Melange

2.0.1

2.0.1

Update to OCaml

v1.4.0

Version 1.4.0

Add Lens.effect

One often has the need to do side-effecty stuff, doing something like
map >> ignore. The effect function is here to make that pattern
easier to deal with

Add Windows Support

v1.2.7

Add Windows Support

Update PPXLib version

This release updates the PPXLib version so it can be compiled with latest ocaml

Add License (BSD 3-clause)

v1.2.2

Release version v1.2.2

Fix Stackoverflow

As it turns out this got compiled to a while loop in Bucklescript,

  let rec findBy = fn =>
    fun
    | [] => None
    | [x, ..._] when fn(x) => Some(x)
    | [_, ...xs] => findBy(fn, xs);

But this didn't.

  let rec replaceBy = (e, fn) =>
    fun
    | [] => []
    | [x, ...xs] when fn(x) => [e, ...xs]
    | [x, ...xs] => [x, ...replaceBy(e, fn, xs)];

In the Array version we simply map as slicing the array is O(n) anyway. For the linked list, I figured we could be more clever and simple join the rest of the list back onto itself when we've found the element. There were some attempts at cleverness, using an accumulator, but those ended up just being slower, as the accumulator would have to append to keep the list ordered, which is slow. Prepending and then reversing the list is another O(n) operation, meaning in the worst case scenario we would run 0(n*2).

This is now just a map.

FindBy / FindByLens for Array / List

This release adds a lens for finding elements in an Array or List.

Either directly, if you can provide the full item to find

Lens.set(
  Lens.List.find(5) >>- Lens.Option.orExn,
  200,
  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
)
|> expect
|> toEqual([0, 1, 2, 3, 4, 200, 6, 7, 8, 9, 10])

Or by providing an additional lens to find something by a record.

[@pancake]
type user = {
  id: int,
  username: string,
};
let users = [
  {id: 0, username: "0"},
  {id: 1, username: "1"},
  {id: 2, username: "2"},
  {id: 3, username: "3"},
];

Lens.view(Lens.List.findByLens(0, userIdLens), users)
|> expect
|> toEqual(Some({id: 0, username: "0"}))

Checkout the tests for lists, arrays, or this arbitrarily complicated nested thing to see some more examples (and how they compose into Lens.Option to add fallback values, or throw exceptions when they're not found

v1.1.0 -- List / Array / Option / Result / Tests

We now support some extra helpers;

List & Array

• Lens.List.atOrElse
• Lens.Array.atOrElse

Takes an integer, and a default. When viewing, it will try to view the element. If it's out of bounds, it will return the default. When setting, it will set the element if it's in bounds, and return the original array if it's out of bounds. You can supply negative integers to wrap around (ie. -1 is the last element)

• Lens.List.atOrExn
• Lens.Array.atOrExn
  Same as atOrElse, but will throw when out of bounds

Option & Result

• Lens.Option.orElse

• Lens.Result.orElse
  These will take a default value, when it is either None or Error(...), they will return the default when viewing. Setting will always be wrapped in either Some(...) or Ok(...).

• Lens.Option.orExn

• Lens.Result.orExn
  Same as orElse, but will throw when out of bounds

We've also made sure these are covered by tests properly...

v1.0.5

This release uses the pre-build variant, as build by CI