Julia code loading

The documentation about Julia code loading: https://docs.julialang.org/en/v1/manual/code-loading/

See also Julia package management

Package loading

main.jl has access to the JuliaHello module because Julia sees src/JuliaHello.jl as an entry point for the JuliaHello package / module.

## src/JuliaHello.jl
module JuliaHello
greet() = print("Hello World!")
end # module

## main.jl
using JuliaHello
JuliaHello.greet()

“Developing” a temporary package

Use the Julia Pkg command dev --local pkg...

Julia docs | Pkg | dev

Assuming we have the file structure for the packages

. present working directory (pwd)
| - main.jl
| - Manifest.toml
| - Project.toml
|
+---Mod1.jl
|   | - Manifest.toml (optional)
|   | - Project.toml
|   |
|   \---src
|         - Mod1.jl
|
\---Mod2.jl
    | - Manifest.toml (optional)
    | - Project.toml
    |
    \---src
          - Mod2.jl

Add local packages and track the file changes in the Julia REPL

julia> ]
pkg> activate .
pkg> dev --local Mod1 Mod2

Or run the commands in the Julia script

import Pkg

# To generate Project.toml if not present
Pkg.activate(".")

Pkg.develop(PackageSpec(path="Mod1.jl"))
Pkg.develop(PackageSpec(path="Mod2.jl"))

• Best when Mod1 and Mod2 are modified frequently and shared.
• Loaded code is determined by local files instead of package versions.
• The updates are loaded when using is invoked, along with precompilation. Revise.jl tracks and updates modified files and you don’t have to restart the Julia process upon module code changes.