正則表達式來分割上的字符數的字符串，但得到

Question

我目前使用正則表達式來拆分一個字符串轉換爲15個字符子全字：

(?<=\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 

我想修改這個有點： 分成15個或更少的字符，但只能分割空白以獲取整個單詞。 如果＃1中的分隔符超過15個字符，則將其拆分。

雖然這可能會變得混亂。如果我有一個長度超過15個字符的單詞，我希望這個單詞被分割，然後下面的子字符串也應該有15個字符，而不僅僅是單詞的後半部分。

對於上面的例子，我想：

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

我也很樂意用：

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

如果前兩個不能在一個單一的正則表達式可以做到，那麼我會很高興與：

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

兩者的區別在於我將長字符串拆分到了不同的位置。

是否有可能用一個正則表達式來做到這一點？

Answer 1

瞭解語言可以更清楚地知道應該使用哪些標記和構造。如果您在使用Ruby 2.0或更高版本則沒這一個：

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

通過以換行符替換\n比賽你會得到你想要的方式將字符串分割：

First second 
third fourth 
fifth 
sixthsixthsixth 
sixthsixthsixth 
sixth seventh 

Live demo

如果你需要他們爲拍攝組陣列只，然後有一個較短的方式：

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

Live demo

說明：

(   # 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