Conditional regex problem

Question

Dear all, I've a regular expression problem, and I guess I'm missing a point in how the regex actually work.

I've some set of strings that contains methods definitions

• myMethod1()
• myMethod2(argument1 arg1)
• myMethod3(argument1 arg1, argument2 arg2)

but some of them also contains the output type:

• myOtherMethod1() : type1
• myOtherMethod2(argument1 arg1) : type2
• myOtherMethod3(argument1 arg1, argument2 arg2) : whatever

I want to only have inputs like the first ones: take out the output paramaters. I've taken out my regex hat, and I come up with some conditional regex:

(?([:]+)(.+(?=\s:))|(.+))

If I match a ":" character in my string, I take whatever is before the " :", if not I take all. Theoretically this is correct, but it returns the whole line If I change the regex to

(?([:]*)(.+(?=\s:))|(.+))

Then the second type of methods are correctly regexed, but not the first ones (strange..). Can you explain me where is my mistake?

Thank you very much,

Answer 1

There's no need to handle it like this. Just take up to the first right parentheses you encounter:

/^[^)]*\)/

Unless I'm misunderstanding your problem...

Answer 2

I don't know what the problem is with your regex. I'd use a simpler regex and just match against want you want:

^.*\)

This matches a start of line, followed by any character, followed by a ). The fact the there may be text after the ) is irrelevant.

Answer 3

I came up with ^(.*?\)).*$

This matches the start of the string (^), followed by any characters up to (and including) the first close parenthesis (.*? is lazy match any character, so it will match up to the first ) (the \) is required to escape the string). The rest of the line is ignored (.*$) - make you use the multi-line option, else you'll only match the first part. The extra parenthesis are the capturing group, so you can use $1 as the replacement.