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Issue #5663 has been updated by Thomas Sawyer.
In Facets it's called #compact_map, but that's only b/c I thought better of monkey patching #compact itself.
I think it would be a slick feature for #compact to take a block.
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Feature #5663: Combined map/select method
https://bugs.ruby-lang.org/issues/5663
Author: Yehuda Katz
Status: Open
Priority: Normal
Assignee:
Category: lib
Target version: 2.0.0
It is pretty common to want to map over an Enumerable, but only include the elements that match a particular filter. A common idiom is:
enum.map { |i| i + 1 if i.even? }.compact
It is of course also possible to do this with two calls:
enum.select { |i| i.even? }.map { |i| i + 1 }
Both cases are clumsy and require two iterations through the loop. I'd like to propose a combined method:
enum.map_select { |i| i + 1 if i.even? }
The only caveat is that it would be impossible to intentionally return nil here; suggestions welcome. The naming is also a strawman; feel free to propose something better.
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http://bugs.ruby-lang.org/