ruby - 我怎样才能 gsub 直到下一个空行？

Question

给定这个字符串：

bc.  some text
 more text
 even more

^ above here is the empty line

我希望它是：

<pre>
some text
more text
even more
</pre>

^ above here is the empty line

如何正则表达式“从bc.第一个空行开始”？

到目前为止，我得到了这个：

# note that for some reason a direct .gsub! behaves
# differently/fails when using the block, so I use .gsub
textile_markup = textile_markup.gsub(/^bc.  .*^$/m) { |s| "<pre>#{s[5..(s.length)]}</pre>" }

可以理解，这匹配贪婪，直到最后一个空行 - 而不是第一个空行。 如何使 ^$ 部分不贪婪？

Answer 1

str = 
"bc.  some text
more text
even more

^ above here is the empty line

bc.  some text
more text
even more

^ above here is the empty line"

puts str.gsub(/^bc\.  (.*?)\n\n/m, "<pre>\n\\1\n</pre>\n\n")

输出：

<pre>
some text
more text
even more
</pre>

^ above here is the empty line

<pre>
some text
more text
even more
</pre>

^ above here is the empty line

解释

?in.*?使星号算子不贪心

/m最后修饰符使点匹配换行符

Answer 2

可以一口气完成，但需要一些准备：

txt = <<DOC
bc.  some text
 more text
 even more

bc.  some text
 more text
 even more

DOC

TRANSFORMS = {"bc.  " => "<pre>\n",       # The 'bc.  should become <pre> followed by a line-end
              /^ /    => "",              # leading space should be eliminated
             "\n\n"   => "\n<\/pre>\n\n"} # empty line should be preceded by a closing pre-tag

re = Regexp.union(TRANSFORMS.keys)
puts txt.gsub(re, TRANSFORMS)

输出：

<pre>
some text
more text
even more
</pre>

<pre>
some text
more text
even more
</pre>