// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package com.android.tools.r8.ir.code;

public interface InstructionIterator extends NextUntilIterator<Instruction> {
  /**
   * Replace the current instruction (aka the {@link Instruction} returned by the previous call to
   * {@link #next} with the passed in <code>newInstruction</code>.
   * <p>
   * The current instruction will be completely detached from the instruction stream with uses
   * of its in-values removed.
   * <p>
   * If the current instruction produces an out-value the new instruction must also produce
   * an out-value, and all uses of the current instructions out-value will be replaced by the
   * new instructions out-value.
   * <p>
   * The debug information of the current instruction will be attached to the new instruction.
   *
   * @param newInstruction the instruction to insert instead of the current.
   */
  void replaceCurrentInstruction(Instruction newInstruction);

  /**
   * Adds an instruction. The instruction will be added just before the current
   * cursor position.
   *
   * The instruction will be assigned to the block it is added to.
   *
   * @param instruction The instruction to add.
   */
  void add(Instruction instruction);
}