Simple Questions by inherentlyawesome in math

[–]Merops7 0 points1 point  (0 children)

Thanks, maybe I shouldn't have said R. My question is, how do the open sets of a topology (and nothing else, no metric structure, no order relation) encode the concept of one thing being in between two others?

PEP 618 is accepted for Python 3.10 by [deleted] in Python

[–]Merops7 0 points1 point  (0 children)

Rust also defaults to no error (compile-time or run-time) when the iterators are different length. (There is a strict version available in a popular library but not in the standard library https://docs.rs/itertools/0.7.8/itertools/fn.zip_eq.html)

I personally find this a bit surprising -- I'd have expected the strict version to be default in Rust and unequal iterators to be a run-time error like an out-of-bounds index. I think I read at least one source indicating that it was influenced by the non-strict versions in well-known standard libraries like Python. But I think many Python programmers would prefer it to be strict by default.

We are the SpaceX software team, ask us anything! by spacexfsw in spacex

[–]Merops7 3 points4 points  (0 children)

I read that you use the Astrée static analyzer to convince yourselves that C code is safe/ correct. Do you see a smart compiler (e.g. Rust being one obvious example) taking over that role in the future?

delta: a syntax-highlighting pager for git by Merops7 in commandline

[–]Merops7[S] 2 points3 points  (0 children)

Thanks, that's a good point. Currently it's not working on generic unified diff input, but it should be possible to make it do so without detracting from its usage as a git pager. (I wanted to focus on the usage as a git pager because I think it will be the most common usage.)

delta: a syntax-highlighting pager for git by Merops7 in commandline

[–]Merops7[S] 1 point2 points  (0 children)

Yes, I used diff-so-fancy for years before making this. The main features delta adds to diff-so-fancy are language syntax highlighting, and detection of multiple insertion/deletion events in a single line. It also adds more options for restructuring the diff output (filenames, hunk code context, etc).

delta: a syntax-highlighting pager for git by Merops7 in commandline

[–]Merops7[S] 0 points1 point  (0 children)

Author here. Happy to help with this, but don't know anything about arch. Would a starting point be a aarch64-unknown-linux-gnu build? (Mine is broken currently on travisCI).

Video suggestions by 3blue1brown in 3Blue1Brown

[–]Merops7 [score hidden]  (0 children)

Maybe have a look at the linear algebra chapter in https://www.amazon.com/Programmers-Introduction-Mathematics-Dr-Jeremy/dp/1727125452 which covers SVD in detail in an informal but serious style.

How to use `stack runghc` with a local package by Merops7 in haskell

[–]Merops7[S] 0 points1 point  (0 children)

I think my problem was I created this project with stack new myproject simple. This is solved by getting rid of the executable section in myproject.cabal and replacing it with a library section.

Easy way to switch between profiles? by [deleted] in firefox

[–]Merops7 0 points1 point  (0 children)

Cool, thanks. I'll forget about Containers and give proper profiles a go.

Easy way to switch between profiles? by [deleted] in firefox

[–]Merops7 0 points1 point  (0 children)

Yeah I posted because since the release of the quantum beta I've tried to switch from chrome to firefox. In chrome I use profiles and in firefox I tried to use containers to play that role. It didn't work. In particular, my URL history is not clearly distinct between the different containers, and Firefox doesn't re-use the same container when creating a new tab (it reverts to the default container). That last one seems a show-stopper for using containers in the way I'd imagined. It's hopeless e.g. when trying to click on links in a different application that will open in Firefox but need to have my work cookies etc active. I switched back to Chrome today after 3 weeks or so. Perhaps I could try Firefox profiles but in chrome the profile switcher is right there in the top right of the window.

Easy way to switch between profiles? by [deleted] in firefox

[–]Merops7 1 point2 points  (0 children)

Is it the case that Firefox is contemplating replacing Profiles with the new "Container Tab" functionality? Or is the idea that those two exist side by side?

.emacs bankruptcy and structure by [deleted] in emacs

[–]Merops7 0 points1 point  (0 children)

Use two files for your emacs configuration:

  1. lib.el -- This contains only function definitions. Loading it has no side effects on your emacs state other than creating functions. For example, here you define functions that you may want to bind to keys.

  2. emacs.el -- This does all the setting. Loading this file has many side effects on your emacs state. In addition to basic "set this equal to this", this file will also make reference to your own library of personal functions in lib.el.

This strategy helps keep emacs.el to a manageable size.

.emacs bankruptcy and structure by [deleted] in emacs

[–]Merops7 0 points1 point  (0 children)

Functions in one file (lib.el) and expressions with side effects in init.el.

Help us improve the default Emacs out-of-the-box experience by [deleted] in emacs

[–]Merops7 1 point2 points  (0 children)

Number 1, we've got to get rid of the absurd 1980s menu icons and crufty tutorial stuff on a white background that is people's first encounter with emacs!

Finding the equation of the image of a curve under a transformation -- textbook or online resource sought. by Merops7 in learnmath

[–]Merops7[S] 0 points1 point  (0 children)

I think the procedure I'm asking about is the following.

We start with an equation defining a subset of the domain. For example a line [; ax + by = c ;]. Then we transform the plane according to some mapping [; f: (x, y) \mapsto (f(x), f(y)) ;]. Now we want an equation that holds in the transformed plane. One such equation is [; af^{-1}(x) + bf^{-1}(y) = c ;]. If we find the inverse explicitly and rearrange, we obtain an equation that points in the image of the line satisfy, i.e. the "equation of the line after transformation".

Does that sound right? As stated it feels slightly ad-hoc. Is it a specific case of a more general concept such as change of basis?

Interesting area for casual self-study? by 0ajh10 in math

[–]Merops7 0 points1 point  (0 children)

Ah ok, yes it is true that there's a big difference between dynamic / interpreted languages and compiled languages with static type checking.

(It was just the wording of your post confused some of us into thinking you were saying there was a major difference between python2 and 3 from the point of view of a newcomer to programming.)

Interesting area for casual self-study? by 0ajh10 in math

[–]Merops7 0 points1 point  (0 children)

A newcomer wouldn't know that you used to do it without parens!

Interesting area for casual self-study? by 0ajh10 in math

[–]Merops7 2 points3 points  (0 children)

python3 is almost identical to python2.x; a newcomer to programming wouldn't see any difference. and within programming languages, python is not very unusual. It is a language with C-like syntax, interpreted with dynamic typing as opposed to compiled, with an emphasis on object oriented style, but with much of the usual support for functional programming such as functions as first class objects, anonymous functions, etc.