backprop-0.2.4.0: CHANGELOG.md
Changelog
=========
Version 0.2.4.0
---------------
*May 28, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.2.4.0>
**NOTE** Major breaking changes to *Explicit* modules, and some re-shuffling of
typeclass constraints on various non-explicit functions that should only affect
polymorphic usage.
* *Huge improvements in performance!* Around 20-40% reduction in
runtimes/overheads, with savings higher for large matrix situations or
situations with expensive `add`.
* However, this restructuring required *major* reshuffling of constraints on
`Backprop`/`Num` for most functions. These are potentially **breaking
changes** for polymorphic code, but monomorphic code should remain
unchanged. However, code using the *Explicit* interfaces is most likely
broken unfortunately. Fixes just include adding or dropping `zeroFunc`s to
the appropriate functions.
* Added warnings to *Explicit* modules that the API is "semi-stable".
* `overVar` and `%~~`, for modifying fields. Essentially a wrapper over a
`viewVar` and `setVar`.
* Argument order in the `backpropWith` family of functions changed again;
**breaking change** for those using any `backpropWith` function. However,
the new order is much more usable.
* Changes to the argument order in the `backprop` family of functions in the
*Explicit* interfaces now reverted back to previous order, from v0.2.0 and
before. Should be an "un-breaking" change, but will break code written in
v0.2.3 style.
* Bechmarks now include HKD access and a "hybrid" approach. Documentation
updated to reflect results.
* Documentation updated to include a new "unital" law for `one`, namely `one
= gradBP id`.
* Fixity declarations for `^^?`, `^^?!`, and `<$>`.
* Added `fmap . const` and `<$` to *Prelude* modules.
* `Backprop` instances for `Expr` from *simple-reflect*
* Added `zeroVecNum` and `oneVecNum` to *Numeric.Backprop.Class*, which is
potentially more efficient than `zeroVec` and `oneVec` if the items are
instances of `Num` and the vectors are larger. Also added `NumVec` newtype
wrapper giving `Backprop` instances to vectors using `zeroVecNum` and
`oneVecNum` instead of `zeroVec` and `oneVec`.
* `Build.hs` build script now also builds profiling results
Version 0.2.3.0
---------------
*May 25, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.2.3.0>
* Argument order in `backpropWith` family of functions switched around to
allow for final gradient to be given after-the-fact. **Breaking change**
for anyone using any `backpropWith` function.
* As a consequence of the previous change, `backprop` family of functions in
*Explicit* interfaces also all changed argument order. **Breaking change**
only for those using the *Explicit* interfaces.
* Explicit `collectVar` no longer needs a `ZeroFunc` for the container, and
so all versions of `collectVar` and functions that use it (`fmap`,
`liftA2`, `liftA3`, `traverse`, `mapAccumL`, `mapAccumR`) no longer require
`Backprop` or `Num` instances for the final returned container type. This
enables a lot more flexibility in container types. **Breaking change**
only for those using the *Explicit* interfaces.
* `BV` pattern synonym added to *Numeric.Backprop*, abstracting over
application of `splitBV` and `joinBV`.
* `foldr` and `foldl'` added to Prelude modules, for convenience.
* `round` and `fromIntegral'` ("unround") added to Prelude modules.
Version 0.2.2.0
---------------
*May 12, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.2.2.0>
* `evalBP0` added, for convenience for no-argument values that need to be
evaluated without backpropagation.
* `splitBV` and `joinBV` for "higher-kinded data" style `BVar` manipulation,
via the `BVGroup` helper typeclass.
* `toList`, `mapAccumL`, and `mapAccumR` for *Prelude.Backprop* modules
* `Backprop` instance for `BVar`
* *COMPLETE* pragmas for `T2` and `T3`
* Un-exported `gzero`, `gadd`, and `gone` from *Numeric.Backprop.Class*
* Many, many more instances of `Backprop`
* `Backprop` instance for `Proxy` made non-strict for `add`
* Swapped type variable order for a few library functions, which might
potentially be breaking changes.
*Internal*
* Fixed documentation for Num and Explicit Prelude modules, and rewrote
normal and Num Prelude modules in terms of canonical Prelude definitions
* Switched to `errorWithoutStackTrace` wherever appropriate (in *Internal*
module)
Version 0.2.1.0
---------------
*May 8, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.2.1.0>
* Added `ABP` newtype wrapper to *Numeric.Backprop.Class* (re-exported from
*Numeric.Backprop* and *Numeric.Backprop.Explicit*) to give free `Backprop`
instances for Applicative actions.
* Added `NumBP` newtype wrapper to *Numeric.Backprop.Class* (re-exported in
the same places as `ABP`) to give free `Backprop` instances for `Num`
instances.
* Added `^^?!` (unsafe access) to *Numeric.Backprop* and
*Numeric.Backprop.Num*.
* `Backprop` instance for `Natural` from *Numeric.Natural*. Should actually
be safe, unlike its `Num` instance!
* `zfFunctor` and `ofFunctor` for instances of `Functor` for
*Numeric.Backprop.Explicit*.
* `realToFrac` and `fromIntegral` to *Prelude* modules
* `T2` and `T3` patterns for *Numeric.Backprop*, for conveniently
constructing and deconstructing tuples.
Version 0.2.0.0
---------------
*May 1, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.2.0.0>
* Added `Backprop` class in *Numeric.Backprop.Class*, which is a typeclass
specifically for "backpropagatable" values. This will replace `Num`.
* API of *Numeric.Backprop* completely re-written to require values be
instances of `Backprop` instead of `Num`. This closes some outstanding
issues with the reliance of `Num`, and allows backpropagation to work with
non-Num instances like variable-length vectors, matrices, lists, tuples,
etc. (including types from *accelerate*)
* *Numeric.Backprop.Num* and *Prelude.Backprop.Num* modules added, providing
the old interface that uses `Num` instances instead of `Backprop`
instances, for those who wish to avoid writing orphan instances when
working with external types.
* *Numeric.Backprop.Explicit* and *Prelude.Backprop.Explicit* modules added,
providing an interface that allows users to manually specify how zeroing,
addition, and one-ing works on a per-value basis. Useful for those who
wish to avoid writing orphan instances of `Backprop` for types with no
`Num` instances, or if you are mixing and matching styles.
* `backpropWith` variants added, allowing you to specify a "final gradient",
instead of assuming it to be 1.
* Added `auto`, a shorter alias for `constVar` inspired by the *ad* library.
* *Numeric.Backprop.Tuple* module removed. I couldn't find a significant
reason to keep it now that `Num` is no longer required for backpropagation.
Version 0.1.5.2
---------------
*Apr 26, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.5.2>
* Added `coerceVar` to *Numeric.Backprop*
* Added `Random` instaces for all tuple types. Same as for `Binary`, this
does incur a *random* and *time* dependency only from the tuple types.
Again, because these packages are a part of GHC's boot libraries, this
is hopefully not too bad.
Version 0.1.5.1
---------------
*Apr 9, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.5.1>
* Fixed `NFData` instance for `T`; before, was shallow.
* Added `Typeable` instances for all tuple types, and for `BVar`.
* Added `Eq`, `Ord`, `Show`, etc. instances for `T`.
* Added `Binary` instances for all tuple types. Note that this does incur a
*binary* dependency only because of the tuple types; however, this will
hopefully be not too much of an issue because *binary* is a GHC library
anyway.
Version 0.1.5.0
---------------
*Mar 30, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.5.0>
* `T` added to *Numeric.Backprop.Tuple*: basically an `HList` with a `Num`
instance.
* `Eq` and `Ord` instances for `BVar`. Is this sound?
*Internal*
* Refactored `Monoid` instances in *Numeric.Backprop.Tuple*
Version 0.1.4.0
---------------
*Mar 25, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.4.0>
* `isoVar`, `isoVar2`, `isoVar3`, and `isoVarN`: convenient aliases for
applying isomorphisms to `BVar`s. Helpful for use with constructors and
deconstructors.
* `opIso2` and `opIso3` added to *Numeric.Backprop.Op*, for convenience.
* `T0` (Unit with numeric instances) added to *Numeric.Backprop.Tuple*.
*Internal*
* Completely decoupled the internal implementation from `Num`, which showed
some performance benefits. Mostly just to make the code slightly cleaner,
and to prepare for some day potentially decoupling the external API from
`Num` as well.
Version 0.1.3.0
---------------
*Feb 12, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.3.0>
* *Preulude.Backprop* module added with lifted versions of several *Prelude*
and base functions.
* `liftOpX` family of operators now have a more logical ordering for type
variables. This change breaks backwards-compatibility.
* `opIsoN` added to export list of *Numeric.Backprop*
* `noGrad` and `noGrad1` added to *Numeric.Backprop.Op*, for functions with
no defined gradient.
*Internal*
* Completely decoupled the internal implementation from `Num`, which showed
some performance benefits.
Version 0.1.2.0
---------------
*Feb 7, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.2.0>
* Added currying and uncurrying functions for tuples in
*Numeric.Backprop.Tuple*.
* `opIsoN`, for isomorphisms between a tuple of values and a value.
* (Internal) AD engine now using `Any` from *ghc-prim* instead of `Some I`
from *type-combinators*
Version 0.1.1.0
---------------
*Feb 6, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.1.0>
* Added canonical strict tuple types with `Num` instances, in the module
*Numeric.Backprop.Tuple*. This is meant to be a band-aid for the problem
of orphan instances and potential mismatched tuple types.
* Fixed bug in `collectVar` that occurs if container sizes change
*Internal*
* Internal tweaks to the underlying automatic differentiation types that
decouple backpropagation from `Num`, internally. `Num` is now just used
externally as a part of the API, which might someday be made optional.
Version 0.1.0.0
---------------
*Feb 5, 2018*
<https://github.com/mstksg/backprop/releases/tag/v0.1.0.0>
* First non-alpha release.
* More or less complete redesign of library. The entire API is completely
changed, and there is no backwards compatibility!
* Everything is now "implicit" style, and there is no more `BP` monad.
* Accessing items in `BVar`s is now lens-, prism-, and traversal- based,
instead of iso- and generics-based.
* `Op` is no longer monadic
* *Mono* modules are removed.
* *Implicit* modules are removed, since they are the default
* *Iso* module is removed, since `Iso`s no longer play major role in the
implementation of the library.
* Removed dependency on *ad* and *ad*-based ops, which had been pulling in
the vast majority of dependencies.
* Moved from *.cabal* file to *hpack* system.
Version 0.0.3.0
---------------
*Alpha*
<https://github.com/mstksg/backprop/releases/tag/v0.0.3.0>
* Removed samples as registered executables in the cabal file, to reduce
dependences to a bare minimum. For convenience, build script now also
compiles the samples into the local directory if *stack* is installed.
* Added experimental (unsafe) combinators for working with GADTs with
existential types, `withGADT`, to *Numeric.Backprop* module.
* Fixed broken links in changelog.
Version 0.0.2.0
---------------
*Alpha*
<https://github.com/mstksg/backprop/releases/tag/v0.0.2.0>
* Added optimized numeric `Op`s, and re-write `Num`/`Fractional`/`Floating`
instances in terms of them.
* Removed all traces of `Summer`/`Unity` from the library, eliminating a
whole swath of "explicit-Summer"/"explicit-Unity" versions of functions.
As a consequence, the library now only works with `Num` instances. The
API, however, is now much more simple.
* Benchmark suite added for MNIST example.
Version 0.0.1.0
---------------
*Alpha*
<https://github.com/mstksg/backprop/releases/tag/v0.0.1.0>
* Initial pre-release, as a request for comments. API is in a usable form
and everything is fully documented, but there are definitely some things
left to be done. (See [README.md][readme-0.0.1.0])
[readme-0.0.1.0]: https://github.com/mstksg/backprop/tree/v0.0.1.0#readme