[Python-Dev] Re: Pattern matching reborn: PEP 622 is dead, long live PEP 634, 635, 636

31 Oct 2020

      On Sat, 31 Oct 2020 at 17:49, Paul Sokolovsky  wrote:
...
Alternatively, can add "inline guard sigils" for the most common guard
conditions, which would be equality, period:
match r:
    case (src, None):
    case (==c, msg):
    case (==s, msg):
`==` interacts poorly with other aspects of the pattern syntax (most
notably keywords in class patterns), but PEP 642's identity constraint
expressions would allow:

     match r:
        case (src, ?is None):
            ... # Any src, msg is None
        case (?is c, msg):
            ... # Any msg, src is c
        case (?is s, msg):
            ... # Any msg, src is s

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan@gmail.com   |   Brisbane, Australia