How can I make variables that are not top level bindings?

[iconara]

The System guide says

Top-level variables defined in JavaScript cells, such as x and y above, can be referenced in other cells.

Which is very convenient in one way, but also inconvenient. I tend to use names like data many times and having to use unique names is slowing me down. Is there a way to make cells isolated and only expose a specific binding? I could wrap every cell in const someName = (() => { ... }()), but that is not very ergonomic. I think most of the time I want cells to be isolated with only specific exports.

[mbostock]

You can use a block statement:

{
  const data = …;
}

You can also just reuse variable names across cells. They don’t have to be unique in order to declare them; they only need to be unique when you reference them.

[mbostock]

Also, conventionally, you could use leading underscores to denote variables you don’t intend to reference across cells.

const _data = …;

[iconara]

Thanks. I wish there was a way to get Rust style block expressions like in Observable 1. I know I can opt in to Observable 1 syntax, but I also like that I can use vanilla JS/TS now. It's not a big deal.