filter for filters

Filter values based on a predicate closure.

Signature

> filter {flags} (closure)

Parameters

  • closure: Predicate closure.

Input/output types:

inputoutput
list<any>list<any>
rangelist<any>

Examples

Filter items of a list according to a condition

> [1 2] | filter {|x| $x > 1}
╭───┬───╮
 0  2 
╰───┴───╯

Filter rows of a table according to a condition

> [{a: 1} {a: 2}] | filter {|x| $x.a > 1}
╭───┬───╮
 # │ a │
├───┼───┤
 0  2 
╰───┴───╯

Filter rows of a table according to a stored condition

> let cond = {|x| $x.a > 1}; [{a: 1} {a: 2}] | filter $cond
╭───┬───╮
 # │ a │
├───┼───┤
 0  2 
╰───┴───╯

Filter items of a range according to a condition

> 9..13 | filter {|el| $el mod 2 != 0}
╭───┬────╮
 0   9 
 1  11 
 2  13 
╰───┴────╯

List all numbers above 3, using an existing closure condition

> let a = {$in > 3}; [1, 2, 5, 6] | filter $a

Notes

This command works similar to 'where' but allows reading the predicate closure from a variable. On the other hand, the "row condition" syntax is not supported.