The challenges of documenting generic functions

[adienes]

@goerz

has to be somewhat vague: The person introducing findall has absolutely no control over the methods of findall that someone else might implement, and what their arguments might be

I tend to find it very helpful when functions are documented in terms of consistency with other existing methods. e.g. findall(x) might be documented to return the same thing as collect(i for (i,v) in enumerate(x) if v)