Beam/Beam.Models/ImmutableState.cs

using System.Text.Json.Serialization;
using Beam.Abstractions;

namespace Beam.Models {
    public readonly struct ImmutableState : IReadOnlyState {
        private readonly string[] state;

        [JsonConstructor]
        public ImmutableState(params IEnumerable<string> state) {
            this.state = state.ToArray();
        }

        public ReadOnlySpan<string> GetState() => this.state;
        
        public readonly State Copy()
            => new((string[])(state ?? []).Clone());
        IState  IReadOnlyState.Copy()
            => Copy();
        public readonly string this[Index i] => state[i];
        public static implicit operator State(ImmutableState state)
            => state.Copy();
    }
}