The string have the following form:
time-(e1,e2,...)-elapsedtime-(e2,...)...
Where time is the time elapsed from previous set of events and (e1,e2,...) a non empty list of simultaneous events.
The function also works on list.
Use str.seqelist to get a single string for a whole list, and as.character.seqelist to get a vector of strings.
str.eseq and as.character.eseq have mainly an internal purpose (they are called by print methods for example).