Hello all
Reminder: the issue is about renaming "range" as "interval" in the
"org.apache.sis.measure" package [1] for avoiding name clash with the
ISO 19123 (Schema for coverage geometry and functions [2]) concept of range.
I have trouble finding proper class names. We currently have:
* Range - a range of any kind of Comparables (not necessarily numeric).
* NumberRange - a range where Comparables are restricted to Numbers
* MeasurementRange - a NumberRange with a unit of measurement.
The word "Interval" seems a perfect match for the current "NumberRange".
The Wikipedia definition for "interval" [3] describes exactly the
"NumberRange" behaviour: including/excluding endpoints, infinite
endpoints, formatting... Even the discussion about whether infinite
endpoints are inclusive or exclusive matches the NumberRange
implementation choice :-). Problem is: "Interval" seems to be used
exclusively for interval of numbers. For example I could easily find
"character range" and "ordinal range" on Google, but have been unable to
find "character interval" (or the definitions that I found were
something completely different). While I found someone using the words
"Numeric Interval" [4], this usage seems to be rare and do not answer
the question "do non-numeric intervals exist?".
Second problem: I couldn't find how to rename "MeasurementRange".
Apparently, almost everyone on the web use the term "measurement
interval" for another purpose (namely: the time elapsed between two
measurements in a time series). Furthermore many web sites use
"measurement range" for exactly what the "MeasurementRange" class is.
Consequently renaming "MeasurementRange" as "MeasurementInterval" would
probably cause a more severe confusion than the one we are trying to solve.
In summary:
* Renaming "MeasurementRange" to "MeasurementInterval" seems out of
the question.
* Renaming "NumberRange" to "NumericInterval" would be okay.
* Renaming "Range" to "Interval" would be so-so, because "interval"
seems to imply "numeric interval" in the majority of cases.
So I'm tempted to either keep the class names as they stand today
(with "Range" name everywhere) and explain in the javadoc the
relationship with the ISO 19123 concept of "ranges", or either rename
only "NumericRange" as "Interval" and leave all other names unchanged:
* pro:
o Class names "Range", "Interval" and "MeasurementRange" are the
most accurate names I can see for what those classes are.
o On those 3 above classes, "NumberRange" was by far the most
frequently used one, and renaming that class as "Interval" give
him a lovely name which is both short and mathematically accurate.
o In particular, the class used in context of ISO 19123
implementation will be mostly NumberRange, so renaming only that
class as "Interval" may be sufficient for avoiding a name clash
with the ISO 19123 concept of range.
* cons:
o The hierarchy would be "MeasurementRange extends Interval
extends Range". The "Interval" class name would look like a
foreigner in the middle of all those classes using the "Range" word.
Any opinions?
Martin
[1]
https://builds.apache.org/job/sis-jdk7/site/apidocs/org/apache/sis/measure/package-summary.html
[2] http://www.opengeospatial.org/standards/as (topic 6)
[3] http://en.wikipedia.org/wiki/Interval_%28mathematics%29
[4] http://www.gabormelli.com/RKB/Numeric_Interval
