## Re: [xsl] 99 bottles of beer

 Subject: Re: [xsl] 99 bottles of beer From: Abel Braaksma Date: Mon, 05 Feb 2007 21:10:15 +0100
Andrew Welch wrote:

Nice! However a couple of small problems:

```2 bottles of beer on the wall.
2 bottles of beer.
Take one down, pass it around
1 bottles of beer on the wall.
^^^^^^^```

```1 bottle of beer on the wall.
1 bottle of beer.
Take one down, pass it around
0 bottle of beer on the wall.
^^^^^^^^```

You just need to modify it slightly:

Thanks for the correction. But now we have duplicated logic (the cast + ends-with), which some consider bad programming practice. Here's an update that does not duplicate the logic, removes the nested for (better: it shows a way of shortcutting nested loops with the comma operator), corrects my error and is much less readable (which was not on purpose, btw).

```for \$i in reverse(1 to 99),
\$j in (1 to 3)```

return concat
(\$i - xs:integer(\$j mod 3 = 0),
' bottle',
('s')[not(\$i * 3 - \$j = (1 to 3))],
' of beer',
(' on the wall.',
'.&#10;Take one down, pass it around',
' on the wall.&#10;' )[\$j]

(I like the idea of using the predicate instead of if...then...else)

As a tutorial it suits well for explaining why:

('s')[\$i * 3 - \$j != (1 to 3)]

yields exactly the same result as:

('s')[\$i * 3 - \$j = (1 to 3)]

which is quite counter-intuitive (IIRC, for a '!=' to return false, none from the left must be the same as any from the right; to be true, only one item needs to be unequal. This is not backed up by the example above, but I am sure I am overlooking something. Moreover, I found that (1 to 2) != 10 returns false, and (1,2) != 10 returns true.... I am really missing something here, this must be a faq somewhere :S ).

```Cheers,
-- Abel Braaksma
http://www.nuntia.nl```