Metadata-Version: 2.1
Name: haskpy
Version: 0.2.0
Summary: Utilities inspired by Haskell and Hask category
Home-page: UNKNOWN
Author: Jaakko Luttinen
Author-email: jaakko.luttinen@iki.fi
License: UNKNOWN
Project-URL: Homepage, https://github.com/jluttine/haskpy
Project-URL: Documentation, https://jluttine.github.io/haskpy/
Project-URL: Bug reports, https://github.com/jluttine/haskpy/issues
Project-URL: Contributing, https://github.com/jluttine/haskpy/pulls
Project-URL: Forum, https://github.com/jluttine/haskpy/discussions
Description: # HaskPy - Haskell types and functions in Python
        
        Hask is the category of types and functions in Haskell. This package provides
        classes and functions inspired by Hask.
        
        Documentation is available at [jluttine.github.io/haskpy](https://jluttine.github.io/haskpy/).
        
        [![Test status](https://github.com/jluttine/haskpy/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/jluttine/haskpy/actions/workflows/test.yml)
        [![Release](https://img.shields.io/pypi/v/haskpy.svg)](https://pypi.org/project/haskpy/)
        
        
        ## Overview
        
        ### Features
        
        - Typeclasses: `Functor`, `Applicative`, `Monad`, `Semigroup`, `Monoid`,
          `Commutative`, `Foldable`, `Contravariant`, `Profunctor`, `Cartesian`,
          `Cocartesian`
        
          - **TODO:** `Traversable`, `Bifunctor`, `Monoidal`, `Ord`, `Show`, `Read`
        
        - Types and type constructors: `Identity`, `Maybe`, `Either`, `List`,
          `Function`, `Compose`, `LinkedList`
        
          - **TODO:** `Constant`, `Validation`, `Dictionary`, `State`, `Reader`,
            `Writer`, `IO`
        
        - Monad transformers: `MaybeT`, `IdentityT`
        
          - **TODO:** `StateT`, `ReaderT`, `WriterT`, `ListT`
        
        - Simple monoids: `Sum`, `All`, `Any`, `String`, `Endo`
        
          - **TODO:** `Product`
        
        - Profunctor optics: `adapter`, `lens`, `prism`
        
          - **TODO**: `traversal`, `grate`, `affine`, `setter`
        
        - Operators for common tasks: ``**`` for function composition or functorial
          mapping, ``@`` for applicative application, ``%`` for monadic binding and
          ``>>`` for applicative/monadic sequencing.
        
        - Property-based testing of typeclass laws
        
        HaskPy has implemented typeclass laws as property-based tests. Thus, one can
        easily test that an implementation satisfies all the laws it should. Just add
        something like this to your test module and run with pytest:
        
        ```python
        from haskpy.utils import make_test_class
        from mystuff import MyClass
        TestMyClass = make_test_class(MyClass)
        ```
        
        This will automatically verify that `MyClass` satisfies all the typeclass laws
        of those typeclasses that it inherits. It makes use of great [Hypothesis
        package](https://hypothesis.readthedocs.io/en/latest/).
        
        
        ## Examples
        
        ### Functors
        
        A minimal example of functorial mapping:
        
        ```python
        >>> from haskpy import map, List
        >>> map(lambda x: x**2, List(1, 2, 3, 4, 5))
        List(1, 4, 9, 16, 25)
        ```
        
        Lift over two layers of functorial structure:
        
        ```python
        >>> from haskpy import map, List, Just, Nothing
        >>> map(map(lambda x: x**2))(List(Just(1), Nothing, Just(3), Just(4), Nothing))
        List(Just(1), Nothing, Just(9), Just(16), Nothing)
        ```
        
        Note that `haskpy.map` works for all Functor instances. That is, you don't need
        to use a different function to lift over different functors. You can even create
        function that performs some operation to values contained in any two-layer
        functorial structure. In the following example, `square` squares the values
        inside a two-layer functor:
        
        ```python
        >>> square = map(map(lambda x: x**2))
        >>> square(List(Just(1), Nothing, Just(3)))
        List(Just(1), Nothing, Just(9))
        >>> square(List(List(1, 2, 3), List(4, 5)))
        List(List(1, 4, 9), List(16, 25))
        ```
        
        Even functions are functors if they have been decorated with `function`:
        
        ```python
        >>> @function
        ... def f(x):
        ...     return List(x, 2*x, 3*x)
        >>> square(f)(3)
        List(9, 36, 81)
        ```
        
        ### Functions
        
        HaskPy provides type `Function` for functions so that they have, for instance,
        `Functor` and `Monad` implementations. These functions are curried and they
        should only take a fixed number of arguments (no optional arguments and at least
        one argument). Decorator `function` just converts a normal Python function into
        a curried `Function` object:
        
        ```python
        >>> from haskpy import curry
        >>> @function
        ... def concat(x, y, z):
        ...    return x + y + z
        >>> concat("a")("b")("c")
        "abc"
        >>> concat("a")("b", "c")
        "abc"
        ```
        
        Note that it doesn't convert the function into nested one-argument functions (as
        currying strictly speaking should do) but it gives more flexibility by accepting
        any number of arguments (even no arguments at all). Keyword arguments aren't
        supported because of consistency.
        
        Almost all functions in HaskPy have been decorated with `function`.
        
        
        ## Copyright
        
        Copyright (C) 2019-2021 Jaakko Luttinen
        
        HaskPy is licensed under the MIT License. See LICENSE file for a text of the
        license or visit http://opensource.org/licenses/MIT.
        
Keywords: functional programming,category theory,Hask category,Haskell,functor,applicative,monad,monoid
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Development Status :: 3 - Alpha
Classifier: Environment :: Console
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Topic :: Scientific/Engineering
Classifier: Topic :: Software Development :: Libraries
Description-Content-Type: text/markdown
Provides-Extra: dev
Provides-Extra: doc
