正则表达式来分割上的字符数的字符串，但得到

Question

我目前使用正则表达式来拆分一个字符串转换为15个字符子全字：

(?<=\G.{15}) 

示例文本： 第一第二第三第四第五sixthsixthsixthsixthsixthsixth第七

分裂成：

[0] => First second th 
[1] => ird fourth fifth 
[2] => sixthsixthsixth 
[3] => sixthsixthsixths 
[4] => ixth seventh 

我想修改这个有点： 分成15个或更少的字符，但只能分割空白以获取整个单词。 如果＃1中的分隔符超过15个字符，则将其拆分。

虽然这可能会变得混乱。如果我有一个长度超过15个字符的单词，我希望这个单词被分割，然后下面的子字符串也应该有15个字符，而不仅仅是单词的后半部分。

对于上面的例子，我想：

[0] => First second 
[1] => third fourth 
[2] => fifth 
[3] => sixthsixthsixth 
[4] => sixthsixthsixth 
[5] => sixth seventh 

我也很乐意用：

[0] => First second 
[1] => third fourth 
[2] => fifth sixthsixt 
[3] => hsixthsixthsixt 
[4] => hsixthsixth 
[5] => seventh 

如果前两个不能在一个单一的正则表达式可以做到，那么我会很高兴与：

[0] => First second 
[1] => third fourth 
[2] => fifth 
[3] => sixthsixthsixth 
[4] => sixthsixthsixth 
[5] => sixth 
[6] => seventh 

两者的区别在于我将长字符串拆分到了不同的位置。

是否有可能用一个正则表达式来做到这一点？

Answer 1

了解语言可以更清楚地知道应该使用哪些标记和构造。如果您在使用Ruby 2.0或更高版本则没这一个：

(.{1,15}\b|.{15})\K(?: +|\B|\Z) 

通过以换行符替换\n比赛你会得到你想要的方式将字符串分割：

First second 
third fourth 
fifth 
sixthsixthsixth 
sixthsixthsixth 
sixth seventh 

Live demo

如果你需要他们为拍摄组阵列只，然后有一个较短的方式：

(.{1,15}\b|.{15}) 

Live demo

说明：

(   # Begin capturing group (1) 
    .{1,15} # Match 15 characters max (greedy) 
    \b  # Till reaching a word boundary 
    |   # Or 
    .{15}  # Match those parts of a long word 
)   # End of (1) 

    \K   # Reset whatever is matched so far 

    (?:   # Begin non-capturing group 
    +  # Match white-spaces 
    |   # Or 
    \B  # A non-word boudanry 
    |   # Or 
    \Z  # End of string 
)   # End of non-capturing group