LRANGE
Syntax
LRANGE key start stop
Time complexity: O(S+N) where S is the distance of start offset from HEAD for small lists, from nearest end (HEAD or TAIL) for large lists; and N is the number of elements in the specified range.
ACL categories: @read, @list, @slow
Returns the specified elements of the list stored at key
.
The offsets start
and stop
are zero-based indexes, with 0
being the first
element of the list (the head of the list), 1
being the next element and so
on.
These offsets can also be negative numbers indicating offsets starting at the
end of the list.
For example, -1
is the last element of the list, -2
the penultimate, and so
on.
Consistency with range functions in various programming languages
Note that if you have a list of numbers from 0 to 100, LRANGE list 0 10
will
return 11 elements, that is, the rightmost item is included.
This may or may not be consistent with behavior of range-related functions
in your programming language of choice (think Ruby's Range.new
, Array#slice
or Python's range()
function).
Out-of-range indexes
Out of range indexes will not produce an error.
If start
is larger than the end of the list, an empty list is returned.
If stop
is larger than the actual end of the list, Dragonfly will treat it like
the last element of the list.
Return
Array reply: list of elements in the specified range.
Examples
dragonfly> RPUSH mylist "one"
(integer) 1
dragonfly> RPUSH mylist "two"
(integer) 2
dragonfly> RPUSH mylist "three"
(integer) 3
dragonfly> LRANGE mylist 0 0
1) "one"
dragonfly> LRANGE mylist -3 2
1) "one"
2) "two"
3) "three"
dragonfly> LRANGE mylist -100 100
1) "one"
2) "two"
3) "three"
dragonfly> LRANGE mylist 5 10