JavaScript library implementing basic operations on Ranges.
Range or Interval, according to wiki, is a set of real numbers with the property that any number that lies between two numbers in the set is also included in the set.
PostgreSQL defines the following operators on ranges (intervals):
| Operator | Description | Example | Result |
|---|---|---|---|
| = | equal | int4range(1,5) = '[1,4]'::int4range | t |
| <> | not equal | numrange(1.1,2.2) <> numrange(1.1,2.3) | t |
| < | less than | int4range(1,10) < int4range(2,3) | t |
| greater than | int4range(1,10) > int4range(1,5) | t <= | less than or equal | numrange(1.1,2.2) <= numrange(1.1,2.2) | t = | greater than or equal | numrange(1.1,2.2) >= numrange(1.1,2.0) | t @> | contains range | int4range(2,4) @> int4range(2,3) | t @> | contains element | '[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestamp | t <@ | range is contained by | int4range(2,4) <@ int4range(1,7) | t <@ | element is contained by | 42 <@ int4range(1,7) | f && | overlap (have points in common) | int8range(3,7) && int8range(4,12) | t << | strictly left of | int8range(1,10) << int8range(100,110) | t
| strictly right of | int8range(50,60) >> int8range(20,30) | t &< | does not extend to the right of | int8range(1,20) &< int8range(18,20) | t &> | does not extend to the left of | int8range(7,20) &> int8range(5,10) | t -|- | is adjacent to | numrange(1.1,2.2) -|- numrange(2.2,3.3) | t
- | union | numrange(5,15) + numrange(10,20) | [5,20)
- | intersection | int8range(5,15) * int8range(10,20) | [10,15)
- | difference | int8range(5,15) - int8range(10,20) | [5,10)
At the moment, library development just started with a particular task to perform union and exclusion of ranges. Union is described in the above table. A excluding B leaves out range(s) that are present in A, but not in B.
To be continued. 2015 August 26, Moscow, Russia.