Effect of typeset -U for colon separated paths?

[Hannu Koivisto <azure@iki.fi>]

Greetings,

I have few other colon separated paths in addition to PATH and
MANPATH that need to be managed in a similar fashion.  In PATH's
and MANPATH's case I can avoid duplicates by saying "typeset -U
path manpath" because PATH and MANPATH are special in that they
mirror array parameters path and manpath, respectively.  I couldn't
find any way to establish similar mirroring for arbitrary
variables, though, so I need to get rid of duplicates manually.  I
thought about creating a temporary array, let's call it "foo",
declare its elements unique and then split elements of my colon
separated variables into it and join them back.  Unfortunately I
couldn't get splitting to work.  I tried...

BAR=foo:bar:baz
foo=(${(s:::)BAR}

...but s expansion flag couldn't split with plain ":" (for
understandable reasons).  I couldn't figure out any working way to
quote it either.  How should such splitting be done?  Or are there
alternative, easier ways of getting rid of duplicates in colon
separated paths?

-- 
Hannu
Please don't send copies of list mail