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  • multiway conditionals

    From Rainer Weikusat@21:1/5 to All on Mon Jul 10 21:32:39 2023
    Perl 38 came with the announcement that the P5P have unfortunately not
    managed to get rid of the intellectual miscarriage named smartmatching
    and have therefore - at least that's how I understood the announcement - decided to throw the useful bit of that (the given/ when syntax) under a
    bus to avoid admitting that this DWNEWEHS-operator (Do What Nobody Else
    Would Ever Have Suspected) was a stupid idea.

    This reopens the question how to do multiway conditionals in perl. An
    IMHO sane way would be: Define two subroutines,

    sub matches
    {
    for my $x (@_) {
    return 1 if $_ == $x;
    }

    return;
    }

    sub str_matches
    {
    for my $x (@_) {
    return 1 if $_ eq $x;
    }

    return;
    }

    which can then be used as follows

    for ($! + 0) {
    matches(EINPROGRESS)
    and return NBFH_WANT_WRITE;

    matches(EACCES, EADDRNOTAVAIL, EAGAIN, ECONNREFUSED,
    ECONNRESET, ENETDOWN, ENETUNREACH, EPERM,
    ETIMEDOUT)
    and return NBFH_ERR;

    sys_die('connect');
    }

    [str_matches to be used for string matching]

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Popping Mad@21:1/5 to Rainer Weikusat on Wed Jul 12 23:05:18 2023
    On 7/10/23 16:32, Rainer Weikusat wrote:
    Perl 38 came with the announcement that the P5P have unfortunately not managed to get rid of the intellectual miscarriage named smartmatching
    and have therefore - at least that's how I understood the announcement - decided to throw the useful bit of that (the given/ when syntax) under a
    bus to avoid admitting that this DWNEWEHS-operator (Do What Nobody Else
    Would Ever Have Suspected) was a stupid idea.

    This reopens the question how to do multiway conditionals in perl. An
    IMHO sane way would be: Define two subroutines,

    sub matches
    {
    for my $x (@_) {
    return 1 if $_ == $x;
    }

    return;
    }

    sub str_matches
    {
    for my $x (@_) {
    return 1 if $_ eq $x;
    }

    return;
    }

    which can then be used as follows

    for ($! + 0) {
    matches(EINPROGRESS)
    and return NBFH_WANT_WRITE;

    matches(EACCES, EADDRNOTAVAIL, EAGAIN, ECONNREFUSED,
    ECONNRESET, ENETDOWN, ENETUNREACH, EPERM,
    ETIMEDOUT)
    and return NBFH_ERR;

    sys_die('connect');
    }

    [str_matches to be used for string matching]

    what is wrong with if?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Rainer Weikusat@21:1/5 to Popping Mad on Sun Jul 16 21:01:21 2023
    Popping Mad <[email protected]> writes:
    On 7/10/23 16:32, Rainer Weikusat wrote:
    Perl 38 came with the announcement that the P5P have unfortunately not
    managed to get rid of the intellectual miscarriage named smartmatching
    and have therefore - at least that's how I understood the announcement -
    decided to throw the useful bit of that (the given/ when syntax) under a
    bus to avoid admitting that this DWNEWEHS-operator (Do What Nobody Else
    Would Ever Have Suspected) was a stupid idea.

    This reopens the question how to do multiway conditionals in perl. An
    IMHO sane way would be: Define two subroutines,

    sub matches
    {
    for my $x (@_) {
    return 1 if $_ == $x;
    }

    return;
    }

    sub str_matches
    {
    for my $x (@_) {
    return 1 if $_ eq $x;
    }

    return;
    }

    which can then be used as follows

    for ($! + 0) {
    matches(EINPROGRESS)
    and return NBFH_WANT_WRITE;

    matches(EACCES, EADDRNOTAVAIL, EAGAIN, ECONNREFUSED,
    ECONNRESET, ENETDOWN, ENETUNREACH, EPERM,
    ETIMEDOUT)
    and return NBFH_ERR;

    sys_die('connect');
    }

    [str_matches to be used for string matching]

    what is wrong with if?

    It's not a multiway conditional, ie, one which evaluates an expression
    once and then provides a way to test the result for multiple values or
    sets of values.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)