From: "Peña, Botp" <botp@...>
Date: 2008-12-02T11:00:59+09:00
Subject: Re: Enumerable#select used to return actual values

From: Mike Austin [mailto:"mike[nospam]"@mike-austin.com] 
..
# (1..10).select { |a| a * a if a > 5 }

the difficulty there is that there is no clear separation bw the selection logic and the mapping logic

# Was it ever there, or did I just have a dream about it?  
# It's easy to implement... just wondering.

it's easy in 1.9..


>p (0..10).select_with_map ->(x){x<5}, ->(x){x*x}
[0, 1, 4, 9, 16]

one could also do partitioning if 3rd block is provided (wc catches the else portion)

>p (0..10).select_with_map ->(x){x<5}, ->(x){x*x}, ->(x){x+x}
[[0, 1, 4, 9, 16], [10, 12, 14, 16, 18, 20]]


but still i prefer {|x| x<5} over ->(x){x<5}
or maybe, ->{|x| x<5} over ->(x){x<5}