Files
LuaCsForBarotraumaEP/Barotrauma/BarotraumaShared/SharedSource/Utils/ReflectionUtils.cs
Juan Pablo Arce 1219615d64 Unstable v0.19.1.0
2022-08-19 13:59:08 -03:00

60 lines
2.5 KiB
C#

#nullable enable
using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Reflection;
namespace Barotrauma
{
public static class ReflectionUtils
{
private static readonly Dictionary<Assembly, ImmutableArray<Type>> cachedNonAbstractTypes
= new Dictionary<Assembly, ImmutableArray<Type>>();
public static IEnumerable<Type> GetDerivedNonAbstract<T>()
{
Assembly assembly = typeof(T).Assembly;
if (!cachedNonAbstractTypes.ContainsKey(assembly))
{
cachedNonAbstractTypes[assembly] = assembly.GetTypes()
.Where(t => !t.IsAbstract).ToImmutableArray();
}
return cachedNonAbstractTypes[assembly].Where(t => t.IsSubclassOf(typeof(T)));
}
public static Option<T1> ParseDerived<T1>(string str)
{
static Option<T1> none() => Option<T1>.None();
var derivedTypes = GetDerivedNonAbstract<T1>();
Option<T1> parseOfType(Type t)
{
//every T1 type is expected to have a method with the following signature:
// public static Option<T> Parse(string str)
var parseFunc = t.GetMethod("Parse", BindingFlags.Public | BindingFlags.Static);
if (parseFunc is null) { return none(); }
var parameters = parseFunc.GetParameters();
if (parameters.Length != 1) { return none(); }
var returnType = parseFunc.ReturnType;
if (!returnType.IsConstructedGenericType) { return none(); }
if (returnType.GetGenericTypeDefinition() != typeof(Option<>)) { return none(); }
if (returnType.GenericTypeArguments[0] != t) { return none(); }
//some hacky business to convert from Option<T2> to Option<T1> when we only know T2 at runtime
static Option<T1> convert<T2>(Option<T2> option) where T2 : T1
=> option.Select(v => (T1)v);
Func<Option<T1>, Option<T1>> f = convert;
var constructedConverter = f.Method.GetGenericMethodDefinition().MakeGenericMethod(typeof(T1), t);
return constructedConverter.Invoke(null, new object?[] { parseFunc.Invoke(null, new object[] { str }) })
as Option<T1> ?? none();
}
return derivedTypes.Select(parseOfType).FirstOrDefault(t => t.IsSome()) ?? none();
}
}
}