使用Ruby从文本中删除硬换行符

Question

我有一些带有强硬换行符的文字,如下所示:

This should all be on one line 
since it's one sentence.

This is a new paragraph that
should be separate.

我想删除单个换行符,但保留双换行符,如下所示:

This should all be on one line since it's one sentence.

This is a new paragraph that should be separate.

有没有一个正则表达式来做到这一点？(或一些简单的方法)

到目前为止,这是我唯一有效的解决方案,但却感觉很自负.

txt = txt.gsub(/(\r\n|\n|\r)/,'[[[NEWLINE]]]')
txt = txt.gsub('[[[NEWLINE]]][[[NEWLINE]]]', "\n\n")
txt = txt.gsub('[[[NEWLINE]]]', " ")

Answer 1

替换所有未在换行符之后或之前的换行符:

text = <<END
This should all be on one line
since it's one sentence.

This is a new paragraph that
should be separate.
END

p text.gsub /(?<!\n)\n(?!\n)/, ' '
#=> "This should all be on one line since it's one sentence.\n\nThis is a new paragraph that should be separate. "

或者,对于没有外观的Ruby 1.8:

txt.gsub! /([^\n])\n([^\n])/, '\1 \2'