Created
August 9, 2024 05:08
-
-
Save memotype/92d0dcdbdf0c002a41e8c49f05bde7ea to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
In OCaml, it is conventional for modules to define functions that return a new value of the module's main type using a variety of naming patterns, depending on the context and the specific purpose of the function. The most common naming patterns are: | |
1. **`make`**: This is the most common and general naming convention for functions that construct new values of a type. For example: | |
- `Array.make` creates a new array with a specified size and initializes all elements to a given value. | |
- `List.make` could theoretically be used to create a list with a given size and default value (though OCaml's standard `List` module doesn't provide this). | |
The `make` function usually indicates that the function will create a new instance of the type, often taking parameters to initialize it. | |
2. **`create`**: Similar to `make`, but often used when the function is more complex, perhaps involving more parameters or more intricate initialization logic. For example: | |
- `Hashtbl.create` initializes a new hash table with a specified initial size. | |
- `Buffer.create` initializes a new buffer with a specified initial size. | |
The `create` function often implies that there might be some setup involved, beyond just setting a size or value. | |
3. **Specialized Creation Functions**: Sometimes, a module might provide specialized creation functions tailored to specific use cases. For example: | |
- `Array.create_float` is a specialized function that creates an array optimized for storing floats, as floats in OCaml have special memory considerations. | |
- A module might offer functions like `create_with_capacity` or `create_from_list` to clarify the specific intent or optimization. | |
4. **`init`**: This is another common convention, especially when the creation process involves generating elements or initializing them based on a function or some form of iteration. For example: | |
- `Array.init` creates an array and initializes its elements using a function. | |
- `List.init` (if implemented) would similarly create a list with elements generated by a function. | |
5. **Anonymous Struct Creation**: For record types and other more complex structures, it is common to define values directly rather than through a function. However, in more abstract modules where you don't want to expose the underlying structure, a `make`, `create`, or other function would be used to abstract away the construction details. | |
### Best Practices | |
- **Use `make` for simplicity**: If the creation of the type is straightforward, with no complex initialization required, `make` is usually preferred. | |
- **Use `create` for more complex or customizable construction**: If you expect users to need more flexibility or when the creation process is not trivial, use `create`. | |
- **Provide specialized functions when needed**: If there's a clear need for different types of creation methods, provide them with clear and descriptive names. | |
- **Leverage `init` when initializing with a function**: When generating elements based on a function or a computation, `init` is a common choice. | |
### Example | |
If you were defining a simple stack module, you might have: | |
```ocaml | |
module Stack = struct | |
type 'a t = { mutable elements : 'a list } | |
let make () = { elements = [] } | |
let push x s = s.elements <- x :: s.elements | |
let pop s = match s.elements with | |
| [] -> None | |
| x :: xs -> s.elements <- xs; Some x | |
end | |
``` | |
Here, `make` is used for a straightforward, empty stack creation. If you had a more complex stack that required some setup (like a pre-populated stack or one with a specific size), you might use `create` instead. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment