Embed Directive in Julia

Here’s the translation of the Go embed directive example to Julia:

In Julia, we don’t have an exact equivalent of Go’s embed directive. However, we can achieve similar functionality using Julia’s built-in features and packages. We’ll use the Base.read function to read file contents and the Pkg.Dir module to handle relative paths.

using Pkg.Dir

# Read the contents of a single file into a string
file_string = read(joinpath(@__DIR__, "folder", "single_file.txt"), String)

# Read the contents of a single file into a byte array
file_byte = read(joinpath(@__DIR__, "folder", "single_file.txt"))

# Function to read multiple files from a folder
function read_folder(folder_path, pattern)
    files = Dict{String, Vector{UInt8}}()
    for file in readdir(folder_path)
        if occursin(pattern, file)
            file_path = joinpath(folder_path, file)
            files[file] = read(file_path)
        end
    end
    return files
end

# Read multiple files from a folder
folder_path = joinpath(@__DIR__, "folder")
folder = read_folder(folder_path, r"\.hash$")

function main()
    # Print out the contents of single_file.txt
    print(file_string)
    print(String(file_byte))

    # Retrieve some files from the folder
    content1 = String(get(folder, "file1.hash", UInt8[]))
    print(content1)

    content2 = String(get(folder, "file2.hash", UInt8[]))
    print(content2)
end

main()

To run this example, you need to set up the folder structure and files as follows:

$ mkdir -p folder
$ echo "hello julia" > folder/single_file.txt
$ echo "123" > folder/file1.hash
$ echo "456" > folder/file2.hash

Then, you can run the Julia script:

$ julia embed_example.jl
hello julia
hello julia
123
456

In this Julia version:

1. We use read function to read file contents into a string or byte array.
2. We define a read_folder function to simulate the behavior of embedding multiple files. This function reads all files matching a given pattern in a folder.
3. We use joinpath and @__DIR__ to construct file paths relative to the script’s directory, similar to Go’s relative path handling in embed directives.
4. The main function demonstrates how to use the read file contents, similar to the Go example.

Note that this approach reads the files at runtime, unlike Go’s embed directive which embeds the files at compile time. For a more robust solution in larger projects, you might want to consider using a package like Artifacts.jl for managing external files and resources.