possibly.js

const [not, definitively] = [Symbol(), Symbol()]

export default const possibly = possibility => premise => alternatively =>
    [premise, ...possibility, definitively].reduce((premise, postulate) => 
        premise === not
      ?
        alternatively
      :
        postulate === definitively
      ? 
        premise
      :
        postulate in premise
      ?
        premise[postulate]
      :
        not
    )

Sorry I completely missed your actual function's functionality! 😆 It's cool. Ramda has a function like this called pathOr.

I don't agree that legibility is affected, but I also see value in what you're doing. I think the fact that in my code bases operator first applies to everything, from dot access, ternaries, addition/concatenation, logical and/or, bit shifting whatever... there's not really as much fighting on on the ternary operand expression. But I think if I wasn't so strict here, it'd seem noisier.

I am probably struggling to read your ternaries just because my mental algorithm for reading ternaries requires matching a certain pattern and I'd just need to internalize your pattern and then it'd seem just as good. But I'm generally pretty white space dense so I'm wary, but yeah it looks neat!

It's the Material Design Lite of code styles