[OT]: Re^9: What's the right way to write a method which returns one line at a time from a file?

Somewhat tangential, but a less messy, more readable and preferable (IMHO) version of this is:

return
    COND_A ? A  :
    COND_B ? B  :
    COND_C ? C  :
    COND_D ? () :  # returns undef or empty list per context
    die "unmatched case"
    ;
[download]

Give a man a fish: <%-{-{-{-<

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Re: [OT]: Re^9: What's the right way to write a method which returns one line at a time from a file? by eyepopslikeamosquito (Archbishop) on Nov 26, 2020 at 09:52 UTC
Yes, I agree. I especially like that there is only one `return` statement. In contrast, using multiple `return` statements violates the principle of DRY. Related items from Conway's Perl Best Practices, Chapter 6 (Control Structures): Avoid cascading an `if` Use table look-up in preference to cascaded equality tests When producing a value, use tabular ternaries Conway recommends formatting tabular ternaries with the colon at the front, for example: `# When their name is... Address them as... my $salute = $name eq $EMPTY_STR ? 'Customer' : $name =~ m/(.), \s+ Ph[.]?D \z /xms ? "Dr $1" : $name ;` [download] because, if you squint, it looks like a lookup table, thus converting the notoriously impenetrable ternary syntax into a familiar and easy to understand lookup table. Update:* Fixed typo in Conway's example `my $salute` statement above (removed extra `?`). Thanks AnomalousMonk.	[reply] [d/l] [select]
Re^2: [OT]: Re^9: What's the right way to write a method which returns one line at a time from a file? by AnomalousMonk (Archbishop) on Nov 26, 2020 at 10:07 UTC
`# When their name is... Address them as... my $salute = $name eq $EMPTY_STR ? 'Customer' : $name =~ m/(.*), \s+ Ph[.]?D \z /xms ? "Dr $1" : ? $name ;` [download] One ? too many: `Win8 Strawberry 5.8.9.5 (32) Thu 11/26/2020 5:03:36 C:\@Work\Perl\monks >perl -Mstrict -Mwarnings -l my $name = 'xyzzy'; my $salute = $name eq 'foo' ? 'Fooble' : $name eq 'bar' ? 'Barfly' : $name ; print $salute; ^Z xyzzy` [download] Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^3: [OT]: Re^9: What's the right way to write a method which returns one line at a time from a file? by eyepopslikeamosquito (Archbishop) on Nov 26, 2020 at 10:20 UTC
Yes, I've corrected the offending node. Thanks.	[reply]


There's more than one way to do things
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