CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

Changed

• Compat compat now includes version 4
• StructEquality is pushed to version 2.0

[1.1.0] - 2021-07-23

Added

• neutral can be used as generic neutral value. With this every Semigroup is automatically a Monoid.
• neutral(type) now defaults to returning neutral instead of throwing a not-implemented-error.

Changed

• pure(Writer, value) now initializes the accumulator to TypeClasses.neutral instead of Option(), making it strictly more general with regard to TypeClasses.combine.

Removed

• reduce_monoid, foldl_monoid and foldr_monoid can now only be called as reduce_monoid(iterable; [init]). The older variant reduce_monoid(combine_function, iterable; [init]) was a left over from previous thrown-away iterations.

[1.0.0] - 2021-07-16

Added

• extensive documentation is ready
• re-exporting DataTypesBasic (Option, Try, Either, ContextManager)
• Writer implements neutral and combine now, analog to Pair and Tuple
• Writer implements pure, falling back to Option() as the generic neutral value. The user needs to wrap their accumulator into an Option to make use of this default.
• new method getaccumulator is exported to access the accumulator of an Writer. Access its value with Base.get.
• Dictionaries.AbstractDictionary is supported, however only loaded if Dictionaries is available, so no extra dependency.
• AbstractVector type-class instances now generalises the previous Vector instances.
• Base.run is now defined for State as an alias for just calling it
• when running a State you now do not need to provide an initial state, in that case it defaults to nothing.
• ↠ operator is added, defined as a ↠ b = flatmap(_ -> b, a), and semantically kind of the reverse of orelse.
• ↠, orelse (⊘), combine (⊕) have now multi-argument versions (i.e. they can take more than 2 arguments).
• added flip_types implementation for Dict
• for convenience, Base.map(f, a, b, c...) is defined as an alias for TypeClasses.mapn(f, a, b, c...) for the data types Option, Try, Either, ContextManager, Callable, Writer, and State.
• Base.Nothing now implements neutral and combine, concretely, neutral(nothing) == nothing and nothing ⊕ nothing == nothing. This was added to support combine on Option in general.

Changed

• ap has a default implementation now, using flatmap and map. This is added because most user will be easily familiar with flatmap and map, and can define those easily. Hence this fallback simplifies the usage massively. Also there is no method ambiguity threat, because ap dispatches on both the function and monad argument with the concrete type, so everything is safe.
• changed orelse alias ⊛ to ⊘ for better visual separation, the latex name \oslash which fits semantically kind of, and because the original reasoning was an misunderstanding.
• Task and Future now have an orelse implementation which parallelizes runs and returns the first result
• flatmap for Identity is now defined as flatmap(f, a::Identity) = f(a.value), i.e. there is no call to convert(Identity, ...) any longer, which makes composing Monads even simpler (Furthermore this gets rid of the need of converting a Const to an Identity which was more a hack beforehand).
• neutral for Identity now always returns Const(nothing).
• updated TagBot
• updated CompatHelper

Fixed

• neutral for Either now returns Const, which is accordance to the Monoid laws.

Removed

• orelse is no longer forwarded to inner elements, as this function is usually defined on a container level.

[0.6.1] - 2021-03-30

Added

• CI/CD pipeline
• Minimal Docs using Documenter
• Codecovering
• TagBot & CompatHelper
• License

Changed

• parts from the README went to the docs

[0.6.0] - 2021-03-29

Removed

• Trait functions have been removed.

  I.e. there is no longer isMonad or isApplicative. The reason is that there is ongoing work on inferring such traits automatically from whether a function is defined or not. As soon as such a generic util exists, the traits would not be needed anylonger. In addition we experienced ambiguities with isSemigroup and isMonoid, because for some examples, the trait affiliation would be defined by the eltype, but eltype is an instable characteristic and hence not recommended to use. We circumvent this problem for now by just not providing the traits.

• Removed dependency on WhereTraits.jl.

  This makes the package for more independent and easier to maintain. We loose some flexibility in multiple dispatch, and instead assume stronger constraints on how the functions should be used.

• Removed absorbing function. It was no where really used. To simplify maintenance we take it out for now.

• Removed change_eltype function

  During the development of this package we initially used a further function, quite related to eltype, called change_eltype. It took a container type like Vector and tried to change its ElementType, e.g. change_eltype(Vector{Int}, String) == Vector{String}. While this may seem intuitively reasonable for example to define isAp, namely to check whether for some Container Container the key function ap is defined for ap(::Container{Function}, ::Container), this is a version of dispatching on eltype and hence should be avoided.

  The resolution is that we assume ap is always overloaded with the first argument being of the general Container-type, i.e. without any restrictions to the eltype.

Changed

• Writer no longer checks whether the accumulator defines the Semigroup interface. This is because we dropped the traits function isSemigroup.

[0.5.0] - 2020-03-23

Added

• TypeClasses: Functor, Applicative, Monads, Semigroup, Monoid and flip_types (traversable sequence)
• new DataTypes: Iterable, Callable, Writer, State
• TypeInstances: Iterable, Callable, Writer, State, Future, Task, Tuple, Pair, String, Vector, Dict
• TypeInstances for all of DataTypesBasic.jl: Const, Identity, Either, ContextManager