[augeas-devel] Re: [PATCH] Add PHP module and associated (basic) test file

[Nate Foster]

> I am pretty confident that switching from taking the union of a lot of
> lenses to a union of strings/regexps will take care of the slowness. The
> difference between 'l(r1) | l(r2) | .. | l(rn)' vs 'l(r1|r2|..|rn)' is
> enormous in terms of the internal processing - when parsing the file,
> the first version requires n regexp matches, whereas the second just
> requires one, plus the regexps for the first version are _much_ bigger
> than for the second.

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 ) ) )

Nate