Ruby Regexp using gsub is there an equivalent to self keyword?

Question

For example say I wanted to take a string and add 1 value to each a-z character. I am looking for something with a similar syntax:

str = 'abc123'
str.gsub(/[a-z]/, self.next!)

Giving an output of: bcd123 I know I could use some code like:

irb(main):075:0> 'abc123'.split('').map{|x| if x =~ /[a-z]/ then x.next! else x = x end }.join
=> "bcd123"

However, this seems to be pretty sloppy and not very efficient. I would figure there is a much neater way to accomplish the same feat.

Thanks in advance.

Answer 1

String#gsub accepts an optional block. The return value of the block is used as a replacement string.

str.gsub(/[a-z]/) { |x| x.next }
# => "bcd123"

Shorter version using &:next syntax:

str.gsub(/[a-z]/, &:next)
# => "bcd123"