SQLite

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
**
** $Id: callback.c,v 1.35 2009/01/31 22:28:49 drh Exp $
*/

#include "sqliteInt.h"

/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the database text encoding of name zName, length nName.

/* During the search for the best function definition, this procedure
** is called to test how well the function passed as the first argument
** matches the request for a function with nArg arguments in a system
** that uses encoding enc. The value returned indicates how well the
** request is matched. A higher value indicates a better match.
**
** The returned value is always between 0 and 6, as follows:
**
** 0: Not a match, or if nArg<0 and the function is has no implementation.
** 1: A variable arguments function that prefers UTF-8 when a UTF-16
**    encoding is requested, or vice versa.
** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
**    requested, or vice versa.
** 3: A variable arguments function using the same text encoding.
** 4: A function with the exact number of arguments requested that
**    prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
** 5: A function with the exact number of arguments requested that
**    prefers UTF-16LE when UTF-16BE is requested, or vice versa.
** 6: An exact match.
**
*/
static int matchQuality(FuncDef *p, int nArg, u8 enc){
  int match = 0;
  if( p->nArg==-1 || p->nArg==nArg 
   || (nArg==-1 && (p->xFunc!=0 || p->xStep!=0))
  ){
    match = 1;
    if( p->nArg==nArg || nArg==-1 ){
      match = 4;
    }
    if( enc==p->iPrefEnc ){
      match += 2;
    }

# 2001 September 15
#
# 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 file is testing built-in functions.
#
# $Id: func.test,v 1.88 2009/01/31 22:28:49 drh Exp $

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

# Create a table to work with.
#
do_test func-0.0 {

  "
} {1 {no such function: nullx_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_12345678a}}
do_test func-26.6 {
  catchsql "
     SELECT nullx_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789a(0);
  "
} {1 {no such function: nullx_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789a}}

do_test func-27.1 {
  catchsql {SELECT coalesce()}
} {1 {wrong number of arguments to function coalesce()}}
do_test func-27.2 {
  catchsql {SELECT coalesce(1)}
} {1 {wrong number of arguments to function coalesce()}}
do_test func-27.3 {
  catchsql {SELECT coalesce(1,2)}
} {0 1}

finish_test