Embed Directive in OCaml

Here’s the translation of the Go code to OCaml, with explanations in Markdown format suitable for Hugo:

Our example demonstrates the use of external files in OCaml programs. While OCaml doesn’t have a direct equivalent to the embed directive, we can achieve similar functionality using the standard library’s file handling capabilities.

(* We'll use the Sys and In_channel modules for file operations *)
open Sys
open In_channel

(* Function to read the contents of a file *)
let read_file filename =
  let channel = open_in filename in
  let contents = input_all channel in
  close_in channel;
  contents

(* Main function *)
let () =
  (* Read and print the contents of single_file.txt *)
  let file_string = read_file "folder/single_file.txt" in
  print_string file_string;

  (* Read and print the contents of file1.hash *)
  let content1 = read_file "folder/file1.hash" in
  print_string content1;

  (* Read and print the contents of file2.hash *)
  let content2 = read_file "folder/file2.hash" in
  print_string content2

In this OCaml version, we’ve created a read_file function that reads the entire contents of a file into a string. This function is then used in the main part of the program to read and print the contents of various files.

To run this example, you’ll need to create the necessary files and folders first:

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

Then, you can compile and run the OCaml program:

$ ocamlc -o embed_files embed_files.ml
$ ./embed_files
hello ocaml
123
456

Note that unlike the original example, which embeds the files at compile time, this OCaml version reads the files at runtime. If you need to bundle the files with your executable, you would typically use a build system or packaging tool to include the necessary files alongside your compiled program.

OCaml doesn’t have a built-in way to embed files directly into the executable like Go’s embed directive. However, for more complex scenarios, you might consider using a library like dune (a popular build system for OCaml) which provides features for managing and including external resources in your projects.