FromFile.jl

This package exports a macro @from, which can be used to import objects from files.

The hope is that you will never have to write include again.

Installation

FromFile is a Julia Language package. To install FromFile, please open Julia's interactive session (known as REPL) and press ] key in the REPL to use the package mode, then type the following command

pkg> add FromFile

Usage

Objects in other files may be imported in the following way:

# file1.jl
import FromFile: @from
@from "file2.jl" import foo

bar() = foo()

#file2.jl
foo() = println("hi")

File systems may be navigated: @from "../folder/file.jl" import foo, whereby the @from macro will safely translate system specific path formulations by calling abspath() under the hood.

The usual import syntax is supported; the only difference is that the objects are looked up in the file requested: @from "file.jl" using MyModule; @from "file.jl" import MyModule: foo; @from "file.jl" import foo, bar.

Using @from to access a file multiple times (for example calling @from "file.jl" import foo in multiple files) will access the same objects each time; i.e. without the duplication issues that include("file.jl") would introduce.

Specification

FromFile.jl is a draft implementation of this specification, for improving import systems as discussed in Issue 4600.

Tips

FromFile will (besides its programmatic benefits like the removal of spooky action at a distance) help you keep track of what objects are defined in what file. When converting over to FromFile that may mean untangling your existing project, and figuring out exactly what you defined where. To print out which file defines which object, you can execute the following bash snippet at the root of your project:

for f in $(find . -name '*.jl'); do echo $f && cat $f | vim - -nes -c '%s/#.*//ge' -c '%s/"""\_.\{-}"""//ge' -c '%v/^\S\+/d_' -c '%g/^\(end\|@from\|using\|export\|import\|include\|begin\|let\)\>/d_' -c '%g/.*/exe "norm >>"' -c ':%p' -c ':q!' | tail -n +2; done | less

This should (hopefully) print out each file, and the objects defined in that file. It's not perfect, but it'll help you get 90% of the way there.