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secondo/Algebras/CRel/Operators/BlockEntry.cpp
2026-01-23 17:03:45 +08:00

79 lines
2.1 KiB
C++

/*
----
This file is part of SECONDO.
Copyright (C) 2004, University in Hagen, Department of Computer Science,
Database Systems for New Applications.
SECONDO is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
SECONDO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
----
*/
#include "BlockEntry.h"
#include "AttrArray.h"
#include "LogMsg.h"
#include "OperatorUtils.h"
#include "Symbols.h"
#include "../TypeConstructors/TBlockTC.h"
#include "TypeUtils.h"
using namespace CRelAlgebra;
using namespace CRelAlgebra::Operators;
extern NestedList *nl;
BlockEntry::BlockEntry() :
Operator(info, nullptr, TypeMapping)
{
}
const OperatorInfo BlockEntry::info = OperatorInfo(
"BLOCKENTRY", "ATTRARRAY -> DATA or tblock -> tuple",
"type operator",
"Determines the attribute type of the entries of a (stream of) attribute "
"array or the tuple type of a (stream of) tuple block.",
"Not for use with sos-syntax");
ListExpr BlockEntry::TypeMapping(ListExpr args)
{
if(!nl->HasLength(args, 1))
{
return GetTypeError("Expected one argument.");
}
ListExpr arg = nl->First(args);
if (TBlockTI::Check(arg))
{
return TBlockTI(arg, false).GetTupleTypeExpr();
}
//Either stream or nonstream
arg = GetStreamType(arg, true);
AttrArrayTypeConstructor *constructor = AttrArray::GetTypeConstructor(arg);
if (constructor == nullptr)
{
return GetTypeError(0, "type", "Not (stream) of type tblock or kind "
"ATTRARRAY.");
}
//Return Attribute-Type
return constructor->GetAttributeType(arg, false);
}