// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include 'src/builtins/builtins-collections-gen.h'

namespace collections {
@export
macro LoadKeyValuePairNoSideEffects(implicit context: Context)(o: JSAny):
    KeyValuePair labels MayHaveSideEffects {
  typeswitch (o) {
    case (a: FastJSArray): {
      const length: Smi = a.length;
      typeswitch (a.elements) {
        case (elements: FixedArray): {
          return KeyValuePair{
            key: length > 0 ? array::LoadElementOrUndefined(elements, 0) :
                              Undefined,
            value: length > 1 ? array::LoadElementOrUndefined(elements, 1) :
                                Undefined
          };
        }
        case (elements: FixedDoubleArray): {
          return KeyValuePair{
            key: length > 0 ? array::LoadElementOrUndefined(elements, 0) :
                              Undefined,
            value: length > 1 ? array::LoadElementOrUndefined(elements, 1) :
                                Undefined
          };
        }
        case (FixedArrayBase): deferred {
          unreachable;
        }
      }
    }
    case (JSReceiver): {
      goto MayHaveSideEffects;
    }
    case (o: JSAny): deferred {
      ThrowTypeError(MessageTemplate::kIteratorValueNotAnObject, o);
    }
  }
}

@export
transitioning macro LoadKeyValuePair(implicit context: Context)(o: JSAny):
    KeyValuePair {
  try {
    return LoadKeyValuePairNoSideEffects(o) otherwise Generic;
  } label Generic {
    return KeyValuePair{
      key: GetProperty(o, Convert<Smi>(0)),
      value: GetProperty(o, Convert<Smi>(1))
    };
  }
}
}