On 23/02/2011 17:50, bearophile wrote:
Bruno Medeiros:
The good news is that I suspect the fields used for
opEquals/opCmp/opHash in any class are unlikely to be fields that are
computed lazily. It's just a guess though, anyone have examples otherwise?
If I have a string type, I'd like to compute its hash value lazily, the first time I need
it. Computing it requires time, it's useful for sets and associative arrays, but being
the string immutable the result doesn't change, so you want to compute it only once. So
only the array of chars is immutable, while the hash is computed lazily and is not
immutable (it 's "lazily immutable").
Bye,
bearophile
(Hum, I was thinking more of the inputs to the functions, the data that
is primarily used to determine the equality/comparison.) But that's a
completely good and valid example nonetheless, in that it would not be
uncommon for opHash to have some values computed lazily.
But what about the other functions, opEquals/opCmp, any examples?
--
Bruno Medeiros - Software Engineer
