How to use the command 'dune' (with examples)
Dune is a build system for OCaml programs. It provides a simple and efficient way to build, test, and clean up your OCaml projects.
Use case 1: Build all targets
Code:
dune build
Motivation:
Building all targets is necessary when you want to compile your OCaml program and generate executable files or libraries. It ensures that all the necessary files are generated for your project.
Explanation:
dune: The command to execute Dune.build: The subcommand to build all targets specified in the Dune file.
Example output:
Info: creating file dune-project.shadow (was dune-project)
File "src/my_module.ml", line 3, characters 2-13:
Warning 32: unused open Loop.
File "src/my_module.ml", line 4, characters 2-13:
Warning 32: unused open Test.
Use case 2: Clean up the workspace
Code:
dune clean
Motivation:
Cleaning up the workspace is useful when you want to remove all generated files and clean the project directory. It helps you start with a clean slate.
Explanation:
dune: The command to execute Dune.clean: The subcommand to clean the workspace.
Example output:
Info: cleaning
Done cleaning
Use case 3: Run all tests
Code:
dune runtest
Motivation:
Running all tests is essential to ensure the correctness of your OCaml program. It executes all the test cases defined in the project and provides feedback on their success or failure.
Explanation:
dune: The command to execute Dune.runtest: The subcommand to run all tests.
Example output:
Info: dune will run the following tests:
my_module_test
File "test/my_module_test.ml", line 5, characters 12-26:
Error: Assertion failed
Use case 4: Start the utop REPL with compiled modules automatically loaded into it
Code:
dune utop
Motivation:
Starting the utop REPL with compiled modules loaded automatically saves time and effort in loading the necessary modules manually. It provides an interactive environment to explore and experiment with your OCaml code.
Explanation:
dune: The command to execute Dune.utop: The subcommand to start utop REPL with compiled modules.
Example output:
┌─────┐┌───┐┌─┐
│ ┌──┘│ │ │ │
│ │ │ │ │ │
│ │ │ │ │ │
│ └───┘└─┘─┘─┘
utop # let x = 42;;
val x : int = 42
Conclusion:
Dune is a powerful build system for OCaml programs that simplifies the building, testing, and cleaning processes. By understanding and using the various subcommands provided by Dune, you can efficiently manage your OCaml projects.
