Genuine question: Why not use already existing syntactic conventions a-la for of ?

[lichrot]

Not to sound dramatic, but I'm very concerned by the fact that using breaks already existing intuitions of JavaScript syntax.

Specifically, using messes with variable declarations (let/const/var), while await using gives a false impression of awaiting something on the line it has been used (i.e. it looks like it awaits a possible promise on the right-hand side of the assignment).

Here's an example of syntax that actually fits already established conventions:

const getResource = () => ({
  [Symbol.dispose /* Symbol.asyncDispose */]() { /* do disposal */ }
});

// inline
const resource = getResource();
try {
  /* await */ resource.doSomething();
} finally {
  /* await */ resource[Symbol.dispose /* Symbol.asyncDispose */]();
}

// with keyword
using /* await */ (const resource of getResource()) {
  /* await */ resource.doSomething();
} // `resource` gets disposed here, clear and simple

// with iterators
const getIterResource = () => ({
  [Symbol.dispose /* Symbol.asyncDispose */]() { /* do disposal */ }
  [Symbol.iterator /* Symbol.asyncIterator */]() { /* do iteration */ }
});

for using /* await */ (const resourceChunk of getIterResource()) {
  /* await */ processChunk(resourceChunk);
}

I do not claim to be qualified or provide a comprehensive and robust solution here, but at the very least this example attempts to work within already existing syntactic conventions.

[hax]

@yohgen There are 5 years long discussions about syntax, you could check the old issues, especially #15 and #76 .

[lichrot]

@hax Thanks for the pointers.