sorting issue

JohnBampton · February 23rd, 2009, 05:07 AM

I want to sort with xsl the following xml

Code:

<file>
    
        
        <type>2</type>
    
        
        <type>1</type>
    
        <type>2</type>
    
        <type>2</type>
    
        <type>1</type>
    
</file>

into this

Code:

<file>
    
        
        <type>1</type>
    
        
        <type>2</type>
    
        <type>1</type>
    
        <type>2</type>
    
        <type>2</type>
    
</file>

Any ideas

mhkay · February 23rd, 2009, 05:28 AM

That's a bit like saying the input is ABCDE and you want the output to be WHPRZ. Without giving some idea of the algorithmic relationship of the output to the input, it's a non-starter as a requirements statement.

JohnBampton · February 23rd, 2009, 05:36 AM

I just want the output to be ordered 1 2 1 2 1 2 etc for any combination of input 1 and 2's

mhkay · February 23rd, 2009, 06:03 AM

Oh dear, this is going to be hard work. You clearly understand your problem, but you aren't communicating it very well.

(a) What happens if there is something other than a 1 or a 2 in the input?

(b) One possible description of the transformation you have done is as follows: the input follows the grammar (2+ 1+)* - that is, a sequence of groups, each of which is one-or-more 2s followed by one-or-more 1s - and you want to change it so that each group is reordered with the 1s preceding the 2s. Is that an accurate description of your requirement? (It's a wild guess, I could think of many other relationships between your sample input and output)

JohnBampton · February 23rd, 2009, 06:15 AM

Hello Mr Kay

a) there is only every going to be 1 and 2 as inputs

B) the 1 and 2's can come in any order any amount of times ie 21212, 22112, 12212, 11221 etc

and I want reorder it like the following - 1 followed by 2 followed by 1 followed by 2 etc

I appreciate your effort.

Hope this helps

mhkay · February 23rd, 2009, 07:11 AM

>Hope this helps

No, it doesn't.

If the input is 22222222222222212, what should the output be, and why?

JohnBampton · February 23rd, 2009, 07:17 AM

>
If the input is 22222222222222212, what should the output be, and why?

The output would be 1222222222... etc

No matter how many ones or twos, the output order is always 1212

so for 11112 output of 12111
so for 212111 output of 121211

Thanks

mhkay · February 23rd, 2009, 07:26 AM

OK, I'll have one more go. Perhaps your rule is this:

Let the number of 1s in the input be X. Let the number of 2s in the input be Y. If X<=Y, output "12" repeated X times, followed by "2" repeated (Y-X) times. If X>Y, output "12" repeated Y times, followed by "1" repeated (X-Y) times.

If I've guessed wrong again, then I give up.

JohnBampton · February 23rd, 2009, 07:33 AM

Yes that is exactly it.

You finally understand it.

Now how do I do a sort in xsl?

Any ideas?

mhkay · February 23rd, 2009, 08:02 AM

Try this:

<xsl:for-each select="type">
<xsl:sort select="count(preceding-sibling::type[. = current()])" data-type="number"/>
<xsl:sort select="."/>
<xsl:copy-of select="."/>
</xsl:for-each>