[augeas-devel] Typechecker optimization

[David Lutterkort]

On Sat, 2008-07-26 at 12:52 -0400, Nate Foster wrote:
> A trick we do in Boomerang, which may be useful if you really do need
> a lens union and can't push it down into a union of regexps, is to
> parse
> 
> (l1 | l2 | l3 | l4)
> 
> as
> 
> ( ( l1 | l2 ) | ( l3 | l4 ) )
> 
> instead of
> 
> ( l1 | ( l2 | ( l3 | l4 ) ) )

How much of a speedup did you see with Boomerang from doing this ? I
just tried that, and the performance improvement is underwhelming ...
runtimes for the typechecker vary by less than 10% between balanced and
unbalanced trees for union/concat, unfortunately the variation goes
either way, i.e. it speeds the typechecker up in some instances and
slows it down in others.

David