SQLite

    /* Initialize the contents of sCtx.aTerm[] for column iCol. */
    sCtx.iCol = iCol;
    sCtx.iTerm = 0;
    rc = fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void *)&sCtx);
    if( rc!=SQLITE_OK ) goto offsets_out;

    /* Retreive the text stored in column iCol. If an SQL NULL is stored 
    ** in column iCol, jump immediately to the next iteration of the loop.
    ** If an OOM occurs while retrieving the data (this can happen if SQLite
    ** needs to transform the data from utf-16 to utf-8), return SQLITE_NOMEM 
    ** to the caller. 
    */
    zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol+1);
    nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol+1);
    if( zDoc==0 ){
      if( sqlite3_column_type(pCsr->pStmt, iCol+1)==SQLITE_NULL ){
        continue;
      }
      rc = SQLITE_NOMEM;
      goto offsets_out;
    }

    /* Initialize a tokenizer iterator to iterate through column iCol. */
    rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
    if( rc!=SQLITE_OK ) goto offsets_out;
    pC->pTokenizer = pTab->pTokenizer;

    rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
    while( rc==SQLITE_OK ){
      int i;                      /* Used to loop through terms */

} {{1 0 5 7 1 0 30 7}}
read_test  1.7.1.6 { 
  SELECT offsets(mail) FROM mail WHERE mail MATCH '"serious mail"'
} {{1 0 28 7 1 1 36 4}}

ddl_test   1.7.2.1 { CREATE VIRTUAL TABLE text USING fts3() }

write_test 1.7.2.2 text_content {
  INSERT INTO text VALUES('
    During 30 Nov-1 Dec, 2-3oC drops. Cool in the upper portion, minimum temperature 14-16oC and cool elsewhere, minimum temperature 17-20oC. Cold to very cold on mountaintops, minimum temperature 6-12oC. Northeasterly winds 15-30 km/hr. After that, temperature increases. Northeasterly winds 15-30 km/hr.
  ');
}

read_test  1.7.2.3 {
  SELECT snippet(text) FROM text WHERE text MATCH 'cold'
} {{<b>...</b>cool elsewhere, minimum temperature 17-20oC. <b>Cold</b> to very <b>cold</b> on mountaintops, minimum temperature 6<b>...</b>}}

read_test  1.7.2.4 {
  SELECT snippet(text, '[', ']', '...') FROM text WHERE text MATCH '"min* tem*"'
} {{...the upper portion, [minimum] [temperature] 14-16oC and cool elsewhere, [minimum] [temperature] 17-20oC. Cold...}}

##########################################################################
# Test the example in section 5 (custom tokenizers).
#
ddl_test   1.8.1.1 { CREATE VIRTUAL TABLE simple USING fts3(tokenize=simple) } 
write_test 1.8.1.2 simple_content { 
  INSERT INTO simple VALUES('Right now they''re very frustrated')

error_test 2.1.6 {
  SELECT snippet(a) FROM t1 WHERE a MATCH 'one'
} {illegal first argument to snippet}
error_test 2.1.7 {
  SELECT snippet() FROM t1 WHERE a MATCH 'one'
} {unable to use function snippet in the requested context}
error_test 2.1.8 {
  SELECT snippet(a, b, 'A', 'B', 'C', 'D', 'E') FROM t1 WHERE a MATCH 'one'
} {wrong number of arguments to function snippet()}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test the effect of an OOM error while installing the FTS3 module (i.e.
# opening a database handle). This case was not tested by the OOM testing
# of the document examples above.

set DO_MALLOC_TEST 0
ddl_test   5.1 { CREATE VIRTUAL TABLE t5 USING fts3(x) }
write_test 5.2 t5_content {
  INSERT INTO t5 VALUES('In Xanadu did Kubla Khan A stately pleasure-dome decree Where Alph, the sacred river, ran Through caverns measureless to man Down to a sunless sea.  So twice five miles of fertile ground With walls and towers were girdled round : And there were gardens bright with sinuous rills, Where blossomed many an incense-bearing tree ; And here were forests ancient as the hills, Enfolding sunny spots of greenery.');
}
read_test 5.3 { 
  SELECT snippet(t5) FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b>to a sunless sea.  So twice five <b>miles</b> of fertile ground With walls and towers<b>...</b>}}
read_test 5.4 { 
  SELECT snippet(t5, '<i>') FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b>to a sunless sea.  So twice five <i>miles</b> of fertile ground With walls and towers<b>...</b>}}
read_test 5.5 { 
  SELECT snippet(t5, '<i>', '</i>') FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b>to a sunless sea.  So twice five <i>miles</i> of fertile ground With walls and towers<b>...</b>}}
read_test 5.6 { 
  SELECT snippet(t5, '<i>', '</i>', 'XXX') FROM t5 WHERE t5 MATCH 'miles'
} {{XXXto a sunless sea.  So twice five <i>miles</i> of fertile ground With walls and towersXXX}}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test that an empty MATCH expression returns an empty result set. As
# does passing a NULL value as a MATCH expression.
#
set DO_MALLOC_TEST 0