[xsl] Using XSLT to build an index

["Mark" <mark@xxxxxxxxxxxx>]

The list archives did not seem to contain an XSLT stylesheet that could 
index an XML file, but I may have missed it. Is it practical to write my own 
XSLT 2 indexing stylesheet? If so, I have a bilingual XML file that I want 
to index. My assumptions are that I must get rid of the punctuation 
properly, then isolate the words, sort them, remove stop words, and so on. 
To get started, I need a bit of help. All of the phrases are found in two 
attributes: @czech and @eng.

Three questions:
(1) I am aware from Michaelbs book that regex expressions may be used in the 
replace() function, but I do not know how to write that regex expression. I 
would like to remove all the punctuation from a phrase as follows: for 
everything except a hyphen [-], replacement should be with an empty string; 
the hyphen should be replaced with a single space.

(2) I assume that to get rid of extra spaces (if any), I can use a construct 
like: normalize-space(replace(@czech, bsome regex expressionb)).

(3) I assume that tokenize(normalize-space(replace(@czech, 'some regex 
expression'))) will permit me to write out a list of the words found in 
those attributes to an XML document. I am not completely clear as to what 
tokenize() returns, or how to access that return.

I would appreciate any comments, and especially the construction of the 
regex expression needed.
Thanks,
Mark