provide-0.1.0.0: provide.cabal

cabal-version:       2.2
name:                provide
version:             0.1.0.0
synopsis:            Lightweight dependency injection / namespaced+typed implicit-ish arguments
description:
  In many applications, there are arguments that need to be passed deeply into call hierarchies, which can be annoying.  Implicit arguments are one potential solution to this, but they have a few issues.  Firstly, their names are based on strings, which can be noncomposable e.g. in the case that multiple libraries choose the same name.  Secondly, the type of an implicit argument can be freely chosen wherever it is used, which is more flexibility than most libraries want.  Thirdly, the semantics of implicit variables is somewhat strange with respect to let bindings, etc.
  This library instead supports associating an unlimited number of values with a context type.  Although this context type does need to be passed down somehow into the child functions, it's only one argument, not many, and it can be passed as a type or as a Proxy value.  The keys of the context are types, which libraries can provide to designate the context arguments they want.
license:             BSD-3-Clause
license-file:        LICENSE
author:              Obsidian Systems LLC
maintainer:          maintainer@obsidian.systems
category:            Data Structures
build-type:          Simple

flag strict
  description: Build with options, such as -Werror, which are inconvenient for development but good for CI
  default: False
  manual: True

common common
  default-extensions:
    AllowAmbiguousTypes
    BangPatterns
    ConstraintKinds
    DataKinds
    DefaultSignatures
    DeriveDataTypeable
    DeriveFoldable
    DeriveFunctor
    DeriveGeneric
    DeriveTraversable
    DerivingStrategies
    EmptyCase
    EmptyDataDecls
    FlexibleContexts
    FlexibleInstances
    FunctionalDependencies
    GADTs
    GeneralizedNewtypeDeriving
    ImportQualifiedPost
    InstanceSigs
    KindSignatures
    KindSignatures
    LambdaCase
    MultiParamTypeClasses
    NumericUnderscores
    OverloadedStrings
    PartialTypeSignatures
    PatternSynonyms
    PolyKinds
    QuantifiedConstraints
    QuasiQuotes
    RankNTypes
    RecursiveDo
    ScopedTypeVariables
    StandaloneDeriving
    TemplateHaskell
    TypeApplications
    TypeFamilies
    TypeOperators
    UndecidableInstances
    ViewPatterns
  if flag(strict)
    ghc-options:
      -Werror
      -Wunused-packages
  ghc-options: -Wall -fno-show-valid-hole-fits
               -- unnecessary checks
               -Wno-partial-type-signatures
               -- unsafe code
               -Wincomplete-record-updates -Werror=incomplete-record-updates
               -Wincomplete-patterns -Werror=incomplete-patterns
               -Wincomplete-uni-patterns -Werror=incomplete-uni-patterns
               -Wpartial-fields -Werror=partial-fields
               -Wmissing-fields -Werror=missing-fields
               -- unneeded code
               -Widentities
               -Wredundant-constraints
  if impl(ghc >= 8.8)
    ghc-options:
               -Wmissing-deriving-strategies
               -Werror=missing-deriving-strategies

library
  import: common
  hs-source-dirs: src
  exposed-modules:
    Control.Provide
    Control.Provide.ARec
  build-depends:
    base >= 4.9 && < 5,
    lens >= 5.3 && < 5.4,
    reflection >= 2.1 && < 2.2,
    vinyl >= 0.14 && <0.15
  default-language: Haskell2010

test-suite example
  import: common
  main-is: example.hs
  type: exitcode-stdio-1.0
  build-depends:
    base,
    provide,
    vinyl
  default-language: Haskell2010