> This is a **major release** that **may** involve some **breaking API changes** in rare cases for users of some low-level or obscure features that have been made private or removed. If your code compiles with this new version of Nippy, you should be fine.
> As with all Nippy releases: this version can read data written by older versions but older versions may not be able to read data written by _this_ version.
> No changes since `2.12.0-RC2`
> Changes since `2.11.1`:
* **BREAKING**: dropped support for `*final-freeze-fallback*` (rarely used)
* **BREAKING**: dropped support for `*default-freeze-compressor-selector*` (rarely used)
* **BREAKING**: made several implementation details private, incl. most low-level `write-<x>` and `read-<x>` fns (rarely used)
* **Performance**: several significant speed + space efficiency improvements, including more variable-sized types
* **New built-in types** (these previously fell back to the reader): regex patterns, symbols
* **New experimental caching feature** (please see `cache` docstring for details)
* **New**: `fast-freeze`, `fast-thaw` utils (please see docstrings for details)
* **Change**: `freeze` return val is no longer auto type hinted as `^bytes` (had a performance cost, rarely used)
* **Hotfix**: `fn?`s were incorrectly reporting true for `serializable?`
* **Hotfix**: *final-freeze-fallback* back compatibility was broken
> This is a **major release** that **may** involve some **breaking API changes** in rare cases for users of some low-level or obscure features that have been made private or removed. If your code compiles with this new version of Nippy, you should be fine.
> As with all Nippy releases: this version can read data written by older versions but older versions may not be able to read data written by _this_ version.
**PLEASE REPORT ANY PROBLEMS**, thank you!
-@ptaoussanis
> No changes since `2.12.0-beta3`.
> Changes since `2.11.1`:
* **BREAKING**: dropped support for `*final-freeze-fallback*` (rarely used)
* **BREAKING**: dropped support for `*default-freeze-compressor-selector*` (rarely used)
* **BREAKING**: made several implementation details private, incl. most low-level `write-<x>` and `read-<x>` fns (rarely used)
* **Performance**: several significant speed + space efficiency improvements, including more variable-sized types
* **New built-in types** (these previously fell back to the reader): regex patterns, symbols
* **New experimental caching feature** (please see `cache` docstring for details)
* **New**: `fast-freeze`, `fast-thaw` utils (please see docstrings for details)
* **Change**: `freeze` return val is no longer auto type hinted as `^bytes` (had a performance cost, rarely used)
* **Hotfix**: `fn?`s were incorrectly reporting true for `serializable?`
* **Hotfix**: *final-freeze-fallback* back compatibility was broken
> This is a **major release** that **may** involve some **breaking API changes** in rare cases for users of some low-level or obscure features that have been made private or removed. If your code compiles with this new version of Nippy, you should be fine.
> As with all Nippy releases: this version can read data written by older versions but older versions may not be able to read data written by _this_ version.
* **BREAKING**: dropped support for `*final-freeze-fallback*` (rarely used)
* **BREAKING**: dropped support for `*default-freeze-compressor-selector*` (rarely used)
* **BREAKING**: made several implementation details private, incl. most low-level `write-<x>` and `read-<x>` fns (rarely used)
* **Performance**: several significant speed + space efficiency improvements, including more variable-sized types
* **New built-in types** (these previously fell back to the reader): regex patterns, symbols
* **New experimental caching feature** (please see `cache` docstring for details)
* **New**: `fast-freeze`, `fast-thaw` utils (please see docstrings for details)
* **Change**: `freeze` return val is no longer auto type hinted as `^bytes` (had a performance cost, rarely used)
> This is a major **non-breaking** release that improves performance and makes thawing more resilient to certain failures. Identical to **v2.9.0-RC3**.
* **Performance**: eliminate some unnecessary boxed math
* **New**: allow intelligent auto-selection of `freeze` compression scheme using `:auto` compressor (now the default). This can result in significant speed+space improvements for users serializing many small values.
> **Major release** with significant performance improvements, a new default compression type ([LZ4](http://blog.jpountz.net/post/28092106032/wow-lz4-is-fast)), and better support for a variety of compression/encryption tools.
>
> The data format is fully **backwards-compatible**, the API is backwards compatible **unless** you are using the `:headerless-meta` thaw option.
### Changes
* A number of internal performance improvements.
* Added [LZ4](http://blog.jpountz.net/post/28092106032/wow-lz4-is-fast) compressor, **replacing Snappy as the default** (often ~10+% faster with similar compression ratios). **Thanks to [mpenet](https://github.com/mpenet) for his work on this**!
* **BREAKING**: the `thaw``:headerless-meta` option has been dropped. Its purpose was to provide Nippy v1 compatibility, which is now done automatically. To prevent any surprises, `thaw` calls with this option will now **throw an assertion error**.
* **IMPORTANT**: the `thaw` API has been improved (simplified). The default `:encryptor` and `:compressor` values are now both `:auto`, which'll choose intelligently based on data now included with the Nippy header. Behaviour remains the same for data written without a header: you must specify the correct `:compressor` and `:encryptor` values manually.
