File ghc-lens-simple.spec of Package ghc-lens-simple
#
# spec file for package ghc-lens-simple
#
# Copyright (c) 2017 SUSE LINUX GmbH, Nuernberg, Germany.
#
# All modifications and additions to the file contributed by third parties
# remain the property of their copyright owners, unless otherwise agreed
# upon. The license for this file, and modifications and additions to the
# file, is the same license as for the pristine package itself (unless the
# license for the pristine package is not an Open Source License, in which
# case the license is the MIT License). An "Open Source License" is a
# license that conforms to the Open Source Definition (Version 1.9)
# published by the Open Source Initiative.
# Please submit bugfixes or comments via http://bugs.opensuse.org/
#
%global pkg_name lens-simple
Name: ghc-%{pkg_name}
Version: 0.1.0.9
Release: 0
Summary: Simplified import of elementary lens-family combinators
License: BSD-3-Clause
Group: Development/Libraries/Haskell
URL: https://hackage.haskell.org/package/%{pkg_name}
Source0: https://hackage.haskell.org/package/%{pkg_name}-%{version}/%{pkg_name}-%{version}.tar.gz
BuildRequires: ghc-Cabal-devel
BuildRequires: ghc-lens-family-core-devel
BuildRequires: ghc-lens-family-devel
BuildRequires: ghc-lens-family-th-devel
BuildRequires: ghc-mtl-devel
BuildRequires: ghc-rpm-macros
BuildRequires: ghc-transformers-devel
%description
This module,
<http://hackage.haskell.org/package/lens-simple/docs/Lens-Simple.html
Lens.Simple>, just re-exports the main modules from Russell O'Connor's
<http://hackage.haskell.org/package/lens-family lens-family> package, the
original van Laarhoven-O'Connor lens library. 'lens-family' is particularly
remarkable for its minute number of dependencies: (apart from
<http://hackage.haskell.org/package/mtl mtl> they are all ghc 'boot'
libraries); but more importantly for its extreme conceptual simplicity and
theoretical soundness. Much of the material it contains is well-explained, from
a tutorial point of view, by <http://hackage.haskell.org/package/lens-tutorial
lens-tutorial> It is independent, self-standing and readily intelligible apart
from any darker more general system of combinators that might attempt to extend
it. Much of it ought to be in the Prelude.
Convenient import of the elementary combinators from 'lens-family', however, a
little complicated. The idea of this trivial module, then, is just to make a
sort of low-powered, minimal-dependency, 'lens-family' equivalent of the 800 lb
gorilla of lens library imports:
> import Control.Lens
namely, the light-weight and elegant:
> import Lens.Simple
Check it out, it's even one character shorter!
The material in <http://hackage.haskell.org/package/lens-tutorial
lens-tutorial> will work fine if you make this substitution in the underlying
<http://hackage.haskell.org/package/lens-tutorial-1.0.0/docs/src/Control-Lens-Tutorial.html
source> and follow along as prompted.
As another illustration of the simplicity of the fundamental van
Laarhoven-O'Connor lens combinators - and their homogeneity with 'Control.Lens'
- note that the gloss
<https://github.com/michaelt/lens-family-simple/blob/master/examples/Pong.hs
pong example> from the 'lens' library examples directory - which continues to
be among the best introductory lens tutorials precisely by saying nothing -
requires only this abbreviating change of imports.
If you make that program more complicated, you might of course end up needing
the more sophisticated material in 'Control.Lens' and its immense mass of
dependencies. On the other hand, you might just need some of the additional
material present in the similarly demystifying
<http://hackage.haskell.org/package/microlens microlens> or
<http://hackage.haskell.org/package/microlens-th microlens-th> and the
associated modules.
This module was originally intended to simplify the use of packages that follow
the original promise of the van Laarhoven-O'Connor lenses. /Correct practice is
to export lenses without depending on a lens-library, where possible./ In basic
cases these just use familiar 'Prelude' types, after all. Examples of best
practices in this respect are e.g.
<http://hackage.haskell.org/package/lens-family-th lens-family-th> which
doesn't depend on 'lens-family' despite its name and pipes-related packages
like <http://hackage.haskell.org/package/pipes-bytestring pipes-bytestring> and
<http://hackage.haskell.org/package/pipes-group pipes-group>.
'Lens.Simple' also re-exports convenient TH incantations like 'makeLenses' from
Dan Burton's associated <http://hackage.haskell.org/package/lens-family-th
lens-family-th>. .
%package devel
Summary: Haskell %{pkg_name} library development files
Group: Development/Libraries/Haskell
Requires: %{name} = %{version}-%{release}
Requires: ghc-compiler = %{ghc_version}
Requires(post): ghc-compiler = %{ghc_version}
Requires(postun): ghc-compiler = %{ghc_version}
%description devel
This package provides the Haskell %{pkg_name} library development files.
%prep
%setup -q -n %{pkg_name}-%{version}
%build
%ghc_lib_build
%install
%ghc_lib_install
%post devel
%ghc_pkg_recache
%postun devel
%ghc_pkg_recache
%files -f %{name}.files
%doc LICENSE
%files devel -f %{name}-devel.files
%doc README.md changelog
%changelog
