Is there a way to have a character match a conjunction of character classes?-CodePudding

I'm trying to have a regex describe a single-quote-delimited string. Inside the string, I can have either any printable (or whitespace) character (which is NOT a single quote), OR a series of TWO single quotes, which would be an "escaped" single quote.

The [[:print:]] character class (also written as \p{XPosixPrint}) fits the bill for the characters I want to allow... except that it would ALSO allow a single "single quote" ('). Which I don't want to happen.

So, is there a simple way to do that, like, describing a character to match two expressions at the same time (like [[:print:]] and [^'] ), or do I have to create a custom character class enumerating everything I'm allowing (or forbidding) ?

CodePudding user response：

/(?!')\p{Print}/                     # Worst performance and kinda yuck?

/\p{Print}(?<!')/                    # Better performance but yuckier?

/[^\P{Print}']/                      # Best performance, but hard to parse.[1]

use experimental qw( regex_sets );   # No idea why still experimental.
/(?[ \p{Print} - ['] ])/             # Best performance and clearest.

/[^\p{Cn}\p{Co}\p{Cs}\p{Cc}']/       # Non-general solution.
                                     # Best performance but fragile.[2]

\p{Print} is an alias of \p{XPosixPrint}.

   char that is (printable and not('))
 = char that is (not(not(printable and not('))))
 = char that is (not(not(printable) or not(not('))))
 = char that is (not(not(printable) or '))
 = [^\P{Print}']

\p{Print} includes all the characters except unassigned, private use, surrogates and control characters.

/[^\p{Cn}\p{Co}\p{Cs}\p{Cc}']/

is short for

/[^\p{General_Category=Unassigned}\p{General_Category=Private_Use}\p{General_Category=Surrogates}\p{General_Category=Control}']/

use experimental qw( regex_sets );   # No idea why still experimental.
/(?[ !(
     \p{General_Category=Unassigned}
     \p{General_Category=Private_Use}
     \p{General_Category=Surrogates}
     \p{General_Category=Control}
     [']
) ])/