MIT licensed by Nikita Volkov
Maintained by chessai

Module documentation for 0.6.1

This version can be pinned in stack with:refined-0.6.1@sha256:d5d713f0a2ad79d1c049d2d132fd8c2078b883b5ea3db876087eaec102843e57,2748

refined

Build Status

In type theory, a refinement type is a type endowed with a predicate which is assumed to hold for any element of the refined type.

This library allows one to capture the idea of a refinement type using the Refined type. A Refined p x wraps a value of type x, ensuring that it satisfies a type-level predicate p.

A simple introduction to this library can be found here: http://nikita-volkov.github.io/refined/

Changes

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 the Haskell Package Versioning Policy.

[0.6.1] - 2020-08-02

Changed

  • upper bound on QuickCheck: <2.14 -> <2.15

[0.6] - 2020-07-21

Changed

  • strengthen no longer returns an Either, since the proof that it should always succeed is in its constraints.
  • validate now takes a Proxy as its first argument.
  • All uses of prettyprinter are now just Text

Removed

  • Refined.These module
  • Dependency on prettyprinter

Fixed

  • bug in sized internal helper that caused formatting issues in sized predicate errors

[0.5.1] - 2020-07-14

Changed

  • refineTH_ is now implemented in terms of refineTH
  • Fix pretty-printing of RefineExceptions during compile-time

[0.5] - 2020-07-11

Added

  • sized Predicate instances for Text
  • sized Predicate instances for strict and lazy ByteString
  • INLINABLE pragmas on refine_ reifyPredicate
  • NFData instance for Refined
  • RefineSomeException constructor. Enables recovering specific validation exceptions. Thanks to @haroldcarr for adding this.
  • RefineXorException constructor.
  • Empty and NotEmpty predicates.
  • NaN and Infinite predicates for floating-point numbers.
  • @since pragmas to EVERYTHING.

Changed

  • lower bound on mtl to 2.2.2 due to use of liftEither. Thanks to @k0ral for reporting this
  • Generalize sized predicates
  • Allow newer template-haskell (< 0.16 ==> < 0.17)
  • Allow newer aeson (< 1.5 ==> < 1.6) Thanks to @locallycompact for this change.

Removed

  • Refined.Internal module Thanks to @nikita-volkov for pushing me to do this.
  • Orphan modules Thanks to @symbiont-sam-halliday for pointing out the silliness of these modules.
  • RefineT. It was a needless abstraction that just made the library harder to learn and use, providing little benefit over Maybe RefineException. Thanks to @nikita-volkov for helping me see the light.

Deprecated

  • Refined.These module in favour of Data.These from these-skinny

[0.4.4] - 2019-10-18

Added

  • refine_
  • refineTH_
  • test suite: unit tests for compiling.

Changed

  • Allow newer template-haskell and QuickCheck.

[0.4.2.3] - 2019-09-17

Added

  • reifyPredicate

Fixed

  • Arbitrary instance for Refined should now always terminate. Thanks to @symbiont-joseph-kachmar for reporting this.

[0.4.2.2] - 2019-07-19

Added

  • exceptRefine, strengthen, and strengthenM

[0.4.2.1] - 2019-05-31

Fixed

  • Documentation fix for DivisibleBy

Changed

  • Re-export DivisibleBy, Even, and Odd from module Refined.
  • Re-export all constructors from module Refined.

[0.4.2] - 2019-05-30

Removed

  • Re-removed dependency of these package.

Added

  • Even, Odd, and DivisibleBy predicates.
  • doctests for all predicates.

Changed

  • Make all predicates unary data constructors, instead of nullary, and export those newly added constructors.

[0.4.1] - 2019-04-15

Fixed

  • Serious regression where Not p ~ p. Thanks to @k0ral who reported this.

[0.4] - 2019-03-18

Added

  • ‘NegativeFromTo’, a Predicate that ensures a numeric value is within a range [a,b], where a < 0 and b >= a. Thanks to github.com/futtetennista for this change.

Changed

  • RefinedNotException now has a child (it should have had one in v2. This was an oversight.)
  • displayRefineException no longer uses tabs, instead 2 spaces.
  • make implementation of displayRefineException more clear via formatting.

[0.3.0.0] - 2018-09-26

Added

  • Internal module, and Unsafe modules, making sure to take care w.r.t. the scope of coercions related to the use of the ‘Refined’ constructor.
  • ‘IdPred’ predicate, predicate that never fails.
  • Generic instances for all predicates.
  • reallyUnsafeRefine, reallyUnsafeUnderlyingRefined, reallyUnsafeAllUnderlyingRefined, functions that allow one to use ‘Coercion’s to manually prove things about ‘Refined’ values.

Changed

  • Type role of Refined from ‘phantom Representational’ to ‘nominal nominal’. With the old type role, one can use coerce to prove Q x given any P x. The second parameter should also be nominal because of interactions with something like GreaterThan and Data.Ord.Down. Thanks to David Feuer for pointing this out.
  • Change docs to point users to ‘Refined.Unsafe’ module instead of recommending ‘Unsafe.Coerce.unsafeCoerce’.
  • ‘Ascending’ and ‘Descending’ predicates now use ‘Foldable’ instead of ‘IsList’.
  • Lowered the lower bound on ‘exceptions’; it was too strict for the support window.

Removed

  • Dependency of the ‘these’ package. It brings in some very heavy transitive dependencies, even though the datatype in refined is used to the most minimal extent. This is a breaking change because this change is exposed to the end user via ‘RefineAndException’. It is exported from a module called ‘Refined.These’. Users wishing to interact with such exceptions can either just use the datatype constituting a minimal API there, or depend on the ‘these’ package.

[0.2.3.0] - 2018-06-01

Added

  • back in the ‘Foldable’ instance for ‘Refined’. It is safe.

[0.2.2.0] - 2018-05-31

Removed

  • Unsafe typeclass instances that could break the ‘Refined’ invariant. These should not have been added.

[0.2.1.0] - 2018-05-31

Removed

  • Unsafe typeclass instances that could break the ‘Refined’ invariant. These should not have been added.

[0.2.0.0] - 2018-05-30

Changed

  • Radical rewrite of the library, centred around ‘RefineException’ and the ‘RefineT’ monad transformer. ‘validate’ now has the type signature validate :: (Predicate p x, Monad m) => p -> x -> RefineT m ()

Added

  • More predicates