Feature #17097

Updated by sawa (Tsuyoshi Sawada) about 2 months ago

`min`, `min_by`, `max`, `max_by` return the element that leads to the minimum or the maximum value, but I think it is as, or even more, frequent that we are interested in the minimum or the maximum value itself rather than the element. For example, to get the length of the longest string in an array, we do: 

 %w[aa b cccc dd].max_by(&:length).length # => 4 
 %w[aa b cccc dd].map(&:length).max # => 4 

 I propose to have methods that return the minimum or the maximum value. Temporarily calling them `map_min`, `map_max`, they should work like this: 

 %w[aa b cccc dd].map_max(&:length) # => 4 

 `map_min`, `map_max` are implementation-centered names, so perhaps better, single-worded better names should replace them, just like `yield_self` was replaced by `then`.