Conventions around storage var naming and use

[milancermak]

I think we should come up with a convention for naming and use of @storage_vars.

Here's an example what I've been using most recently:

@storage_var
func treasury() -> (address : felt):
end

@constructor
func constructor(treasury_ : felt):
    treasury.write(treasury_)
    return ()
end

@view
func get_treasury() -> (treasury : felt):
    let (treasury_) = treasury.read()
    return (treasury_)
end

@external
func set_treasury(treasury : felt):
    treasury.write(treasury_)
    return ()
end

That is, using a trailing underscore for the variable name inside a function (or as a argument passed into it) that holds the value of a @storage_var of the same name. But I don't really like it that much.

What I've seen in the code of others:

1. using leading underscore for variable name: let (_treasury) = treasury.read()
2. using trailing underscore for @storage_var name: let (treasury) = treasury_.read()
3. using _storage appended to the name: let (treasury) = treasury_storage.read()

Is there any you like? Can you think of any other that you'd like us to adopt?

[milancermak]

@nuts-rice @bllu404

[milancermak]

Check out this discussion

It turns out that in Cairo, when importing from two files that hold a @storage_var of the same name, the one that's imported later will silently overshadow the former one. This is not good ⚠️

We ought to take that into account when coming up with a convention.

[nuts-rice]

I like the leading underscore myself amd have been using that

[milancermak]

I'm starting to dislike the trailing underscore because it can be confusing with a ignored var, like in let (q, _) = unsigned_div_rem(a, b) - here, q_ and q, _ are too similar.

[nuts-rice]

I figure leading underscores would be best as well as _storage until there's clear syntactic conventions around types passed in as parameters.