building tsquery directly in memory (avoid makepol)

I know in advance the structure of a whole tsquery, it has already
been reduced and lexemes have been already computed.
I'd like to directly write it in memory without having to pass
through pushValue/makepol.

Anyway I'm not pretty sure about what is the layout of a tsquery in
memory and I still haven't been able to find the MACRO that could
help me [1].

Before doing it the trial and error way can somebody just make me an
example?
I'm not pretty sure about my interpretation of the comments of the
documentation.

This is how I'd write
X:AB | YY:C | ZZZ:D

TSQuery
vl_len_ (total # of bytes of the whole following structure
QueryItems*size + total lexeme length)
size (# of QueryItems in the query)
QueryItem
type QI_OPR
oper OP_OR
left -> distance from QueryItem X:AB
QueryItem
type QI_OPR
oper OP_OR
left -> distance from QueryItem ZZZ:D
QueryItem (X)
type QI_VAL
weight 1100
valcrc ???
lenght 1
distance
QueryItem (YY)
type QI_VAL
weight 0010
valcrc ???
lenght 2
distance
QueryItem (ZZZ)
type QI_VAL
weight 0001
valcrc ???
lenght 3
distance
X
YY
ZZZ

[1] the equivalent of POSTDATALEN, WEP_GETWEIGHT, macro to compute
the size of various parts of TSQuery etc...

I couldn't see any place in the code where TSQuery is built in "one
shot" in spite of using pushValue.

Another thing I'd like to know is: what is going to be preferred
during a scan between
'java:1A,2B '::tsvector @@ to_tsquery('java:A | java:B');
vs.
'java:1A,2B '::tsvector @@ to_tsquery('java:AB')
?
they look equivalent. Are they?

thanks

--
Ivan Sergio Borgonovo
http://www.webthatworks.it