ClickHouse/dbms/src/Functions/arrayMap.cpp

41 lines
1.2 KiB
C++

#include <Functions/FunctionArrayMapped.h>
#include <Functions/FunctionFactory.h>
namespace DB
{
/** arrayMap(x1,...,xn -> expression, array1,...,arrayn) - apply the expression to each element of the array (or set of parallel arrays).
*/
struct ArrayMapImpl
{
/// true if the expression (for an overload of f(expression, arrays)) or an array (for f(array)) should be boolean.
static bool needBoolean() { return false; }
/// true if the f(array) overload is unavailable.
static bool needExpression() { return true; }
/// true if the array must be exactly one.
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & /*array_element*/)
{
return std::make_shared<DataTypeArray>(expression_return);
}
static ColumnPtr execute(const ColumnArray & array, ColumnPtr mapped)
{
return ColumnArray::create(mapped->convertToFullColumnIfConst(), array.getOffsetsPtr());
}
};
struct NameArrayMap { static constexpr auto name = "arrayMap"; };
using FunctionArrayMap = FunctionArrayMapped<ArrayMapImpl, NameArrayMap>;
void registerFunctionArrayMap(FunctionFactory & factory)
{
factory.registerFunction<FunctionArrayMap>();
}
}