#include <postgres.h>
#include <string.h>
#include <fmgr.h>
#include <executor/executor.h>

PG_FUNCTION_INFO_V1(get_int4_record_val);

Datum get_int4_record_val(PG_FUNCTION_ARGS) {
    TupleTableSlot* t=(TupleTableSlot*)PG_GETARG_POINTER(0);
    text* valName=(text*)PG_GETARG_POINTER(1);
    int32 val;
    bool isnull;

    val=DatumGetInt32(GetAttributeByName(t, VARDATA(valName), &isnull));
    if(isnull)
        PG_RETURN_NULL();
    
    PG_RETURN_INT32(val);
}