Runtime: Feature Request: IParseable<T> interface for all types implementing Parse() and TryParse()

[TheMinefighter]

It would be nice if there was an IParseable<T> interface providing static T Parse(string toParse) and static bool TryParse(string toParse, out T val)
Optionally there could be IFormattableParseable<T> : IParseable<T>, IFormattable providing static T Parse(string toParse, IFormatProvider provider) and static bool TryParse(string toParse, IFormatProvider provider, out T val) .
The IParseable interface should be implemented by all types providing the Parse() and TryParse() method, IFormattableParseable should be implemented by all types additionally implementing IFormattable. T should always be the type itself.

[huoyaoyuan]

Parse are static methods, not instance. So this should need functionals like shape or static interface methods.

[shaggygi]

This sounds interesting, but might be better to start in the corefxlab repo.

[TobiasSekan]

I like this idea 😎

When we have static interfaces, I would prefer this

public static interface IParseable<TType>
{
    TType Parse(string s);
    TType Parse(ReadOnlySpan<char> value)

    bool TryParse(string s, out TType result);
    bool TryParse(ReadOnlySpan<char> value, out TType result);
}

public static interface IFormattableParseable<TType> : IParseable<TType>
{
     TType Parse(string s, NumberStyles style);
     TType Parse(ReadOnlySpan<char> value, NumberStyles style);

     TType Parse(string s, IFormatProvider provider);
     TType Parse(ReadOnlySpan<char> value, IFormatProvider provider);

     TType Parse(string s, NumberStyles style, IFormatProvider provider);
     TType Parse(ReadOnlySpan<char> value, NumberStyles style, IFormatProvider provider);

     bool TryParse(string s, NumberStyles style, out TType result);
     bool TryParse(ReadOnlySpan<char> value, NumberStyles style, out TType result);

     bool TryParse(string s, IFormatProvider provider, out TType result);
     bool TryParse(ReadOnlySpan<char> value, IFormatProvider provider, out TType result);

     bool TryParse(string s, NumberStyles style, IFormatProvider provider, out TType result);
     bool TryParse(ReadOnlySpan<char> value, NumberStyles style, IFormatProvider provider, out TType result);
}

[TheMinefighter]

@TobiasSekan The usage of ReadOnlySpans would make the implementation more work than needed, and might result in developers refusing the implementation of that interface..

[TobiasSekan]

@TheMinefighter
Possible, but I think we need this to increase the performance for heavy usage.

Maybe we can split the ReadOnlySpan<char> in separate interfaces, like this:

public static interface IParseableSpan<TType>
{
    TType Parse(ReadOnlySpan<char> value)

    bool TryParse(ReadOnlySpan<char> value, out TType result);
}

public static interface IFormattableParseableSpan<TType> : IParseableSpan<TType>
{
    TType Parse(ReadOnlySpan<char> value, NumberStyles style);
    TType Parse(ReadOnlySpan<char> value, IFormatProvider provider);
    TType Parse(ReadOnlySpan<char> value, NumberStyles style, IFormatProvider provider);

    bool TryParse(ReadOnlySpan<char> value, NumberStyles style, out TType result);
    bool TryParse(ReadOnlySpan<char> value, IFormatProvider provider, out TType result);
    bool TryParse(ReadOnlySpan<char> value, NumberStyles style, IFormatProvider provider, out TType result);
}