[Pyparsing] pattern type, result type, & naming

[spir <den...@fr...>]

Hello,

New to the list. I'm trying to understand how things work with pattern types, 
result types, and naming through setResultsName() or (). Example:

a	= Literal('a')
b	= Literal('b')
c1	= (a|b)('|    ')
c2	= MatchFirst(a,b)('first')
c3	= (a^b)('^    ')
c4	= Or(a,b)('or   ')
c5	= Combine(a|b)('combi')
c0	= Group(a|b)('group')
patterns = [c1,c2,c3,c4,c5,c0]
t = "a"
# === use
for p in patterns:
	result = p.parseString(t)
	token = result[0]
	print p.resultsName, token.__class__.__name__, token,
	try:
		print token.getName()
	except AttributeError:
		print 'no_getName()'
print 'full result: %s' %(result)
# === output
|     str a no_getName()
first str a no_getName()
^     str a no_getName()
or    str a no_getName()
combi str a no_getName()
group ParseResults ['a'] group
full result: [['a']]

This leads me to the following questions ;-)
-1- Why aren't all results of type ParseResults?
-2- Which patterns, actually, generate ParseResults results, and which don't?
-3- Is there another way to access resultsName, from a result instance, than 
getName()?
-4- Is there another way to guess a result's "kind" (i.e. which pattern has 
generated it)?
-5- Do we need to systematically Group results to identify them?
I wish to get rid of Group where useless, in order not to get results such as 
[['a']] (['a'] is enough overload).

Denis