Changelog for backprop-0.1.5.0

Changelog

Mar 30, 2018

T added to Numeric.Backprop.Tuple: basically an HList with a Num instance.
Eq and Ord instances for BVar. Is this sound?

Internal

Mar 25, 2018

isoVar, isoVar2, isoVar3, and isoVarN: convenient aliases for applying isomorphisms to BVars. 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.

Feb 12, 2018

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.

Feb 7, 2018

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

Feb 6, 2018

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.

Feb 5, 2018

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 BVars 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 Isos 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.

Alpha

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.

Alpha

Added optimized numeric Ops, 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.

Alpha

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)