used 'Enumerator#with_index' to detect lineno.

[fumihumi]

used 'Enumerator#with_index' to detect lineno.

before: Defined a variable called lineno to count up for each loop.
after: Fixed it.' Enumerator#with_index'.

Rouge::Formatters is often referenced by developers when creating Custom Formatters, so I think it should be written in a better Ruby way.

and fix block scope variable name.(Adjusted variable names to match those used in other files.)

[jneen]

+1 from me. @fumihumi which version of Ruby added this method?

[pyrmont]

@jneen The method that accepts an index was added in 1.9.2, I think (source).

[fumihumi]

@jneen cc @pyrmont
Thanks for replying.

I used https://github.com/akr/all-ruby to check it.
According to this, it seems to have been added in ruby-1.8.7. (version 1.8.7 did not support argument-based offsets)
According to this, it seems to have been added in ruby-1.9.2

If you want to run it by hand, you can check it with the following command

$ docker run --rm -e 'ALL_RUBY_SINCE=ruby-1.8' -e 'ALL_RUBY_SHOW_DUP=yes' rubylang/all-ruby . /all-ruby -e 'a=[11,22,33,44,55].to_enum; a.with_index(1) { |val,index| puts "index: #{index} for #{val}" }'

result: https://gist.github.com/fumihumi/d4966df51852a08b8807ba9ea0dd585b

Thank you!