locally defined functions that call themselves

[clarkfitzg]

If a function is defined locally and calls itself (so it's recursive), then ideally CodeDepends should identify that the usage of the function is local, and not from a package. This came up for me in tryCatch, specifically getInputs(tryCatch)[[3L]] where tryCatchList defines and uses itself. One can use Recall to achieve the same result.

Here's a minimal example:

add_123 = function(x){
    add = function(y, ...){
        if(!missing(y)){
            y + add(...)
            #y + Recall(...)  # Alternatively
        } else 0
    }
    add(x, 1, 2, 3)
}

info = getInputs(add_123)

info[[3]]@functions["add"]  # FALSE, should be TRUE

info[[4]]@functions["add"]  # TRUE, as expected

I can work around this behavior by checking if the name of the function used is also an output.

The documentation for the functions slot from getInputs states:

Note that this is not recursive.

I understand this to mean that it doesn't recursively look at all functions called.

[duncantl]

For the straightforward cases, we can add that. I just didn't look for function definitions explicitly.
Not certain yet where I want to do this without giving it a little thought, i.e. in CodeAnalysis or in CodeDepends. I'll try to find time to rationalize the separation and role of each of these in the next few weeks.

[clarkfitzg]

There's also a related issue with TryCatch. That is, tryCatchList uses tryCatchOne that's only defined later in the body. I'm mentioning it here so we don't forget.