public static object RelationalMetamethod(Context context, ExprType op, object left, object right)
{
if (left.GetType() != right.GetType())
{
return(false);
}
// There are no metamethods for 'a > b' and 'a >= b' so they are translated to 'b < a' and 'b <= a' respectively
var invert = op == ExprType.GreaterThan || op == ExprType.GreaterThanOrEqual;
var metamethod = GetRelationalMetamethod(context, op, left, right);
if (metamethod != null)
{
if (invert)
{
Context.DynamicCache.GetDynamicCall2()(metamethod, right, left);
}
else
{
Context.DynamicCache.GetDynamicCall2()(metamethod, left, right);
}
}
// In the absence of a '<=' metamethod, try '<', 'a <= b' is translated to 'not (b < a)'
if (op != ExprType.LessThanOrEqual && op != ExprType.GreaterThanOrEqual)
{
return(false);
}
metamethod = GetRelationalMetamethod(context, ExprType.LessThan, left, right);
if (metamethod != null)
{
if (invert)
{
Not(Context.DynamicCache.GetDynamicCall2()(metamethod, right, left));
}
else
{
Not(Context.DynamicCache.GetDynamicCall2()(metamethod, left, right));
}
}
var leftTypeName = BaseLibrary.Type(left);
var rightTypeName = BaseLibrary.Type(right);
if (leftTypeName == rightTypeName)
{
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_TWO_ERROR, "compare", leftTypeName);
}
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_WITH_ERROR, "compare", leftTypeName, rightTypeName);
}
public static object ConcatMetamethod(Context context, object left, object right)
{
var metamethod = GetMetamethod(context, left, Constant.CONCAT_METAMETHOD) ??
GetMetamethod(context, right, Constant.CONCAT_METAMETHOD);
if (metamethod != null)
{
return(Context.DynamicCache.GetDynamicCall2()(metamethod, left, right));
}
var typeName = left is string?BaseLibrary.Type(left) : BaseLibrary.Type(right);
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "concatenate", typeName);
}
public static object CallMetamethod(Context context, object obj, object[] args)
{
var metamethod = GetMetamethod(context, obj, Constant.CALL_METAMETHOD);
if (metamethod != null)
{
var array = new object[args.Length + 1];
array[0] = obj;
Array.Copy(args, 0, array, 1, args.Length);
return(Context.DynamicCache.GetDynamicCall1()(metamethod, new Varargs(array)));
}
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "call", BaseLibrary.Type(obj));
}
public static object NumericMetamethod(Context context, ExprType op, object left, object right)
{
var methodName = GetMethodName(op);
var metamethod = GetMetamethod(context, left, methodName) ?? GetMetamethod(context, right, methodName);
if (metamethod != null)
{
return(Context.DynamicCache.GetDynamicCall2()(metamethod, left, right));
}
var typeName = BaseLibrary.Type(BaseLibrary.ToNumber(left) == null ? left : right);
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "perform arithmetic on", typeName);
}
public static object NewIndexMetamethod(Context context, object obj, object key, object value)
{
var metamethod = GetMetamethod(context, obj, Constant.NEWINDEX_METAMETHOD);
if (metamethod != null)
{
if (metamethod is Delegate)
{
return(Context.DynamicCache.GetDynamicCall3()(metamethod, obj, key, value));
}
if (metamethod is LuaTable)
{
return(Context.DynamicCache.GetDynamicNewIndex()(obj, key, value));
}
}
if (obj is LuaTable)
{
return(null);
}
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "index", BaseLibrary.Type(obj));
}
public static object UnaryMinusMetamethod(Context context, object obj)
{
var metamethod = GetMetamethod(context, obj, Constant.UNARYMINUS_METAMETHOD);
if (metamethod != null)
{
return(Context.DynamicCache.GetDynamicCall1()(metamethod, obj));
}
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "perform arithmetic on", BaseLibrary.Type(obj));
}
public static object LengthMetamethod(Context context, object obj)
{
var metamethod = GetMetamethod(context, obj, Constant.LENGTH_METAMETHOD);
if (metamethod != null)
{
return(Context.DynamicCache.GetDynamicCall1()(metamethod, obj));
}
throw new LuaRuntimeException(ExceptionMessage.OP_TYPE_ERROR, "get length of", BaseLibrary.Type(obj));
}
