Metadata-Version: 2.1
Name: meiga
Version: 0.1.1
Summary: A simple, typed and monad-based Result type for Python
Home-page: https://github.com/alice-biometrics/meiga
Author: ALiCE Biometrics
Author-email: support@alicebiometrics.com
License: MIT
Description: meiga
        =====
        
        A simple, typed and monad-based Result type for Python.
        
        This package provides a new type for your Python applications, the Result[Type, Type].
        This Result type allows to define two subtypes, giving us the option to create useful return types.
        
        This package is based in another solutions from another modern languages as the swift-based [Result](https://github.com/antitypical/Result) implementation.
        
        #### Installation 
        
        ~~~
        pip install meiga
        ~~~
        
        #### Getting Started
        
        **meiga** is a framework that give us a simpler, clearer way of handling errors in Python. Use it whenever a class method or a function has the possibility of failure. 
        
        Consider the following example of a function that tries to extract a String (str) for a given key from a Dict.
        
        ~~~
        from meiga import Result, Error
        
        
        class NoSuchKey(Error):
            pass
        
        
        class TypeMismatch(Error):
            pass
        
        
        def string_from_key(dictionary: dict, key: str) -> Result[str, Error]:
            if key not in dictionary.keys():
                return Result(failure=NoSuchKey())
        
            value = dictionary[key]
            if not isinstance(value, str):
                return Result(failure=TypeMismatch())
        
            return Result(success=value)
        ~~~
        
        Result meiga type provides a robust wrapper around the functions.
        Rather than throw an exception, it returns a Result that either contains the String value for the given key, or an ErrorClass detailing what went wrong.
        
        #### Result Type
        
        Let's image we have a dictionary that represent a user info data
        
        ~~~
        >>> user_info = {"first_name": "Rosalia", "last_name": "De Castro", "age": 60}
        ~~~
        
        And we try to obtain **first_name** 
        
        ~~~
        >>> result = string_from_key(dictionary=user_info, key="first_name")
        Result[status: success | value: Rosalia]
        ~~~
        
        You can check the status of the result
        
        ~~~
        >>> result.is_success
        True
        >>> result.is_failure
        False
        ~~~
        
        If the result is a success you can get the expected value
        
        ~~~
        >>> result.value
        Rosalia 
        ~~~
        
        Otherwise, if we try to access an invalid key or a non string value, returned result will be a failure.
        
        ~~~
        >>> result = string_from_key(dictionary=user_info, key="invalid_key")
        Result[status: failure | value: NoSuchKey]
        >>> result.is_failure
        True
        >>> result.value
        NoSuchKey() // Error 
        ~~~
        
        Or
        
        ~~~
        >>> result = string_from_key(dictionary=user_info, key="age")
        Result[status: failure | value: TypeMismatch]
        >>> result.is_failure
        True
        >>> result.value
        TypeMismatch() // Error 
        ~~~
        
        # Handle Result
        
        This framework also allows a method for handling Result type
        
        When the operations is executed with its happy path, handle function returns the success value, as with result.value.
        
        ~~~
        >>> result = string_from_key(dictionary=user_info, key="first_name")
        Result[status: success | value: Rosalia]
        >>> first_name = result.handle()
        Rosalia
        ~~~
        
        On the other hand, if something wrong happens handle function will raise an Exception (ReturnErrorOnFailure)
        
        Additionally, handle a Result with the meiga decorator allows to return a typed error when a sub-function fails.
        
        ~~~
        from meiga import Result, Error
        from meiga.decorators import meiga
        
        @meiga
        def handling_result(key: str) -> Result:
            user_info = {"first_name": "Rosalia", "last_name": "De Castro", "age": 60}
            first_name = string_from_key(dictionary=user_info, key=key).handle() 
            # Do whatever with the name
            name = first_name.lower()
            return Result(success=name)
        ~~~
        
        If key is valid success value would be returned. Otherwise, an Error would be returned.
        
        
        ## Developers
        
        ##### Install requirements
        
        ~~~
        pip install -r requirements/dev.txt
        ~~~
        
        ##### Test
        
        ~~~
        pip install -e . && pytest
        ~~~
        
        ##### Upload to pip 
        
        ~~~
        python setup.py sdist bdist_wheel
        twine upload --repository-url https://upload.pypi.org/legacy/ dist/*
        ~~
Keywords: Result,Monad,Typed,Typing
Platform: UNKNOWN
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Description-Content-Type: text/markdown
