Pipe expression

💡 Ideas
1

Description

When we need to destruct array or object and change value then we need make something like this

let { first = "data", second } = getSomeObject();
first = computeFirst(first);

// Or create temporary useless variable

const obj = getSomeObject();
const second = obj.second;
const first = computeFirst("first" in obj ? obj.first :  "data");

I propose operator which will give ability to us to apply some function to property inside destruction-syntax without mutable or temporary variables

const { first | computeFirst = "data", second } = getSomeObject();

I think that syntax should be discussed, but it seems lie pipe-symbol is well-known operator in bash and in AngularJS/Vue community.

Alternative variants

Swap function and argument:

const { computeFirst | first = "data", second } = getSomeObject();

Use $ as separator:

const { computeFirst $ first = "data", second } = getSomeObject();

Use -> or <- as separator:

const { computeFirst -> first = "data", second } = getSomeObject();
// OR
const {  first <- computeFirst  = "data", second } = getSomeObject();

Usage

Function arguments conversion:

function getUserResult({ score  | BigInt }) { ... }

Node.js environment variables:

const splitted = a => a.split(",").map(a => a.trim());

const {
  REPOSITORIES | splitted,
  BRANCH = "master",
  COMMITS | splitted
} = process.env;

SQL result to JavaScript:

const { createdAt | Date } = getUser(id);