# Base v0.11 released, with breaking changes

**URL:** <https://discuss.ocaml.org/t/base-v0-11-released-with-breaking-changes/1766>\
**Category:** Community\
**Tags:** base\
**Created:** [March 23, 2018, 4:36pm UTC](https://discuss.ocaml.org/t/base-v0-11-released-with-breaking-changes/1766 "2018-03-23T16:36:37Z")\
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**Author:** ![Yaron\_Minsky](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/yaron_minsky/32/11_2.png) [@Yaron\_Minsky](https://discuss.ocaml.org/u/Yaron_Minsky)\
**Post date:** [March 23, 2018, 4:36pm UTC](https://discuss.ocaml.org/t/base-v0-11-released-with-breaking-changes/1766/1 "2018-03-23T16:36:37Z")

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We just put out a new release of Base, version v0.11, and it is available in opam now. (Along with the rest of Jane Street’s open source libraries, which have all been released, with the same version number.)

Base hasn’t yet reached it’s 1.0 release, but we hope to get there in the next six months. One of our reasons for delaying the 1.0 release is that we intend for the 1.0 release to prioritize stability of the APIs, and there are a few changes that we need to make before then. You can see some of the remaining changes we want to make before declaring 1.0 on our Roadmap.

As of our 0.11 release, we’ve hit a majority of the issues on our roadmap, but there are still a few to go. But if stability is your top priority, you might want to wait for 1.0 before adopting Base.

You can find the Base changelog on [GitHub](https://github.com/janestreet/base/blob/master/CHANGES.md), but here’s a version below, highlighting some of the breaking changes.

# v0.11

## Breaking Changes

- Make `~compare` a required argument to `List.dedup_and_sort`, `List.dedup`, `List.find_a_dup`, `List.contains_dup`, and `List.find_all_dups`.

- Deprecated `Not_found`, people who need it can use `Caml.Not_found`, but its use isn’t recommended.

- Removed unnecessary unit argument from `Hashtbl.create`.

- Removed `Hashable.t` constructors from `Hashtbl` and `Hash_set`, instead favoring the first-class module constructors.

- Removed `Container` operations from `Either.First` and `Either.Second`.

- Changed the type of `fold_until` in the `Container` interfaces. Rather than returning a `Finished_or_stopped_early.t` (which has also been removed), the function now takes a `finish` function that will be applied the result if `f` never returned a `Stop _`.

- Removed the `String_dict` module.

- Removed `List.exn_if_dup`. It is still available in core\_kernel.

- Removed “normalized” index operation `List.slice`. It is still available in core\_kernel.

- Remove “normalized” index operations from `Array`, which incluced `Array.normalize`, `Array.slice`, `Array.nget` and `Array.nset`. These operations are still available in core\_kernel.

- Remove “normalized” index operations from `String`, which incluced `String.normalize`, `String.slice`, `String.nget` and `String.nset`. These operations are still available in core\_kernel.

- Removed approximate float comparison operations, e.g., `(<=.)`

## Removal of deprecated functionality

- Removed deprecated operations from `Hashtbl`.

## Deprecations

- Deprecated `all_ignore` in the `Monad` and `Applicative` interfaces in favor of `all_unit`.

- Deprecated `Array.replace_all` in favor of `Array.map_inplace`, which is the standard name for that sort of operation within Base.

## Documentation changes

- Document that `Array.find_exn`, `Array.find_map_exn`, and `Array.findi_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

- Document that `List.find_exn`, and `List.find_map_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

- Document that `List.find_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

- Document that `String.lsplit2_exn`, and `String.rsplit2_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

- Document that `List.find_exn`, and `List.find_map_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

## Other enhancements

- Added `Sequence.group`, similar to `List.group`.

- Reimplemented `String.Caseless.compare` so that it does not allocate.

- Added the `Sexp.Not_found_s` exception which will replace `Caml.Not_found` as the default exception in a future release.

- Added `Sys.argv`.

- Added a infix exponentation operator for int.

- Added a `Formatter` module to reexport the `Format.formatter` type and updated the deprecation message for `Format`.

- Added `Sys.backend_type`.

- Added `String.is_substring_at string ~pos ~substring`. Used it as back-end for `is_suffix` and `is_prefix`.

- Added `Uniform_array` module that is just like an `Array` except guarantees that the representation array is not tagged with `Double_array_tag`, the tag for float arrays.

- Added `Option_array` module that allows for a compact representation of `'a option array`, which avoids allocating heap objects representing `Some a`.

- Moved all remaining `Replace_polymorphic_compare` submodules from Base types and consolidated them in one place within `Import0`.

- Document that `Hashtbl.find_exn` may throw `Caml.Not_found` _or_ `Not_found_s`.

- Added a `Poly` submodule to `Map` and `Set` that exposes constructors that use polymorphic compare.

- Added a `Queue` module that is backed by an `Option_array` for efficient and (non-allocating) implementations of most operations.

- Added missing conversions between `Int63` and other integer types, specifically, the versions that return options.

- Added truncating versions of integer conversions, with a suffix of `_trunc`. These allow fast conversions via bit arithmetic without any conditional failure; excess bits beyond the width of the output type are simply dropped.

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_[View the full topic](https://discuss.ocaml.org/t/base-v0-11-released-with-breaking-changes/1766)._