public static FuncDef OverloadFunction(Context ctx, FuncDef def, int argsLength, Expr expr)
{
// Check to see the left operand is a column in a virtual table
if (C._NEVER(expr == null))
{
return(def);
}
if (expr.OP != TK.COLUMN)
{
return(def);
}
Table table = expr.Table;
if (C._NEVER(table == null))
{
return(def);
}
if ((table.TabFlags & TF.Virtual) == 0)
{
return(def);
}
IVTable ivtable = GetVTable(ctx, table).IVTable;
Debug.Assert(ivtable != null);
Debug.Assert(ivtable.IModule != null);
ITableModule imodule = (ITableModule)ivtable.IModule;
if (imodule.FindFunction == null)
{
return(def);
}
// Call the xFindFunction method on the virtual table implementation to see if the implementation wants to overload this function
string lowerName = def.Name;
RC rc = RC.OK;
Action <FuncContext, int, Mem[]> func = null;
object[] args = null;
if (lowerName != null)
{
lowerName = lowerName.ToLowerInvariant();
rc = imodule.FindFunction(ivtable, argsLength, lowerName, func, args);
C._tagfree(ctx, ref lowerName);
}
if (rc == RC.OK)
{
return(def);
}
// Create a new ephemeral function definition for the overloaded function
FuncDef newFunc = new FuncDef();//: (FuncDef*)_tagalloc(ctx, sizeof(FuncDef) + _strlen30(def->Name) + 1, true);
if (newFunc == null)
{
return(def);
}
newFunc = def._memcpy();
newFunc.Name = def.Name;
newFunc.Func = func;
newFunc.UserData = args;
newFunc.Flags |= FUNC.EPHEM;
return(newFunc);
}
