/// <summary>
/// Converts a <see cref="Code"/> to an <see cref="OpCode"/>, using a module context to look
/// up potential experimental opcodes
/// </summary>
/// <param name="code">The code</param>
/// <param name="context">The module context</param>
/// <returns>A <see cref="OpCode"/> or <c>null</c> if it's invalid</returns>
public static OpCode ToOpCode(this Code code, ModuleContext context)
{
byte hi = (byte)((ushort)code >> 8);
byte lo = (byte)code;
if (hi == 0)
{
return(OpCodes.OneByteOpCodes[lo]);
}
if (hi == 0xFE)
{
return(OpCodes.TwoByteOpCodes[lo]);
}
if (context.GetExperimentalOpCode(hi, lo) is OpCode op)
{
return(op);
}
if (code == Code.UNKNOWN1)
{
return(OpCodes.UNKNOWN1);
}
if (code == Code.UNKNOWN2)
{
return(OpCodes.UNKNOWN2);
}
return(null);
}
/// <summary>
/// Reads the next OpCode from the current position
/// </summary>
OpCode ReadOpCode()
{
var op = reader.ReadByte();
if (op == 0xFE)
{
return(OpCodes.TwoByteOpCodes[reader.ReadByte()]);
}
if (op >= 0xF0 && op <= 0xFB && context is not null && reader.BytesLeft >= 1)
{
if (context.GetExperimentalOpCode(op, reader.ReadByte()) is OpCode opCode)
{
return(opCode);
}
else
{
reader.Position--;
}
}
return(OpCodes.OneByteOpCodes[op]);
}