unfolding compressed equivalents

Hi,

I have been struggling with a tricky transformation-problem. Maybe
somebody can help me come up with a good xslt-solution.

THE BACKGROUND:
In dictionary entries, text is very often compressed in order to save
space/paper. But these entries can be very hard to read. When
publishing a bilingual dictionary online, I would like to unfold each
equivalent to all of the equivalents, that are postulated to exist in
it's originally compressed structure.

AN EXAMPLE:
In a Danish-English dictionary, I have this extremely compressed
English equivalent(s):
"[last] Sunday (or Monday or Tuesday) evening (or night) I was at home"

- The use of [square brackets] indicate, that the content can be omitted.
- Alternatives to a word - or to a sequence of words - are shown in
one (parenthesis), separated by the word "or".
- Brackets, parenthesis and or's are of course just presentational.

The data are represented in xml like this:
<equivalent>
    <omittable>last</omittable>
    { }
    <either>Sunday</either>
    <or>Monday</or>
    <or>Tuesday</or>
    { }
    <either>evening</either>
    <or>night</or>
    { I was at home}
</equivalent>

 I have shown the text content on the top level in {curly braces}

The rules about equivalents are (here simplified for the example):
- An either-element must be immediately followed by at least one or-element
- There can be zero, one or several omittable-elements in an equivalent
- There can be zero, one or several either/or-constructions in an equivalent
- The equivalents have mixed content

The xml-schema fragment describing such a compressable equivalent is as follows:
<xs:element name="equivalent">
    <xs:complexType mixed ="true">
        <xs:choice minOccurs="0" macOccurs="unbounded">
            <xs:sequence>
                <xs:element name="either" type="xs:string"/>
                <xs:element name="or" macOccurs="unbounded" type="xs:string"/>
            </xs:sequence>
            <xs:element name="omittable" type="xs:string"/>
        </xs:choice>
    </xs:complexType>
</xs:element>

THE GOAL:
In my online dictionary, I would like to show this same equivalent like this:

1. last Sunday evening I was at home
2. last Sunday night I was at home
3. last Monday evening I was at home
4. last Monday night I was at home
5. last Tuesday evening I was at home
6. last Tuesday night I was at home
7. Sunday evening I was at home
8. Sunday night I was at home
9. Monday evening I was at home
10. Monday night I was at home
11. Tuesday evening I was at home
12. Tuesday night I was at home

The resulting underlying xml should thus look like this:
<equivalent>last Sunday evening I was at home</equivalent>
<equivalent>last Sunday night I was at home</equivalent>
<equivalent>last Monday evening I was at home</equivalent>
<equivalent>last Monday night I was at home</equivalent>
<equivalent>last Tuesday evening I was at home</equivalent>
<equivalent>last Tuesday night I was at home</equivalent>
<equivalent>Sunday evening I was at home</equivalent>
<equivalent>Sunday night I was at home</equivalent>
<equivalent>Monday evening I was at home</equivalent>
<equivalent>Monday night I was at home</equivalent>
<equivalent>Tuesday evening I was at home</equivalent>
<equivalent>Tuesday night I was at home</equivalent>

Can anyone help me through function-calls and recursions? I am using XSLT 2.0.

Best regards,
Marie

PS The example was chosen for it's structural clarity only -
definitely not as an example of lexicographical best-practices

**********
Marie Bilde Rasmussen
Content architect, MA, BSc
Gyldendal Publishers
Copenhagen, Denmark

marie_bilde@xxxxxxxxxxxx
mariebilderas@xxxxxxxxx