Embed Directive in F#
Here’s the translation of the Go code example to F#, along with explanations in Markdown format suitable for Hugo:
F# doesn’t have a direct equivalent to the embed
directive, but we can achieve similar functionality using EmbeddedResource
in F#/.NET. Here’s how we can approach this:
open System.Reflection
open System.IO
// Define a type to hold our embedded resources
type EmbeddedFiles = class end
// Read the contents of an embedded resource as a string
let readEmbeddedResourceAsString (resourceName: string) =
let assembly = Assembly.GetExecutingAssembly()
use stream = assembly.GetManifestResourceStream(resourceName)
use reader = new StreamReader(stream)
reader.ReadToEnd()
// Read the contents of an embedded resource as bytes
let readEmbeddedResourceAsBytes (resourceName: string) =
let assembly = Assembly.GetExecutingAssembly()
use stream = assembly.GetManifestResourceStream(resourceName)
use memoryStream = new MemoryStream()
stream.CopyTo(memoryStream)
memoryStream.ToArray()
[<EntryPoint>]
let main argv =
// Print out the contents of 'single_file.txt'
let fileString = readEmbeddedResourceAsString "EmbeddedFiles.folder.single_file.txt"
printfn "%s" fileString
let fileByte = readEmbeddedResourceAsBytes "EmbeddedFiles.folder.single_file.txt"
printfn "%s" (System.Text.Encoding.UTF8.GetString(fileByte))
// Retrieve some files from the embedded folder
let content1 = readEmbeddedResourceAsString "EmbeddedFiles.folder.file1.hash"
printfn "%s" content1
let content2 = readEmbeddedResourceAsString "EmbeddedFiles.folder.file2.hash"
printfn "%s" content2
0 // return an integer exit code
To use this code, you need to add your files as embedded resources in your F# project. In Visual Studio, you can do this by:
- Right-clicking on the file in Solution Explorer
- Selecting “Properties”
- Setting “Build Action” to “Embedded Resource”
Alternatively, if you’re using a .fsproj file directly, you can add the following lines:
<ItemGroup>
<EmbeddedResource Include="folder\single_file.txt" />
<EmbeddedResource Include="folder\file1.hash" />
<EmbeddedResource Include="folder\file2.hash" />
</ItemGroup>
Now, let’s break down the code:
We define a type
EmbeddedFiles
to serve as a namespace for our embedded resources.We create two helper functions:
readEmbeddedResourceAsString
: Reads an embedded resource as a string.readEmbeddedResourceAsBytes
: Reads an embedded resource as a byte array.
In the
main
function:- We read and print the contents of
single_file.txt
as both a string and a byte array. - We read and print the contents of
file1.hash
andfile2.hash
.
- We read and print the contents of
To run this example:
- Create a folder named “folder” in your project directory.
- Create the following files with the specified content:
folder/single_file.txt
: “hello f#”folder/file1.hash
: “123”folder/file2.hash
: “456”
- Add these files as embedded resources to your project.
- Compile and run the program.
The output should be:
hello f#
hello f#
123
456
This approach provides similar functionality to the embed directive in F#, allowing you to include file contents in your compiled assembly and access them at runtime.