On 12/16/2014 10:44 AM, Ivan Gerasimov wrote:
On 16.12.2014 17:58, roger riggs wrote:
Hi Ivan,
In which package/class do you propose to add the API to get the comparator?
I was thinking of java.text package, though I don't see a specific class in
which the static method could be naturally included.
This kind of Comparator doesn't seem to be common enough to include in such a
base interface as CharSequence.
In java.time, comparators are returned from static methods in an interface.
This allows lambda to be used for the implementation.
For example, ChronoZonedDateTime.timeLineOrder
<https://docs.oracle.com/javase/8/docs/api/java/time/chrono/ChronoZonedDateTime.html#timeLineOrder-->()[1]
For example a static method could be added to CharSequence:
public static int Comparator<CharSequence> alphaNumericComparator() ...
In use it would be CharSequence.alphaNumericComparator().compare("012", "234");
2) Should there be any provision for number strings internal to the string
with leading zeros.
Should "abc-0123-def" be equal to "abc-123-def"?
The strings will be ordered as:
abc-122-def
abc-0122-def
abc-123-def
abc-0123-def
abc-00123-def
abc-0000123-def
abc-124-def
I.e. the strings with the same numeric value will be grouped together, but the
strings with more leading zeros will be put in the order further.
To my eyes the strings with more leading zeros look bigger, that's why I did it
this way :)
By the way, the Microsoft's StrCmpLogicalW() does it in the opposite direction,
i.e. strings with more leading zeros come earlier.
If people find it useful, we can make it configurable.
It's always desired to have a "customizable" approach for numeric order
collation:-)
-Sherman
