How to do beautifully organized and commented regex?

Question

I am writing this regex to detect patterns like mypage?myvar1=myvalue2&myvar2&myvar3=myvalue3 : basically a simple file without extension + parameters regex.

So here is my code:

preg_match("#([a-zA-Z0-9]+)((\?)((([a-zA-Z0-9]+)((=)([a-zA-Z0-9]+))?)((&)([a-zA-Z0-9]+)((=)([a-zA-Z0-9]+))?)*))?#",$foo);

It's ugly and hard to understand right ?

So what I want to do is something like this :

    preg_match
    (
            "#
            ([a-zA-Z0-9]+)
            (
                (\?)
                (
                    (
                        ([a-zA-Z0-9]+)
                        (
                            (=)
                            ([a-zA-Z0-9]+)
                        )?
                    )
                    (
                        (&)
                        ([a-zA-Z0-9]+)
                        (
                            (=)
                            ([a-zA-Z0-9]+)
                        )?
                    )*
                )
            )?
            #"
            ,
            $foo
    );

and i also want to add comments at the end of each lines to further explain my code to future me when i review it again.

Of course if I do it like this I will have spaces and new lines that will mess my regex and it won't work.I also want to add comments at the end of some of the lines to further explain my code to future me when i review it again.

How do I do that ?

There's a comment/free-spacing/ignoreWhitespace/Verbose modifier: the x modifier. Put it after the end delimiter. As an aside, there are too much groups and capture groups in your pattern. — Casimir et Hippolyte, Jun 13 '16 at 15:41
@CasimiretHippolyte thanks I will change the delimiter to "/" to use #-induced comments with "x" pattern modifier. But why do you think there is too much capture groups in my pattern ? — shrimpdrake, Jun 13 '16 at 15:52
With PCRE (the regex engine used by PHP) x stands for "eXtended" — Casimir et Hippolyte, Jun 13 '16 at 15:56
@CasimiretHippolyte and about the number of capture groups in my pattern ? How would you do it ? — shrimpdrake, Jun 13 '16 at 15:58
@CasimiretHippolyte thanks for teh feedback but how are they useless ? how would you have done this code ? — shrimpdrake, Jun 13 '16 at 16:08
Sorry but I think that the best therapy is to make your own test with an online tester, to read about non-capturing groups, and to ask you the question: *Why grouping this token with this other token?* — Casimir et Hippolyte, Jun 13 '16 at 16:12

How to do beautifully organized and commented regex?

0 Answers0