在单引号之间替换文本

Question

I'm trying to replace some text in an Excel formula using FlexCel, C# and Regex, but single quotes appear to be tricky from the googling I've done.
The string is like this;
"=RIGHT(CELL(\\"filename\\",'C.Whittaker'!$A$1),LEN(CELL(\\"filename\\",'C.Whittaker'!$A$1))-FIND(\\"]\\",CELL(\\"filename\\",'C.Whittaker'!$A$1)))"

I want to replace C.Whittaker with another name. It's always going to be First Initial . Last Name and it's always going to be inside single quotes.

I've got this regex matching; (?:')[^\\"]+(?:')
I thought the (?:') means that regex matches it, but then ignores it for a replace, yet this doesn't seem to be the case. Suspect the issue is to do with how strings are handled, but it's a bit beyond me.

Answer 1

(?:...) is a non-capturing group; it doesn't capture what it matches (that is, it doesn't make that part of the string available later by means of a backreference), but it does consume it. What you're thinking of is lookarounds, which don't consume what they match.

(?<=')[^']+(?=')

But do you really need them? You might find it simpler to consume the quotes and then add them to the replacement string. In other words, replace '[^']+' with 'X.Newname' .

Answer 2

I believe you need to escape your character you want Regex to take it literally...

ie: (?:') becomes (?:\\')

Answer 3

Do you really need to use regex? Regex is good for complex cases where speed is important, but it leads to difficult to maintain code.

Try this instead:

var formula2 =
    String.Join("'", formula
        .Split(new [] { '\'' })
        .Select((x, n) => n % 2 == 1 ? "new name here" : x));