vim-sexp-mappings-for-regular-people VS coalton

The vim-sexp plugin does slurping and barfing of s-expressions. When I used it years ago with Clojure, c/o of tpope's fireplace plugin, I preferred his mappings for it.

I'm a vim user and generally dislike tools typing for me at the same time that I'm typing. I've gotten some value from https://github.com/tpope/vim-sexp-mappings-for-regular-peopl... though when writing Lisp.

vim-sexp-mappings-for-regular-people [1] uses really easy-to-remember shortcuts for these:

- "backward slurp" is "<(" (move opening paren to the left)

- "forward slurp" is ">)" (move closing paren to the right)

- "forward barf" is "<)" (move closing paren to the left)

- "backward barf" is ">(" (move opening paren to the right)

[1]: https://github.com/tpope/vim-sexp-mappings-for-regular-peopl...

I think the paredit stuff is a bit overblown but apart from managing parens for you, another simple example is editing single expressions. e.g. in Java you might have a line: "int a = blah.bar(something, thing, whatever);" If you realize you need to actually pass "whatever" first, not last, unless you know an IDE shortcut that can make the edit for you, you're going to have to type stuff. I would probably just move my cursor to the start, type "whatever, ", move my cursor to the comma after "thing" and highlight to the end then delete. If "whatever" was a longer variable, or even more interestingly an entire sub-function call like "whatever(x, y, z)", I might instead highlight it all, cut, backspace the comma, move cursor to the start, paste, type a comma. Oh no, I might miss a comma or somehow mess up a paren/semicolon or typo a name?! Whatever, it's rare for me, and for most mistakes I'd get a red squiggly alerting me to it immediately. I like typing, and prefer most 'helpful' plugins get out of my way for most things, so such a process isn't that annoying to me.

But I do at least see there's a nicer process if you have something like paredit: you just move you cursor to the "whatever" (even if it's instead "whatever(a,b,c)") and a command will move it to the left/right/etc. and fix up anything that needs fixing up. In Lisp though the base syntax is so simple and uniform that there's not usually much needing "fixing up" -- there's no pesky commas to deal with for instance, and having the opening paren come in front of the function name instead of after simplifies a lot of things. The worst is adding/removing/moving a form that's at the end of a let binding, or perhaps sometimes adding something to the end of a function that previously ended with ))).

I like to use vim (which does have paredit though I have it disabled) and just having the ability to jump between open/close parens by pressing "%" and to cut jumps as a whole, or the insides, without having to move my cursor character by character, is good enough for me. I still use some paredit-like commands in some instances like moving forms around or in those "worst case issues" I mentioned but I use them with these mappings: https://github.com/tpope/vim-sexp-mappings-for-regular-peopl...

There are more advanced things but how much I care about them varies; I don't tend to need them for Lisp, though every so often I'll miss something from Eclipse that I suspect not even emacs does (or does well). e.g. I know emacs can do a "templateized" completion just like a Java IDE when you type a function name and insert its arguments as placeholder variables to later define/type over, I don't know though whether emacs can then let you place the cursor over each one in turn and with something as easy as 'ctrl+1' hoist that var to an assignment form just above (I did this all the time in Eclipse to avoid having to choose a name, type it, and type its correct type). (In Lisp it's complicated by needing to introduce a let binding if it doesn't exist or append to one if it does. It wouldn't surprise me if paredit can do this, it's just that I'm aware of some refactoring tools in Slime but they don't tend to approach what Eclipse or IntelliJ users expect even if in theory they could.)

I use vim with slimv, paredit turned off but a few bindings from https://github.com/tpope/vim-sexp-mappings-for-regular-people are useful.

Slimv comes with a Paredit Mode: https://github.com/kovisoft/slimv Personally I leave it off, though, never been a fan of anything trying to 'help' me automatically while I'm typing apart from indentation. I do appreciate vim-sexp occasionally with these mappings: https://github.com/tpope/vim-sexp-mappings-for-regular-peopl...

https://susam.in/blog/lisp-in-vim-with-slimv-or-vlime/ is a good overview of the differences between slimv and vlime (the two vim plugins) and how to use them.

It's still… not the same. In CL (and specially with SBCL), we get compile time (type) errors and warnings at the blink of an eye, when we compile a single function with a keystroke (typically C-c C-c in Slime).

And there's also been improvement, see Coalton for a ML on top of CL. (https://github.com/coalton-lang/coalton/)

For the parenthetically inclined among us, there's also an implementation in Coalton: <https://github.com/coalton-lang/coalton/tree/main/examples/t...>

Common Lisp has bad marketing (even OCaml has Twitch streamers and "influencers" now), and bad support for general editors, both of which make it a non-starter for most curious people who have an afternoon to try something. But behind all that is magnificent activity for those who got over the initial potential energy barrier. Just to give some examples:

1. SBCL, the most popular open source implementation of Lisp, is seeing potentially two new garbage collectors. One of them is a parallel collector written by a university student (!!) which blows my mind.

2. SBCL has better and better support for deploying Liwp as a C-compatible shared library, using SBCL-LIBRARIAN. It makes it play nicer with other applications in C and Python.

3. Coalton is another exciting development that allows a Haskell type system and "Lisp-1" functional programming in Common Lisp. That means type classes (or traits), something Lisp hasn't really had a proper notion of, and full type inference. Persistent sequences based off of RRB-trees were recently merged, and interestingly, they're implemented purely in Coalton [1]. That means Clojure-like seqs.

It's interesting to see users of Lisp generating the above ideas and libraries, not a special in-group of committees, "official" developers, etc.

[1] https://github.com/coalton-lang/coalton/blob/main/library/se...

Use an editor that auto-inserts parens and that indents the code correctly. Now nothing bad can happen. And the parens are used to edit code structurally.

re typing: Coalton brings Haskell-like typing on top of CL. https://github.com/coalton-lang/coalton/ Other lisps are typed: typed racket, Carp… and btw, SBCL's compiler brings some welcome type warnings and errors (unlike Python, for instance).

If you like type safety, this project would be perfect for using https://coalton-lang.github.io/ so your REPL supported Common Lisp out of the gate.

Agree that you can use types to express and prove logical properties via compiler; it can be a fun way to solve a problem though too much of it tends to frustrate coworkers. It's also not exactly "low cost"; here's an old quip I have in my quotes file:

"With Scala you feel smart having just got something to work in a beautiful way but when you look around the room to tell your clojure colleague how clever you are, you notice he left 3 hours ago and there is a post-it saying use a Map." --Daniel Worthington-Bodart

> On the contrary, they're still the most effective technique we've found for improving program correctness at low cost.

This is not borne out by research, such as there is any of any quality: https://danluu.com/empirical-pl/ The best intervention to improve correctness, if not already being done, is code review: https://twitter.com/hillelogram/status/1120495752969641986 This doesn't necessarily mean dynamic types are better, just that if static types are better, they aren't tremendously so to obviously show in studies, unlike code review benefit studies.

My own bias is in favor of dynamic types, though I think the way Common Lisp does it is a lot better than Python (plus Lisp is flexible enough in other ways to let static type enthusiasts have their cake and eat it too https://github.com/coalton-lang/coalton), and Python better than PHP, and PHP better than JS. Just like not all static type systems are C, not all dynamic type systems are JS. Untyped langs like assembly or Forth are interesting but I don't have enough experience.

I don't find the argument that valuable though, since I think just focusing on dynamic vs static is one of the least interesting division points when comparing languages or practices, and if we're trading experience takes I think Clojure's immutable-by-default prevents more bugs than any statically typed language that is mutable by default. It's not exactly a low cost intervention though, and when you really need to optimize you'll be encouraged by the profiler to replace some things with Java native arrays and so on. I don't think changing to static types would make a quality difference (especially when things like spec exist to get many of the same or more benefits) and would also not be a low cost intervention.

Last quip to reflect on. "What's true of every bug found in the field? ... It passed the type checker. ... It passed all the tests. Okay. So now what do you do? Right? I think we're in this world I'd like to call guardrail programming. Right? It's really sad. We're like: I can make change because I have tests. Who does that? Who drives their car around banging against the guardrail saying, "Whoa! I'm glad I've got these guardrails because I'd never make it to the show on time."" --Rich Hickey (https://www.infoq.com/presentations/Simple-Made-Easy/)

Coalton seems great, I love the idea. This issue seems problematic, though: https://github.com/coalton-lang/coalton/issues/84

> Lisps can be very flexible, but they usually lack static type safety, opening a wide and horrible door to run-time errors.

People should do basic research before writing something silly like this. Qualifying your statement with 'usually' is just a chicken sh*t approach. Common Lisp and Racket have optional strong typing, leaving the responsibility and choice to the developer. Common Lisp is great for implementing compilers. You also have thing like Typed Racket and Coalton. The latter is comletely statically typed ala MLTON

https://github.com/coalton-lang/coalton

Have you checked out Coalton? It allows static typing a la Haskell within Common Lisp. Fully interoperable with CL, including through SLIME etc.

I've not regretted using Common Lisp for large, professional projects. However, I started Coalton so that some parts of a Common Lisp project can have strong, static, strict types—reaping benefits of compile-time errors and increased efficiency when I need it, without having to rewrite everything.