Could you please elaborate a bit how import solves the problem?
To give a simple example of what I meant by source files being non-self-contained:
Suppose I’m reading source of CSV.jl and come across this line (https://github.com/JuliaData/CSV.jl/blob/04a2cc7caa7eff226d8dadeae7d63d8d9867a19b/src/detection.jl#L191):
makeunique([normalizenames ? normalizename(x) : Symbol(x) for x in names]).
Oh, I need something like this in my project, completely independent of CSV! OK, but where do these functions makeunique and normalizename come from? There are no imports in this file at all - so I don’t even know if these functions are in CSV.jl or some other package it depends on. One needs to use github search and hope that it points to the definition of these functions, if they are in CSV.jl at all. If they are in another package it’s even more complicated.
Contrast this to each file being a separate “module-like” entity, with imports at the top - something like:
using Parsers
using PooledArrays
using .utils
# code
Easy to guess that those two functions do not live in Parser or PooledArrays, even if imported names are not listed explicitly. Then no search is required: they are contained in utils.jl.