[BoppreH]

Try this exercise: change the first line into the second, with the cursor starting at the caret. Do it slowly and pay attention to each key you touch.

  lineTo((10, 35), (20, 15))
         ^
  lineTo((20, 15), (10, 35))

Maybe you had to hold Ctrl+Shift and mash the right arrow to select the first tuple, and then Ctrl+X. Or you typed "d2t,", paying attention to the inner comma. Probably between 10 and 20 movements, all over the keyboard. Three or four seconds, and to me feels like using a blunt knife.

And yet you are just moving one element down a list. You do it all day with parameters in a function, statements in a block, items in a literal list. Which is why it has a dedicated command in my editor: "Move down" (https://i.imgur.com/wvcduDk.png). It's a single key. Works in all cases mentioned, for all supported formats.

I'm not saying a structured editor is for people who forget semicolons. It's for people who have to work with semicolons.

[gumby]

That's a lovely example. I was going to post that I don't like structure editors, but your example is two keystrokes in Emacs: c-m-F and c-m-T -- which I now (after 35+ years) realize is a structure editor.

(one of the first things I worked on when I started at PARC was adapting an Emacs clone since I didn't like the Interlisp structure editor. Little did I know!).

[mkramlich]

again... I hear you. been there, done that, have the T-shirt, over 35 years of coding in multiple domains, including GUIs, graphics, games, code-driven visual layouts, etc.

and I'm saying with a low-overhead deterministic-optimized editor like vim, and the right person at the keyboard, this can be done very quickly and accurately. and again, to continue your example, the hard part is not getting the syntax correct it's ensuring the resulting visual image -- your example suggests a vectory visual artifact ala OpenGL or SVG, etc. -- has the right shape and position. Syntax is something my brain/eye system just tells me, instantly, RIGHT or WRONG. our brains are great at this.

I'm not saying you're wrong. I'm saying for non-newb, non-lame programmers it's a use case that optimizes for a cost that's one of the smallest costs imposed on the programmer. not unlike "premature optimization".

I'm not saying syntax-enforcing keystrokes are a bad thing. I do think there are benefits to having a set of syntax-generic consistent keystrokes, like vim, across all the various syntaxes one has to deal with, day in and day out. If the only thing I ever had to edit was C files or JSON, that's it, nothing else, then yes having a C or JSON-semantic keystroke-restricted inescapable mode (with prompts, wizards, etc.) would be a help. (Which arguably is how all the big fat modern IDEs have evolved towards anyway.) But I'm very aware of the phenomenon where one can gain in the small but lose in the large. Local maxima, etc.

Also benefits to having screen match print, etc. Being grep-friendly, diff-friendly, textual VCS-optimized friendly, etc.

Local maxima. The sneakiest wrongs are right in the small.

[girvo]

I don't disagree with you, but:

> non-lame programmers

How many programmers are out there that are "lame"? Honestly, I still to this day work with code written by developers with years of experience who still get syntax wrong. Often I forget that most skills follow a bell-curve, and most developers are not one-with-their-machine-and-language -- hell, even I'm probably not, although some days I might feel like it. I think having a system that removes that barrier would allow that vast sea of average programmers to move closer to that sublime moment where your thoughts are transcribed in code, perfectly, in one go.

[mkramlich]

> How many programmers are out there that are "lame"?

from a few decades of observation in the wild, I'm sad to say that it is a surprisingly large percentage. the market demand for programmers seems to exceed the supply of those of us who truly can.

[Dewie3]

I don't agree with the premise that structural editing is for developers that are (necessarily) subpar to begin with (see my other comment).

[mkramlich]

I do think the "killer app" use case for the modalities you're talking about are data entry kinds of use cases. Where a non-expert user, perhaps one who has to deal with a variety of formats, very randomly, is required to type things in that strictly confirm to a perfectly-defined syntax. And he/she has a gigantic amount of data to enter manually, by hand, in a short time. Higher throughput is better, but also highest correctness is the other dimension. Tiny percentage time overhead spent on thinking, design, test. Mostly on data entry by hand. Then yes your approach starts to yield disproportionately higher benefits.

Arguably one reason why XML/XSD/XSL took off. It was not just yet-another-structured-text-format like CSV and JSON. It also had an "official" way to express and constrain an application data format, and generic query and mapping languages. Great for low brain, high volume, high repetition use cases. However... programming itself is high brain, lower volume, low repetition.

[SomeCallMeTim]

Nice example, but...I work with graphics code a lot (I'm a game developer), as well as in tons of other domains. That operation wouldn't be worth the mental storage (and certainly not a key!) to memorize. I can't think of the last time I would have needed it. Maybe when getting a pair of function parameters in the wrong order?

The example you gave wouldn't ever be a program I'd write. Magic numbers? Hard-coded rendering? Rendering something that can't be edited by an artist? All bad. I understand that it's just an example, but can you come up with one that would be valid in production code?

I know you were looking for a simple example, but in addition to the comments others have made about syntax not being a big deal for an experienced developer, this looks like a helper operation for developers who are doing it wrong to begin with.

Aside from that, years of user-experience research shows that modal editors are worse than the alternative (if you can hit one key, that means you can't type text in that mode; sorry vim-lovers, but it's true).

Yes I tried your experiment, and I could get it down to 7 keystrokes in my editor. I type quickly, so that's a couple of seconds at most; less than a second if I'm in the zone. With how rarely I do that operation, I'd not bother trying to optimize it more (another comment mentioned premature optimization).

But if I did need to do it a lot, creating a new macro that did the right thing wouldn't be hard; in a couple minutes I could bind a simple version of the command to a key permanently. Also, if I were modifying many similar lines to change them, I have options: Refactoring tools (if we're talking a function signature change), simple keyboard macros, or smart multi-file search-and-replace regular expression conversions.

And all of this in a "text" editor with a low barrier to entry (unlike vim OR emacs) -- though one that understands some structure at least.

[unhammer]

Isn't d% a more likely vim command?

Although, you'd think vim would have a general "transpose text object" operator. If it were bound to some ŧ, then you could just do %ŧ% (here emulating Emacs' C-M-f C-M-t)

[lloeki]

Short of having a transpose verb, here is what I cape up with (using the arg text objext):

    dia      # 1. delete argument under caret
    df       # 2. delete separator (comma and space)
    %        # 3. move after argument (i.e to end of tuple)
    p        # 4. paste separator
    "2p      # 5. paste argument

I'm not doing this out of the desire of golfing but to analyse and point out that what vim lacks in this specific case is how to semantically do step 3 (ga/gA ?) and possibly step 2 (because what if there's no space? a "separator", like "surround", might be useful), upon which one could easily and semantically build a "ŧa" (transpose argument) sequence (which could also become ŧ2a, ŧ3a to swap with the second or third next argument, and capitalize the a to swap with the previous).

That said vim is still "only" a text editor, but it goes a long way at being a general purpose one with semantic operations.

[titanomachy]

Thinking structurally, I would use `da(`. Of course, `d%` is less keystrokes.

[shabbyrobe]

Using vim with the sideways (https://github.com/AndrewRadev/sideways.vim) plugin and the following mappings in .vimrc:

    nnoremap <silent> <leader>h :SidewaysLeft<CR>
    nnoremap <silent> <leader>l :SidewaysRight<CR>

I pressed two keys, job done: ,l

[smorrow]

Double click, type "20", double click, type "15", double click, type "10", double click, type "35".

(All without typing the actual quotemarks.)

If I had realised earlier that it's (x,y) to (y,x), I could've done it without the keyboard at all.