par-each for filters

Run a closure on each row of the input list in parallel, creating a new list with the results.

Signature

> par-each (closure) --threads

Parameters

• closure: the closure to run
• --threads {int}: the number of threads to use

Examples

Multiplies each number. Note that the list will become arbitrarily disordered.

> [1 2 3] | par-each {|| 2 * $in }

Output can still be sorted afterward

> [foo bar baz] | par-each {|e| $e + '!' } | sort
╭───┬──────╮
│ 0 │ bar! │
│ 1 │ baz! │
│ 2 │ foo! │
╰───┴──────╯

Enumerate and sort-by can be used to reconstruct the original order

> 1..3 | enumerate | par-each {|p| update item ($p.item * 2)} | sort-by item | get item
╭───┬───╮
│ 0 │ 2 │
│ 1 │ 4 │
│ 2 │ 6 │
╰───┴───╯

Iterate over each element, producing a list showing indexes of any 2s

> [1 2 3] | enumerate | par-each { |e| if $e.item == 2 { $"found 2 at ($e.index)!"} }
╭───┬───────────────╮
│ 0 │ found 2 at 1! │
╰───┴───────────────╯