Name: fclabels Version: 2.0 Author: Sebastiaan Visser, Erik Hesselink, Chris Eidhof, Sjoerd Visscher with lots of help and feedback from others. Synopsis: First class accessor labels implemented as lenses. Description: This package provides first class labels that can act as bidirectional record fields. The labels can be derived automatically using Template Haskell which means you don't have to write any boilerplate yourself. The labels are implemented as /lenses/ and are fully composable. Lenses can be used to /get/, /set/ and /modify/ parts of a data type in a consistent way. . See "Data.Label" for an introductory explanation or see the introductory blog post at . * /Total and partial lenses/ . Internally lenses do not used Haskell functions directly, but are implemented as categories. Categories allow the lenses to be run in custom computational contexts. This approach allows us to make partial lenses that point to fields of multi-constructor datatypes in an elegant way. . See "Data.Label.Partial" for the use of partial labels. . * /Monomorphic and polymorphic lenses/ . We have both polymorphic and monomorphic lenses. Polymorphic lenses allow updates that change the type. The types of polymorphic lenses are slightly more verbose than their monomorphic counterparts, but their usage is similar. Because monomorphic lenses are built by restricting the types of polymorphic lenses they are essentially the same and can be freely composed with eachother. . See "Data.Label.Mono" and "Data.Label.Poly" for the difference between polymorphic and monomorphic lenses. . * /Using fclabels/ . To simplify working with labels we supply both a set of labels for Haskell's base types, like lists, tuples, Maybe and Either, and we supply a set of combinators for working with labels for values in the Reader and State monad. . See "Data.Label.Base" and "Data.Label.Monadic" for more information. . * /Changelog from 1.1.7.1 to 2.0/ . > - Introduced polymorphic lenses. > - Lenses are now based on getters and modifiers, not getters and setters. > - Pure lenses are now named Total lenses. > - Maybe lenses are now named Partial lenses. > - Introduced Failing lenses that preserve errors. > - Generalized Point data type. > - Removed unused monadic functions for partial lenses. > - Added ArrowFail type class. > - Added lenses for base types. (tuples, lists, Maybe, Either) > - Isomorphisms now uses regular function space for base morphism. > - Swapped iso for more useful inv. > - Introduced iso to more easily lift isomorphisms into lenses. > - Removed mainly unused bimap. > - Added derivation of lenses as expressions. > - Convert record declarations directly into fclabels variants. > - Allow deriving lenses for GADTs. > - Added reasonably sophisticated totality checker for GADT labels. > - Derived lenses can now fail in either ArrowZero or ArrowFail. > - Alternative instance for Point. > - Vertical composition for multi-constructor data types. > - Extensive test suite. > - Fully documented. Maintainer: Sebastiaan Visser Homepage: https://github.com/sebastiaanvisser/fclabels Bug-Reports: http://github.com/sebastiaanvisser/fclabels/issues License: BSD3 License-File: LICENSE Category: Data, Lenses Cabal-Version: >= 1.6 Build-Type: Simple Library HS-Source-Dirs: src Exposed-Modules: Data.Label Data.Label.Base Data.Label.Derive Data.Label.Failing Data.Label.Monadic Data.Label.Mono Data.Label.Partial Data.Label.Point Data.Label.Poly Data.Label.Total GHC-Options: -Wall Build-Depends: base < 5 , template-haskell >= 2.2 && < 2.9 , mtl >= 1.0 && < 2.2 , transformers >= 0.2 && < 0.4 Source-Repository head Type: git Location: git://github.com/sebastiaanvisser/fclabels.git