正则表达式JS。 每个点的新行，但仅在引号之外

Question

This is very strong for me. I give up, after two days, I ask you

Turn this

var str = 'The quick "brown. fox". jumps over. "the lazy dog"'
var str2 = 'The quick «brown. fox». jumps over. «the lazy dog»'

Into this

The quick "brown. fox".
jumps over.
"the lazy dog"

or

The quick «brown. fox». 
jumps over. 
«the lazy dog»

In other words I would like to wrap every dot, but this should not happen if the dot is inside a quote

Thanks

Answer 1

You can use this lookahead based regex:

var re = /(?=(([^"]*"){2})*[^"]*$)\./g;
var r;

r = str.replace(/(?=(([^"]*"){2})*[^"]*$)\./g, '.\n');
 The quick "brown. fox".
 jumps over.
 "the lazy dog"

r = str2.replace(re, '.\n');
 The quick «brown.
 fox».
 jumps over.
 «the lazy dog»

(?=(([^"]*"){2})*[^"]*$) is a lookahead that makes sure there are even number of quotes following dot thus making sure dot is outside the quotes. However note that quotes should be balanced and unescaped.

Answer 2

Another aproach (like in JavaScript : Find (and Replace) text that is NOT in a specific HTML element? ), this could be solved by matching both, the quoted string and the desired period.

In the replace-function you then have the chance to change only the single periods...

txt.replace(/("[^"]*"|«[^»]*»)|(\.)/g, function (_, quoted, dot) {
    if (quoted) return quoted;
    return '.\n';
});

Answer 3

With match

str.match(/((?:"[^"]*"|«[^»]+»|[^".«]+)+(?:\.|$))\s*/g).join("\n")

"The quick "brown. fox". 
jumps over. 
"the lazy dog""

str2.match(/((?:"[^"]*"|«[^»]+»|[^".«]+)+(?:\.|$))\s*/g).join("\n")

"The quick «brown. fox». 
jumps over. 
«the lazy dog»"