Question

I understand regex broadly but I hoped somebody could help understand this a bit better. I’m using it to insert a double new line where there was only one before- it almost works, but not quite. I stole this from ‘github flavored markdown’ – it modifies to support new lines more intuitively.

 cleaned.gsub!(/^[\w\<][^\n]*\n+/) do |x|
      x =~ /\n{2}/ ? x : (x.strip!; x << "  \n")
 end

Answer 1

/^ – From beginning of the string:

[\w\<] – Match any latter character or Open angle bracket. After that:

[^\n]* – There should be any non-new line characters, and

\n+/ – at the end should be one or many new lines.

So then on every match code replaces with:

If matched code contains two new-lines, then keep it untouched.

Otherwise strip it an add space and new line at the end.