yield_from: implementing yield from func() functionality by modifying yield *func() behavior
Usage
require 'yield_from'
class A
extend YieldFrom
def rec(n)
return to_enum(:rec,n) if !block_given?
return if n<0
yield n
yield *rec(n-1)
end
yield_from :rec
end
p A.new.rec(5).to_a # => [5, 4, 3, 2, 1, 0]
There are instance method version and local function version.
Motivation
In the above example, similar code was running until Ruby 2.7 .
class A
def rec(n)
return to_enum(:rec,n) if !block_given?
return if n<0
yield n
rec(n-1, &proc)
end
end
p A.new.rec(5).to_a # => [5, 4, 3, 2, 1, 0]
The bare proc got forbidden in Ruby 3.0.
You can see the discussion at https://qiita.com/cielavenir/items/0cc9189f2c40d6047d8b .
Acknowledgement
Learned Ruby decorator from Nakayama R et al. Automatic Translation of Decorators from Python to Ruby, The 77th National Convention of IPSJ, 2015