SQLite

const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtaining SQL Values
** METHOD: sqlite3_value
**
** The sqlite3_value_subtype(V) function returns the subtype for
** an application-defined SQL function argument V.  The subtype
** information can be used to pass a limited amount of context from
** one SQL function to another.  Use the [sqlite3_result_subtype()]
** routine to set the subtype for the return value of an SQL function.
**
** SQLite makes no use of subtype itself.  It merely passes the subtype
** from the result of one application-defined function to the input of
** another.
*/
unsigned int sqlite3_value_subtype(sqlite3_value*);

/*
** CAPI3REF: Copy And Free SQL Values
** METHOD: sqlite3_value
**
** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
** is a [protected sqlite3_value] object even if the input is not.

void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);
int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);


/*
** CAPI3REF: Setting The Subtype Of An SQL Function
** METHOD: sqlite3_context
**
** The sqlite3_result_subtype(C,T) function causes the subtype of
** the result from the application-defined function with context C
** to be T.  Only the lower 8 bits of the subtype T are preserved
** in current versions of SQLite; higher order bits are discarded.
** The number of subtype bytes preserved by SQLite might increase
** in future releases of SQLite.
*/
void sqlite3_result_subtype(sqlite3_context*,unsigned int);

/*
** CAPI3REF: Define New Collating Sequences
** METHOD: sqlite3
**
** ^These functions add, remove, or modify a [collation] associated
** with the [database connection] specified as the first argument.
**

    }
  }
  zOut[16] = 0;
  sqlite3_result_text(context, zOut, -1, SQLITE_TRANSIENT);
}

/*
**     test_extract(record, field)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as the first argument. The
** second argument is the index of the field within that record to
** extract and return.
*/
static void test_extract(

    }

    if( mem.szMalloc ) sqlite3DbFree(db, mem.zMalloc);
  }
}

/*
**      test_decode(record)
**
** This function implements an SQL user-function that accepts a blob
** containing a formatted database record as its only argument. It returns
** a tcl list (type SQLITE_TEXT) containing each of the values stored
** in the record.
*/
static void test_decode(

  }

  sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
  Tcl_DecrRefCount(pRet);
}

/*
**       test_zeroblob(N)
**
** The implementation of scalar SQL function "test_zeroblob()". This is
** similar to the built-in zeroblob() function, except that it does not
** check that the integer parameter is within range before passing it
** to sqlite3_result_zeroblob().
*/
static void test_zeroblob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int nZero = sqlite3_value_int(argv[0]);
  sqlite3_result_zeroblob(context, nZero);
}

/*         test_getsubtype(V)
**
** Return the subtype for value V.
*/
static void test_getsubtype(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_result_int(context, (int)sqlite3_value_subtype(argv[0]));
}

/*         test_setsubtype(V, T)
**
** Return the value V with its subtype changed to T
*/
static void test_setsubtype(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_result_value(context, argv[0]);
  sqlite3_result_subtype(context, (unsigned int)sqlite3_value_int(argv[1]));
}

static int registerTestFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     unsigned int eTextRep; /* 1: UTF-16.  0: UTF-8 */
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);

    { "test_eval",             1, SQLITE_UTF8, test_eval},
    { "test_isolation",        2, SQLITE_UTF8, test_isolation},
    { "test_counter",          1, SQLITE_UTF8, counterFunc},
    { "real2hex",              1, SQLITE_UTF8, real2hex},
    { "test_decode",           1, SQLITE_UTF8, test_decode},
    { "test_extract",          2, SQLITE_UTF8, test_extract},
    { "test_zeroblob",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC, test_zeroblob},
    { "test_getsubtype",       1, SQLITE_UTF8, test_getsubtype},
    { "test_setsubtype",       2, SQLITE_UTF8, test_setsubtype},
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }

    int nZero;          /* Used when bit MEM_Zero is set in flags */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */
    RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
    VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
  } u;
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
  u8  eSubtype;       /* Subtype for this value */
  int n;              /* Number of characters in string value, excluding '\0' */
  char *z;            /* String or BLOB value */
  /* ShallowCopy only needs to copy the information above */
  char *zMalloc;      /* Space to hold MEM_Str or MEM_Blob if szMalloc>0 */
  int szMalloc;       /* Size of the zMalloc allocation */
  u32 uTemp;          /* Transient storage for serial_type in OP_MakeRecord */
  sqlite3 *db;        /* The associated database connection */

  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return (int)sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
  return ((Mem*)pVal)->eSubtype;
}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);

void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
}
void sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);
}
void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  pCtx->pOut->eSubtype = eSubtype & 0xff;
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){

# 2015-09-10
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements tests for sqlite3_value_subtype() and
# sqlite3_result_subtype() interfaces.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_execsql_test subtype1-100 {
  SELECT test_getsubtype('hello');
} {0}
do_execsql_test subtype1-110 {
  SELECT test_getsubtype(test_setsubtype('hello',123));
} {123}
do_execsql_test subtype1-120 {
  SELECT typeof(test_setsubtype('hello',123));
} {text}
do_execsql_test subtype1-130 {
  SELECT test_setsubtype('hello',123);
} {hello}

finish_test