IProvider

IProvider is an interface for key-to-value providers. (Namespace Avalanche.Utilities.Provider)

/// <summary></summary>
public interface IProvider
{
    /// <summary>Key type</summary>
    Type Key { get; }
    /// <summary>Value type</summary>
    Type Value { get; }
    /// <summary>Get value that corresponds <paramref name="key"/></summary>
    /// <exception cref="InvalidCastException">If key is wrong type.</exception>
    bool TryGetValue(object key, out object value);
}

IProvider<Key, Value> is for strong generics typed providers.

/// <summary></summary>
public interface IProvider<Key> : IProvider { }
/// <summary></summary>
public interface IProviderOf<Value> : IProvider { }
/// <summary></summary>
public interface IProvider<Key, Value> : IProvider<Key>, IProviderOf<Value>
{
    /// <summary>Key to value indexer</summary>
    /// <exception cref="KeyNotFoundException">If <paramref name="key"/> is not found.</exception>
    Value this[Key key] { get; }

    /// <summary>Try get <typeparamref name="Value"/> that corresponds <paramref name="key"/></summary>
    bool TryGetValue(Key key, out Value value);
}

Provider can be used with indexer. If input is not found KeyNotFoundException is thrown.

// Create provider
IProvider<double, double> squareProvider = Providers.Func<double, double>(d => d * d);
// Use with indexer[value]
WriteLine(squareProvider[10.0]); // -> "100"

.TryGetValue(input, out output) tries to get a value. It doesn't throw errors on expected failure cases. The line between expected and unexpected failures is stated in the contract of the implementing class.

// Create provider
IProvider<double, double> squareProvider = Providers.Func<double, double>(d => d * d);
// Try Get value
if (squareProvider.TryGetValue(10.0, out double squared))
    WriteLine(squared); // -> "100"

IProvider operates with object input and output.

// Create provider
IProvider squareProvider = Providers.Func<double, double>(d => d * d);
//
object input = 10.0;
// Try Get value
if (squareProvider.TryGetValue(input, out object squaredObject))
    WriteLine(squaredObject); // -> "100"

Full Example

Full example

using Avalanche.Utilities.Provider;
using static System.Console;

class provider_index
{
    public static void Run()
    {
        {
            // <01>
            // Create provider
            IProvider<double, double> squareProvider = Providers.Func<double, double>(d => d * d);
            // Use with indexer[value]
            WriteLine(squareProvider[10.0]); // -> "100"
            // </01>
        }
        {
            // <02>
            // Create provider
            IProvider<double, double> squareProvider = Providers.Func<double, double>(d => d * d);
            // Try Get value
            if (squareProvider.TryGetValue(10.0, out double squared))
                WriteLine(squared); // -> "100"
            // </02>
        }
        {
            // <03>
            // Create provider
            IProvider squareProvider = Providers.Func<double, double>(d => d * d);
            //
            object input = 10.0;
            // Try Get value
            if (squareProvider.TryGetValue(input, out object squaredObject))
                WriteLine(squaredObject); // -> "100"
            // </03>
        }

    }


}