Re^3: How to no goto or gosub

I find that unless() has a very small useful footprint. Sure, may be OK when there is a single condition:

unless ($things_went_wrong) { # do some stuff }
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But, when there are multiple conditions, it gets tougher to keep straight:

unless ($result < $HIGHEST_VALUE && ! $bad_results{$result}) { # stuff
+ }
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And then there is this legal, but almost much harder to follow, control structure:

unless ($result) {
    ## Do some stuff
}
elsif (!$result) {
    ## Do some other stuff
}
else {
    ## yet other stuff... 
}
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In the end, 'unless(') is just a way to type 'if (!)', but with more keystrokes and it has a better chance of making your brain hurt. And, you never have to worry about decoding double negatives, or re-writing them if your control statements need to grow down the line if you just use 'if (!)'.

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Re^4: How to no goto or gosub by johngg (Canon) on Jan 19, 2016 at 15:23 UTC
And then there is this legal, but almost much harder to follow, control structure: I've often wondered how many brains would explode if there was an `unless ( ... ) { ... } elsless ( ... ) { ... } else { ... }` construct in the language :-) Cheers, JohnGG	[reply] [d/l]
Re^4: How to no goto or gosub by SimonPratt (Friar) on Jan 19, 2016 at 15:38 UTC
Yeah, I tend to stay away from `elsif`. Of course there are exceptions (aren't there always?), but I find that creating a logic flow that depends on lots of `elsif` calls just encourages people to continue expanding the structure long beyond the point it should have been refactored (case in point - one of our monolithic scripts has something like 30 or 40 chained `elsif` statements) Yes, I agree that `unless` has a small useful footprint, but I also think that `if` and `elsif` (especially the latter) are very easy to abuse.	[reply] [d/l] [select]