protected override void EmitRead(Compiler.CompilerContext ctx, Compiler.Local valueFrom)
{
using (Compiler.Local oldList = AppendToCollection ? ctx.GetLocalWithValue(ExpectedType, valueFrom) : null)
using (Compiler.Local builder = new Compiler.Local(ctx, builderFactory.ReturnType))
{
ctx.EmitCall(builderFactory);
ctx.StoreValue(builder);
if (AppendToCollection)
{
Compiler.CodeLabel done = ctx.DefineLabel();
if (!Helpers.IsValueType(ExpectedType))
{
ctx.LoadValue(oldList);
ctx.BranchIfFalse(done, false); // old value null; nothing to add
}
#if COREFX
TypeInfo typeInfo = ExpectedType.GetTypeInfo();
#else
Type typeInfo = ExpectedType;
#endif
PropertyInfo prop = Helpers.GetProperty(typeInfo, "Length", false);
if (prop == null)
{
prop = Helpers.GetProperty(typeInfo, "Count", false);
}
#if !NO_GENERICS
if (prop == null)
{
prop = Helpers.GetProperty(ResolveIReadOnlyCollection(ExpectedType, Tail.ExpectedType), "Count", false);
}
#endif
ctx.LoadAddress(oldList, oldList.Type);
ctx.EmitCall(Helpers.GetGetMethod(prop, false, false));
ctx.BranchIfFalse(done, false); // old list is empty; nothing to add
Type voidType = ctx.MapType(typeof(void));
if (addRange != null)
{
ctx.LoadValue(builder);
ctx.LoadValue(oldList);
ctx.EmitCall(addRange);
if (addRange.ReturnType != null && add.ReturnType != voidType)
{
ctx.DiscardValue();
}
}
else
{
// loop and call Add repeatedly
MethodInfo moveNext, current, getEnumerator = GetEnumeratorInfo(ctx.Model, out moveNext, out current);
Helpers.DebugAssert(moveNext != null);
Helpers.DebugAssert(current != null);
Helpers.DebugAssert(getEnumerator != null);
Type enumeratorType = getEnumerator.ReturnType;
using (Compiler.Local iter = new Compiler.Local(ctx, enumeratorType))
{
ctx.LoadAddress(oldList, ExpectedType);
ctx.EmitCall(getEnumerator);
ctx.StoreValue(iter);
using (ctx.Using(iter))
{
Compiler.CodeLabel body = ctx.DefineLabel(), next = ctx.DefineLabel();
ctx.Branch(next, false);
ctx.MarkLabel(body);
ctx.LoadAddress(builder, builder.Type);
ctx.LoadAddress(iter, enumeratorType);
ctx.EmitCall(current);
ctx.EmitCall(add);
if (add.ReturnType != null && add.ReturnType != voidType)
{
ctx.DiscardValue();
}
ctx.MarkLabel(@next);
ctx.LoadAddress(iter, enumeratorType);
ctx.EmitCall(moveNext);
ctx.BranchIfTrue(body, false);
}
}
}
ctx.MarkLabel(done);
}
EmitReadList(ctx, builder, Tail, add, packedWireType, false);
ctx.LoadAddress(builder, builder.Type);
ctx.EmitCall(finish);
if (ExpectedType != finish.ReturnType)
{
ctx.Cast(ExpectedType);
}
}
}
MethodInfo GetEnumeratorInfo(TypeModel model, out MethodInfo moveNext, out MethodInfo current)
{
#if WINRT
TypeInfo enumeratorType = null, iteratorType, expectedType = ExpectedType.GetTypeInfo();
#else
Type enumeratorType = null, iteratorType, expectedType = ExpectedType;
#endif
// try a custom enumerator
MethodInfo getEnumerator = Helpers.GetInstanceMethod(expectedType, "GetEnumerator", null);
Type itemType = Tail.ExpectedType;
if (getEnumerator != null)
{
iteratorType = getEnumerator.ReturnType
#if WINRT
.GetTypeInfo()
#endif
;
moveNext = Helpers.GetInstanceMethod(iteratorType, "MoveNext", null);
PropertyInfo prop = Helpers.GetProperty(iteratorType, "Current", false);
current = prop == null ? null : Helpers.GetGetMethod(prop, false, false);
if (moveNext == null && (model.MapType(ienumeratorType).IsAssignableFrom(iteratorType)))
{
moveNext = Helpers.GetInstanceMethod(model.MapType(ienumeratorType), "MoveNext", null);
}
// fully typed
if (moveNext != null && moveNext.ReturnType == model.MapType(typeof(bool)) &&
current != null && current.ReturnType == itemType)
{
return(getEnumerator);
}
moveNext = current = getEnumerator = null;
}
#if !NO_GENERICS
// try IEnumerable<T>
Type tmp = model.MapType(typeof(System.Collections.Generic.IEnumerable <>), false);
if (tmp != null)
{
tmp = tmp.MakeGenericType(itemType);
#if WINRT
enumeratorType = tmp.GetTypeInfo();
#else
enumeratorType = tmp;
#endif
}
;
if (enumeratorType != null && enumeratorType.IsAssignableFrom(expectedType))
{
getEnumerator = Helpers.GetInstanceMethod(enumeratorType, "GetEnumerator");
#if WINRT
iteratorType = getEnumerator.ReturnType.GetTypeInfo();
#else
iteratorType = getEnumerator.ReturnType;
#endif
moveNext = Helpers.GetInstanceMethod(model.MapType(ienumeratorType), "MoveNext");
current = Helpers.GetGetMethod(Helpers.GetProperty(iteratorType, "Current", false), false, false);
return(getEnumerator);
}
#endif
// give up and fall-back to non-generic IEnumerable
enumeratorType = model.MapType(ienumerableType);
getEnumerator = Helpers.GetInstanceMethod(enumeratorType, "GetEnumerator");
iteratorType = getEnumerator.ReturnType
#if WINRT
.GetTypeInfo()
#endif
;
moveNext = Helpers.GetInstanceMethod(iteratorType, "MoveNext");
current = Helpers.GetGetMethod(Helpers.GetProperty(iteratorType, "Current", false), false, false);
return(getEnumerator);
}