正则表达式忽略某些字符之间

Question

Say I have a string:

"ABC+DF" + someVar + exp(A+B)

I would like to match the + signs before and after some var and not match on ones in double quotes or inside an exp().

Is there a regex way to match only the + signs not in quotes or in the exp()?

Update:

You can assume everything inside exp() should be ignored. Maybe that is another way of thinking about it. Anything in between quotes or exp() should be ignored from the regex.

Regex would be used in java String::split method. I am unsure about which platform that would be.

Answer 1

You can use this in Java with replaceAll + split operations:

jshell> String s = "\"ABC+DF\" + someVar + exp(A+B)";
s ==> "\"ABC+DF\" + someVar + exp(A+B)"

jshell> s.replaceAll("(\"[^\"]*\"|exp\\h*\\([^)]*\\))|\\h*\\+\\h*", "$1\0").split("\0+");
$15 ==> String[3] { "\"ABC+DF\"", "someVar", "exp(A+B)" }

• Regex used in replaceAll matches and captures the part we want to ignore in group #1 on left hand side of alternation. It then replaces match with $1\\0 where \\0 is a NUL byte (ASCII: 0).
• Regex used in split just splits on one or more NUL bytes ie \\0 .

RegEx Demo of replaceAll