JeffSchaller aargh, I didn’t hold on to it hard enough

@StephenKitt Thanks.

cat
hello world
ctrl+D

huh now my terminal is just sitting there below the

ctrl+D

line

@Jesse_b 👋 🌐

decent

/me wishes <kbd>Ctrl</kbd> worked in chat

@StephenKitt you saw my aborted effort, then

@Jesse_b exciting news -- next week is chainsaw week! I'll try to remember to take before (during?) and after pictures of the Charlie Brown tree-cutting

@JeffSchaller Decent. Good luck! Be safe

@JeffSchaller no, but I suspected you’d have used that if you could, and I wouldn’t have been able to joke about it

@StephenKitt but now you could ask a question on Stack Overflow: How do I exit the cat?

guaranteed HNQ, if it doesn't get closed

@JeffSchaller it might even attract a graphical answer from @Fabby ;-)

@JeffSchaller If you find a ball of hair, hold on to it and you will exit quicker.

Shouldn't be an issue as long as it's a tabby cat and not a spacey cat

I have vacation, but I do so many other things that I get about five hours of sleep every night. I'm dead tired... Which is why I'm not too visible here at the moment.

@Kusalananda If sleep where a drug it would be the most powerful performance enhancing drug known to man.

UUoC!

One does not simply use cat. Cat is in charge

That might be one of those timeout cats

wizardly insight there, Mr. Kitt!

@JeffSchaller we should have an automatic hint for questions containing “2.6.32-042stab”

@StephenKitt one stabbed, twice shy?

too bad the straight-forward search fails :(

@JeffSchaller yeah, a long time ago

I was going to tease you for "a year and a half" being "a long time ago" but I couldn't remember something from last week.

whew, this search is as close as I can get. The dash seems to throw it off.

better

and better -- only two questions to address :)

@JeffSchaller oh I thought you meant when I had run into this problem myself

well, you ran into the Answer -- good enough here :)

I think reading TeX documentation may burn my brains out.

@StephenKitt I just tried and [ctrl][c] exits the cat so that's not a very good question (cc @JeffSchaller )

(ulness we can package it in a Unix joke like:

man woman

trap '' 2

cat

@Fabby qph.fs.quoracdn.net/…

@Jesse_b :D :D :D

@Jesse_b Ah! Found it!

For someone to answer who knows ACLs and such things on Linux: unix.stackexchange.com/questions/529579/…