regex ruby gsub: inserting space between characters in capture group

Question

I am trying to to convert strings like:

"foo(bar baz)bom" => "foo (bar baz) bom"

I have this so far:

"foo(bar baz)bom".gsub(/((\S\()|(\)\S))/,'\1')

But I am not sure what to do with the '\\1' to insert a space between the parens and the character.

Thanks!

Answer 1

Do as below

>> "foo(bar baz)bom".gsub(/[)(]/,"(" =>" (",")" =>") ")
=> "foo (bar baz) bom"
>> 

update

>> "foo (bar baz)bom".gsub(/(?<=\S)\(|\)(?=\S)/,"(" =>" (",")" =>") ")
=> "foo (bar baz) bom"
>> "foo(bar baz)bom".gsub(/(?<=\S)\(|\)(?=\S)/,"(" =>" (",")" =>") ")
=> "foo (bar baz) bom"
>> "foo(bar baz) bom".gsub(/(?<=\S)\(|\)(?=\S)/,"(" =>" (",")" =>") ")
=> "foo (bar baz) bom"
>> 

Answer 2

"foo(bar baz)bom".gsub(/((?<! )\\(|\\)(?! ))/,"(" =>" (",")" =>") ")

会成功的

Answer 3

This is easier:

"foo(bar baz)bom".gsub(/(?<!\s)(?=\()|(?<=\))(?!\s)/, " ")
# => "foo (bar baz) bom"

Answer 4

You were on the right track with \\S\\)|\\)\\S :

"foo(bar baz)bom".gsub /(?=\S\(|\)\S)(.)(.)/, '\1 \2'
#=> "foo (bar baz) bom"

Answer 5

If you don't absolutely have to use gsub, you can do it this way. It's more verbose, but to me it's easier to read than long complex regular expressions:

s = "foo(bar baz)bom"
while s =~ /\w\(/
  s = $` + $&[0] + ' (' + $'
end
while s =~ /\)\w/
  s = $` + ') ' + $&[1] + $'
end

Like I say, it's verbose. But it's straightforward and there's no guesswork.

Of course you can replace

$` + $&[0] + ' (' + $'

with

"#{$`}#{$&[0]} (#{$'}"

if you prefer to use string interpolation rather than + or <<. But I think the first form is easier to read.

If you aren't familiar with this notation, $` is the part of the string before the match, $& is the matched string, and $' is the part after the match. It's easy to remember which is which because it's left to right on your keyboard.