Shorthand syntax for supplying a parameter

[alex-snezhko]

It would be nice to have a punning syntax for passing a binding as a labeled argument with the same name

Possible syntaxes:

let add = (num1, num2) => num1 + num2

let num2 = 2
add(1, ~num2)
add(1, num2=)
add(1, num2=~) // (or some other special character)