I was thinking about possible syntax for it to be ...

# language-proposals

[kevinmost]

I was thinking about possible syntax for it to be a language feature and looked at some other languages. There's a language in development by Jonathan Blow for game development called Jai that has this feature. The syntax he chose is:

[scopedVarA, scopedVarB] {
    // function body
}

where only scopedVarA and scopedVarB would be accessible inside the function body