Hi! I've been following a lot of the discussions here, and to help inform these discussions, I wrote a tool that gets statistics of how the ?. operator is used in practice in real-world CoffeeScript projects. CoffeeScript includes basically all of the features under discussion (short circuiting, soaked new, soaked delete, soaked assignments, parens to block short-circuiting), so I think it's a good case study to see how these details play out in the real world.
(For a little more background about me, I've been the main person working on the decaffeinate project for quite a while now, and I implemented ?. and similar operations in decaffeinate, so I've worked with the nitty-gritty details of these operators quite a bit. My personal preference for JS optional chaining is to keep things simple; I was unpleasantly surprised when I learned how magical ?. is in CoffeeScript. But I'm a little biased because I've generally viewed this stuff from an implementer's perspective.)
Here's the repo: https://github.com/alangpierce/coffeescript-soak-stats
The README has a detailed explanation of the different stats when run on about 500,000 lines of "typical" code found on GitHub (Atom, ShareLaTeX, CodeCombat, SwitchyOmega, Trix, Vimium, YakYak, and Bacon.js). Here are the results:
Total files: 2489
Total lines: 475208
Total soak operations: 4627
Total soaked member accesses: 3811
Total soaked dynamic member accesses: 240
Total soaked function applications: 576
Total soaked new invocations: 0
Total soak operations using short-circuiting: 1522
Total soak operations using short-circuiting (excluding methods): 233
Total soaked assignments (including compound assignments): 37
Total soaked deletes: 1
Total cases where parens affected the soak container: 0
Total soak operations chained on top of another soak: 564
Some observations:
new was never used and soaked delete was only used once.(a?.b).c, it never came up in practice (probably because it would just make the code crash).a?.b = c) had some usages, although of course they were much more rare than other uses of ?..a?.b(), that would cover 93% of all use cases.a?.b?.c (which don't rely on short-circuiting) than a?.b.c (which rely on short-circuiting).So I think this is at least an argument for leaving out new, delete, and meaningful parens, unless they somehow makes things simpler.
Happy to dig into the specific examples for these or run other statistics if people want. And of course it's open source and published on npm, so feel free to hack on it or try it on your own CoffeeScript code. I was reasonably careful and there are tests, but it's still possible some of these numbers are buggy.
ljharb, rattrayalex, gisenberg, Fire-Dragon-DoL, d4nyll and 17 morexnnkmd and BridgeARrattrayalex, gisenberg, Mathspy, claudepache, keithamus and 7 more
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4