RegEx for passing punctuation - regex

Question

I am using:
(.*) CO\s?[\(.*\)|\[.*\]|\{.*\}|''.*''|".*"](.*)
to represent
3M CO 'A'(MINNESOTA MINING AND MANUFACTURING COMPANY).
However, the first Single quotation mark cannot be covered by the regex code. Could you please tell me why?
s/(.*) CO\s?[\(.*\)|\[.*\]|\{.*\}|''.*''|".*"](.*)/$1 CO $2
I expect to get:
3M CO 'A'(MINNESOTA MINING AND MANUFACTURING COMPANY)
but I get
3M CO A'(MINNESOTA MINING AND MANUFACTURING COMPANY)

Answer 1

I'm guessing that here we wish to design an expression and match our inputs, part by part, such as:
(.+?)\s+CO\s+(['"].+?['"])([(\[{]).+?([)\]}])
We have added extra boundaries, which can be reduced, if not desired.
We are having three main capturing groups:
(.+?) # anything before Co;
(['"].+?['"]) # the quotation part; and
([(\[{]).+?([)\]}]) # inside various brackets included those, which we can escape, if required.
RegEx Circuit
jex.im visualizes regular expressions:
DEMO
Demo
This snippet just shows that how the capturing groups work:
const regex = /(.+?)\s+CO\s+(['"].+?['"])([(\[{]).+?([)\]}])/mg;
const str = `3M CO 'A'(MINNESOTA MINING AND MANUFACTURING COMPANY)
3M CO 'A'[MINNESOTA MINING AND MANUFACTURING COMPANY]
3M CO 'A'{MINNESOTA MINING AND MANUFACTURING COMPANY}
3M CO "A"{MINNESOTA MINING AND MANUFACTURING COMPANY}`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
RegEx
If this expression wasn't desired, it can be modified/changed in regex101.com.

Answer 2

Your regex should be expressed to
/(.*)\sCO\s?(\(.+\).*|".+".*|'.+'.*|{.+}.*|\[.+\].*)/
(.*) First capture group will capture starting group ("3M" in your example)
\sCO\s Then looks for a whitespace followed by CO followed by a whitespace
(".+".* etc.) Second capture group that looks for starting quote or bracket followed by at least one character of anything followed by closing quote, then followed by any number of any character
Why Original Regex Didn't Work
In the original regex, [\(.*\)|\[.*\]|\{.*\}|''.*''|".*"] can be simplified into [''.*''] (for the string you provided). I realize that for other strings, you might want to look for (.*) or [.*] or {.*} or ".*", but for the "3M" string, only the [''.*''] is relevant so we'll just look at this.
So [''.*''] just means: match any character in the list inside [], in any order. In this case, there are three unique characters in the list: ', . and * (although you did repeat ' 3 times). So it matched the first '. But since this match is outside your capture group (), this first ' is not included in your capture group response.
So the next match with (.*) matches everything else that comes after the first ' and includes them in the second matching group, i.e. A'(MINNESOTA MINING AND MANUFACTURING COMPANY) without the ' in front.
Does that make sense?
Demo
If you wanted to ensure the format includes 'A' or [A] or "A" or {A} or (A), then this is what you want:
let regex = /(.*)\sCO\s?(\(.+\)|".+".*|'.+'.*|{.+}.*|\[.+\].*)/;
[pattern, match1, match2] = "3M CO 'A'(MINNESOTA MINING AND MANUFACTURING COMPANY)".match(regex);
console.log(match1 + " CO " + match2);
//3M CO 'A'(MINNESOTA MINING AND MANUFACTURING COMPANY)
[pattern, match1, match2] = '3M CO (A)(MINNESOTA MINING AND MANUFACTURING COMPANY)'.match(regex);
console.log(match1 + " CO " + match2);
//3M CO (A)(MINNESOTA MINING AND MANUFACTURING COMPANY)
[pattern, match1, match2] = '3M CO "A"(MINNESOTA MINING AND MANUFACTURING COMPANY)'.match(regex);
console.log(match1 + " CO " + match2);
//3M CO "A"(MINNESOTA MINING AND MANUFACTURING COMPANY)
[pattern, match1, match2] = "3M CO [A](MINNESOTA MINING AND MANUFACTURING COMPANY)".match(regex);
console.log(match1 + " CO " + match2);
//3M CO [A](MINNESOTA MINING AND MANUFACTURING COMPANY)
[pattern, match1, match2] = "3M CO {A}(MINNESOTA MINING AND MANUFACTURING COMPANY)".match(regex);
console.log(match1 + " CO " + match2);
//3M CO {A}(MINNESOTA MINING AND MANUFACTURING COMPANY)

Answer 3

The ' does not match because in the second capturing group because you use a character class which can be written as CO\s?[(.*)|[\]{}'"] and then it will match CO '
So your pattern actually looks like:
(.*) CO\s?[.*()|[\]{}'"](.*)
^ ^ ^
group 1 Char class group 2
What you might do to get those matching in 2 groups is to use:
(.*?)CO\s?((?:(['"]).*?\3|\(.*?\)|\[.*?\]|\{.*?\}).*)
Explanation
(.*?) Capturing group 1, match any char except newline non greedy
CO\s? Match CO and optional whitespace char
( Capturing group 2
(?: Non capturing group, match any of the options
(['"]).*?\3 Match ' or " and use a backreference to what is captured
| Or
\(.*?\) Match (....)
| Or
\[.*?\] Match [....]
| Or
\{.*?\} Match {....}
) Close non capturing group
.* Match any char until the end of the string
) Close group 2
Regex demo
Note that the .*? is non greedy to prevent unnecessary backtracking and over matching.