On 29 sept. 2012, at 19:53, "Keith OHara" <k-ohara5...@oco.net> wrote:
> On Sat, 29 Sep 2012 10:30:32 -0700, m...@mikesolomon.org > <m...@mikesolomon.org> wrote: > >> >> The way you're using "tentative" is almost exactly how pure properties are >> used in LilyPond. > > Specifically, 'pure-height being the estimated vertical extent before > line-breaking, while 'height is its extent after line-breaking. > > If there are distinct properties to describe the position at different > stages, then each property can be evaluated just once (as HanWen suggested, > and as Mike agreed 100%). > >> >> I think all property look-ups should be pure until one is absolutely certain >> that the property won't change, at which point the unpure value should be >> cached and returned for both pure and unpure queries (impure sounds too >> religious, thus unpure). The pure properties need not always return the >> same value - they can get closer and closer to the unpure as more and more >> information gets determined. > > This is the opposite approach, where some "properties" are not permanent at > all. The word 'tentative' is a better label than 'pure', because pure > functions would always return the same value given the same arguments. > True dat. Someone wanna do a perl one-line replace subbing in tenative for pure and post the patch? :-) Cheers, MS _______________________________________________ lilypond-devel mailing list lilypond-devel@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-devel
