SQLite

  }
}

/* A single term in a query is represented by an instances of
** the following structure.
*/
typedef struct QueryTerm {
  short int nPhrase; /* How many following terms are part of the same phrase */
  short int iColumn; /* Column of the index that must match this term */
  signed char isOr;  /* this term is preceded by "OR" */
  signed char isNot; /* this term is preceded by "-" */
  char *pTerm;       /* text of the term.  '\000' terminated.  malloced */
  int nTerm;         /* Number of bytes in pTerm[] */
} QueryTerm;


/* Return a DocList corresponding to the query term *pTerm.  If *pTerm
** is the first term of a phrase query, go ahead and evaluate the phrase

 * A NOT term cannot be the right-hand operand of an OR.  If this
 * occurs in the query string, the NOT is ignored:
 *
 *    [one OR -two]          ==>    one OR two
 *
 */
typedef struct Query {
  fulltext_vtab *pFts;  /* The full text index */
  int nTerms;           /* Number of terms in the query */
  QueryTerm *pTerms;    /* Array of terms.  Space obtained from malloc() */
  int nextIsOr;         /* Set the isOr flag on the next inserted term */
  int iColumn;          /* Text word parsed must be in this column */
} Query;

/* Add a new term pTerm[0..nTerm-1] to the query *q.
*/
static void queryAdd(Query *q, const char *pTerm, int nTerm){
  QueryTerm *t;
  ++q->nTerms;
  q->pTerms = realloc(q->pTerms, q->nTerms * sizeof(q->pTerms[0]));
  if( q->pTerms==0 ){
    q->nTerms = 0;
    return;
  }
  t = &q->pTerms[q->nTerms - 1];
  memset(t, 0, sizeof(*t));
  t->pTerm = malloc(nTerm+1);
  memcpy(t->pTerm, pTerm, nTerm);
  t->pTerm[nTerm] = 0;
  t->nTerm = nTerm;
  t->isOr = q->nextIsOr;
  q->nextIsOr = 0;
  t->iColumn = q->iColumn;
  q->iColumn = -1;
}

/* Free all of the memory that was malloced in order to build *q.
*/
static void queryDestroy(Query *q){
  int i;
  for(i = 0; i < q->nTerms; ++i){
    free(q->pTerms[i].pTerm);
  }
  free(q->pTerms);
}

/*
** Check to see if the string zToken[0...nToken-1] matches any
** column name in the virtual table.   If it does,
** return the zero-indexed column number.  If not, return -1.
*/
static int checkColumnSpecifier(
  fulltext_vtab *pVtab,    /* The virtual table */
  const char *zToken,      /* Text of the token */
  int nToken               /* Number of characters in the token */
){
  int i;
  for(i=0; i<pVtab->nColumn; i++){
    if( memcmp(pVtab->azColumn[i], zToken, nToken)==0
        && pVtab->azColumn[i][nToken]==0 ){
      return i;
    }
  }
  return -1;
}

/*
** Parse the text at pSegment[0..nSegment-1].  Add additional terms
** to the query being assemblied in pQuery.
**
** inPhrase is true if pSegment[0..nSegement-1] is contained within
** double-quotes.  If inPhrase is true, then the first term
** is marked with the number of terms in the phrase less one and
** OR and "-" syntax is ignored.  If inPhrase is false, then every
** term found is marked with nPhrase=0 and OR and "-" syntax is significant.
*/
static int tokenizeSegment(
  sqlite3_tokenizer *pTokenizer,          /* The tokenizer to use */
  const char *pSegment, int nSegment,     /* Query expression being parsed */
  int inPhrase,                           /* True if within "..." */
  Query *pQuery                           /* Append results here */
){
  const sqlite3_tokenizer_module *pModule = pTokenizer->pModule;
  sqlite3_tokenizer_cursor *pCursor;
  int firstIndex = pQuery->nTerms;
  int iCol;
  
  int rc = pModule->xOpen(pTokenizer, pSegment, nSegment, &pCursor);
  if( rc!=SQLITE_OK ) return rc;
  pCursor->pTokenizer = pTokenizer;

  while( 1 ){
    const char *pToken;
    int nToken, iBegin, iEnd, iPos;

    rc = pModule->xNext(pCursor,
                        &pToken, &nToken,
                        &iBegin, &iEnd, &iPos);
    if( rc!=SQLITE_OK ) break;
    if( !inPhrase &&
        pSegment[iEnd]==':' &&
         (iCol = checkColumnSpecifier(pQuery->pFts, pToken, nToken))>=0 ){
      pQuery->iColumn = iCol;
      continue;
    }
    if( !inPhrase && pQuery->nTerms>0 && nToken==2
         && pSegment[iBegin]=='O' && pSegment[iBegin+1]=='R' ){
      pQuery->nextIsOr = 1;
      continue;
    }
    queryAdd(pQuery, pToken, nToken);
    if( !inPhrase && iBegin>0 && pSegment[iBegin-1]=='-' ){

                      Query *pQuery){
  int iInput, inPhrase = 0;

  if( nInput<0 ) nInput = strlen(pInput);
  pQuery->nTerms = 0;
  pQuery->pTerms = NULL;
  pQuery->nextIsOr = 0;
  pQuery->iColumn = -1;
  pQuery->pFts = v;

  for(iInput=0; iInput<nInput; ++iInput){
    int i;
    for(i=iInput; i<nInput && pInput[i]!='"'; ++i)
      ;
    if( i>iInput ){
      tokenizeSegment(v->pTokenizer, pInput+iInput, i-iInput, inPhrase,

  }
  return SQLITE_OK;
}

/* Perform a full-text query using the search expression in
** pInput[0..nInput-1].  Return a list of matching documents
** in pResult.
**
** Queries must match column iColumn.  Or if iColumn>=nColumn
** they are allowed to match against any column.
*/
static int fulltextQuery(fulltext_vtab *v, int iColumn,
                         const char *pInput, int nInput, DocList **pResult){
  Query q;
  int i, rc;
  DocList *pLeft = NULL;
  DocList *pRight, *pNew;
  int nNot = 0;
  int iCol;

  rc = parseQuery(v, pInput, nInput, &q);
  if( rc!=SQLITE_OK ) return rc;

  /* Merge AND terms. */
  for(i = 0 ; i < q.nTerms; i += q.pTerms[i].nPhrase + 1){

    if( q.pTerms[i].isNot ){
      /* Handle all NOT terms in a separate pass */
      nNot++;
      continue;
    }

    iCol = q.pTerms[i].iColumn;
    if( iCol<0 ) iCol = iColumn;
    rc = docListOfTerm(v, iCol, &q.pTerms[i], &pRight);
    if( rc ){
      queryDestroy(&q);
      return rc;
    }
    if( pLeft==0 ){
      pLeft = pRight;
    }else{

    /* We do not yet know how to handle a query of only NOT terms */
    return SQLITE_ERROR;
  }

  /* Do the EXCEPT terms */
  for(i=0; i<q.nTerms;  i += q.pTerms[i].nPhrase + 1){
    if( !q.pTerms[i].isNot ) continue;
    iCol = q.pTerms[i].iColumn;
    if( iCol<0 ) iCol = iColumn;
    rc = docListOfTerm(v, iCol, &q.pTerms[i], &pRight);
    if( rc ){
      queryDestroy(&q);
      docListDelete(pLeft);
      return rc;
    }
    pNew = docListNew(DL_DOCIDS);
    docListExceptMerge(pLeft, pRight, pNew);

# 2006 September 13
#
# 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 regression tests for SQLite library.  The
# focus of this script is testing the FTS1 module.
#
# $Id: fts1b.test,v 1.3 2006/09/13 16:02:44 drh Exp $
#

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

# If SQLITE_ENABLE_FTS1 is defined, omit this file.
ifcapable !fts1 {

do_test fts1b-2.1 {
  execsql {
    CREATE VIRTUAL TABLE t2 USING fts1(from,to);
    INSERT INTO t2([from],[to]) VALUES ('one two three', 'four five six');
    SELECT [from], [to] FROM t2
  }
} {{one two three} {four five six}}


# Compute an SQL string that contains the words one, two, three,... to
# describe bits set in the value $i.  Only the lower 5 bits are examined.
#
proc wordset {i} {
  set x {}
  for {set j 0; set k 1} {$j<5} {incr j; incr k $k} {
    if {$k&$i} {lappend x [lindex {one two three four five} $j]}
  }
  return '$x'
}

# Create a new FTS table with three columns:
#
#    norm:      words for the bits of rowid
#    plusone:   words for the bits of rowid+1
#    invert:    words for the bits of ~rowid
#
db eval {
   CREATE VIRTUAL TABLE t4 USING fts1([norm],'plusone',"invert");
}
for {set i 1} {$i<=15} {incr i} {
  set vset [list [wordset $i] [wordset [expr {$i+1}]] [wordset [expr {~$i}]]]
  db eval "INSERT INTO t4(norm,plusone,invert) VALUES([join $vset ,]);"
}

do_test fts1b-4.1 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'norm:one'}
} {1 3 5 7 9 11 13 15}
do_test fts1b-4.2 {
  execsql {SELECT rowid FROM t4 WHERE norm MATCH 'one'}
} {1 3 5 7 9 11 13 15}
do_test fts1b-4.3 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'one'}
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15}
do_test fts1b-4.4 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'plusone:one'}
} {2 4 6 8 10 12 14}
do_test fts1b-4.5 {
  execsql {SELECT rowid FROM t4 WHERE plusone MATCH 'one'}
} {2 4 6 8 10 12 14}
do_test fts1b-4.6 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'norm:one plusone:two'}
} {1 5 9 13}
do_test fts1b-4.7 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'norm:one two'}
} {1 3 5 7 9 11 13 15}
do_test fts1b-4.8 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'plusone:two norm:one'}
} {1 5 9 13}
do_test fts1b-4.9 {
  execsql {SELECT rowid FROM t4 WHERE _all MATCH 'two norm:one'}
} {1 3 5 7 9 11 13 15}


finish_test