operator
children element-qualifier*
An operator that returns the number of subelements of the given element that have occurred thus far in processing.
If an element qualifier is not given, children returns the number of subelements of the current element. If it is used before the current element is processed, it will return zero (0).
If an element qualifier was given, the count of the children processed so far of the indicated element is returned, including the currently open child. Inclusions are counted, as well as proper subelements.
For example, the following do when block uses children as a qualifier. The actions contained by the block (which are not shown in the example) will only be executed when the test occurs in the first child element of the parent:
do when children of parent = 1 ... done