problems with unique modes

[Fergus Henderson]

Zoltan and Andrew,

Two problems:

1.  For unique modes to be useful for things other than I/O,
alias analysis will have to be able to handle the aliasing that
is introduced by uniq_array__lookup.  Andrew's existing
changes to handle definite aliasing will not be sufficient.

2.  We will need to be able to handle is code of the form

	( uniq_array__insert(Array0, Key, Value, Array1) ->
		Array = Array1
	;
		Array = Array0
	)

The current analysis gives up here, because it doesn't have any
way of knowing that uniq_array__insert will not clobber the first
argument before failing.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3         |     -- the last words of T. S. Garp.