What is a <group> in Relax NG?

[Gerben Abbink]

In Relax NG, I understand all other group operators (interleave, choice,
oneOrMore, zeroOrMore, optional), but what is the purpose of <group>? Can
you give an example?

 

[George Bina]

Hi,

The group pattern is equivalent with a sequence in XML Schema, it
contains a set of patterns that should follow one after the other. In
Relax NG groups are generally implicit if you specify one pattern after
the other but you can also make explicit groups using the group
element. When you need that? Imagine you want to define a choice of
either a followed by b or x followed by y. Then you need to write

<choice>
<group>
<element name="a">...</element>
<element name="b">...</element>
</group>
<group>
<element name="x">...</element>
<element name="y">...</element>
</group>
</choice>

Best Regards,
George