24/04/2013 21:41, pdv:
Why do you add 0x61 to the values?
That's just for easy reading when looking at what exactly gets written
to the map; In this way the codes are a, b, c ...
That makes sense.
I do not think there is a need to have a map per document. A shared map
stored in TextLetrics should be OK (like singleWidth currently).
I was worried that the map might grow out of proportion, e.g. when
leaving the application open for a long time and since there are more
words than characters this will be worse than for singleWidth.
I would start with the simple solution and then worry about a more
complicated one. A shared map will take less total memory. If acces time
is bad, then it may be worth implementing qHash(docstring) (by aping the
QString version) and use a QHash<doctring, int>.
When typing it's unavoidable to generate all partials of a word; these
are removed again from the map so that only the final word remains;
However nothing is done to remedy the reverse: when deleting a word
character by character all partials will end-up in the map;
Did you do some measurement to ensure that there is a gain of doing that?
I don't think it makes so much difference in time. It was merely to
avoid filling the map with useless entries, especially if a single map
is used.
My policy in these kind of situation is to implement the simple solution
and do optimization only when some measurement (profiling) proved that
there is a problem to solve. Remember Knuth quote: "Premature
optimization is the root of all evil (or at least most of it) in
programming."
Do not hesitate to post patches as often as needed. While I do not have
time to look at the hard parts of the patch right now, I think we move
in the right direction.
JMarc
