Narochno.Primitives

Classes designed to make working with C# code easier.

NotNull and Empty

Helpers that remove of the constant issues around checking null on all types and collections. If you find yourself doing "if not then throw" or "null or empty collection" then these help you out.

Generic Parsing

A set of classes to provide parsing of strings into types. Allows a single generic function call to invoke parsers for all primitive types, extendable to be used with custom types.

The library also adds support for enum string values.

Example .Parse<T> Usage

The string extension method .Parse<T> or .Parse(type) can be used to parse a string to a specific type, and throw an exception if the parse fails.

int number = "20".Parse<int>();
float floating = "20.25".Parse<float>();

Example .TryParse<T> Usage

The string extension method .TryParse<T> or .TryParse(type) can be used to parse a string to a specific type, returning a Nullable result (and no exception if the parse fails).

int? optionalNumber = "10".TryParse<int>();
float? optionalFloat = "10.1".TryParse<float>();

Example Enum String Parsing

The library can be used to parse strings to enum values decorated with the EnumString attribute.

public enum MyEnum
{
    [EnumString("first")]
    One,
    [EnumString("second")]
    Two
}

MyEnum parsed = "second".Parse<MyEnum>();

Extending Parsers

A custom parser will need to inherit from the Parser class, which requires the implementation of two methods.

public class BoolParser : Parser<bool>
{
    public override bool Parse(string input) => bool.Parse(input);

    public override bool? TryParse(string input)
    {
        bool result;
        if (bool.TryParse(input, out result))
        {
            return result;
        }
        return null;
    }
}

Additional parsers can be added for the static string extension methods .Parse and .TryParse by adding to the static Parsers dictionary in DefaultParserLibrary.

DefaultParserLibrary.Parsers.Add(typeof(MyType), new MyTypeParser());

Parsing in a Non-Static Context

The parsing library provides the DefaultParserLibrary.Instance static for convenience. This can be re-assigned in your application to anything that implements the interface IParserLibrary.

The DefaultParserLibrary can also be instantiated, and used as follows, completely avoiding the static extensions.

var parser = new DefaultParserLibrary()
    .GetParser<bool>();

bool itIsTrue = parser.Parse<bool>("true");

Parsing can be used with dependency injection - simply register DefaultParserLibrary against the interface IParserLibrary in your container and inject into your class constructor. Using the library this way allows you to mock its methods in unit tests.

var provider = new ServiceCollection()
    .AddTransient<IParserLibrary, DefaultParserLibrary>()
    .BuildServiceProvider();