public void EmitWrite(WriterEmitContext context)
{
using (context.GetLocal(typeof(Span <T>), out var span))
{
context.LoadValue();
context.Il.EmitCall(OpCodes.Call, Type.GetProperty(nameof(Memory <T> .Span)).GetGetMethod(), null);
context.Il.Store(span);
using (context.OverrideScope(spanWriter, span))
{
spanWriter.EmitWrite(context);
}
}
}
protected void Enumerate(WriterEmitContext context, Action consumeValue)
{
var il = context.Il;
var getEnumerator = Type.GetMethod(nameof(IEnumerable <int> .GetEnumerator), BindingFlags.FlattenHierarchy | BindingFlags.Public | BindingFlags.Instance);
var enumeratorType = getEnumerator.ReturnType;
var enumeratorCurrentType = enumeratorType.GetProperty(nameof(IEnumerator <int> .Current)).PropertyType;
var isEnumeratorByRef = enumeratorCurrentType.IsByRef;
var current = enumeratorType.GetProperty(nameof(IEnumerator <int> .Current)).GetMethod;
var moveNext = enumeratorType.GetMethod(nameof(IEnumerator <int> .MoveNext), BindingFlags.FlattenHierarchy | BindingFlags.Public | BindingFlags.Instance);
if (moveNext == null && enumeratorType.IsGenericType && enumeratorType.GetGenericTypeDefinition() == typeof(IEnumerator <>))
{
moveNext = typeof(IEnumerator).GetMethod(nameof(IEnumerator.MoveNext));
}
using (context.GetLocal(enumeratorType, out var enumerator))
{
context.LoadValue();
il.EmitCall(enumeratorType.IsValueType ? OpCodes.Call : OpCodes.Callvirt, getEnumerator, null);
il.Store(enumerator);
// try
var enumeratorIsDisposable = typeof(IDisposable).IsAssignableFrom(enumeratorType);
if (enumeratorIsDisposable)
{
il.BeginExceptionBlock();
}
// iterate over values
var processLbl = il.DefineLabel();
var loadLbl = il.DefineLabel();
var outOfFinally = il.DefineLabel();
il.Emit(OpCodes.Br, loadLbl);
il.MarkLabel(processLbl);
// true, false
if (itemWriter.RequiresAddress & !isEnumeratorByRef)
{
using (context.GetLocal(itemWriter.Type, out var value))
{
il.CallOn(enumerator, current);
il.Store(value);
using (context.OverrideScope(itemWriter, value))
{
consumeValue();
}
}
}
// true, true
// false, false
if (itemWriter.RequiresAddress ^ isEnumeratorByRef == false)
{
void LoadValue()
{
il.CallOn(enumerator, current);
}
using (context.Scope(LoadValue, false))
{
consumeValue();
}
}
// false, true
if (!itemWriter.RequiresAddress & isEnumeratorByRef)
{
void LoadValue()
{
il.CallOn(enumerator, current);
il.LoadIndirect(itemWriter.Type);
}
using (context.Scope(LoadValue, false))
{
consumeValue();
}
}
il.MarkLabel(loadLbl);
il.CallOn(enumerator, moveNext);
il.Emit(OpCodes.Brtrue, processLbl);
if (enumeratorIsDisposable)
{
il.Emit(OpCodes.Leave, outOfFinally);
// finally
il.BeginFinallyBlock();
var nullLbl = il.DefineLabel();
il.Load(enumerator);
il.Emit(OpCodes.Brfalse, nullLbl);
il.Load(enumerator);
il.EmitCall(OpCodes.Callvirt, typeof(IDisposable).GetMethod(nameof(IDisposable.Dispose)), null);
il.MarkLabel(nullLbl);
il.EndExceptionBlock();
il.MarkLabel(outOfFinally);
}
}
}
