Re: A more concise way to map the contents of an array.

in reply to A more concise way to map the contents of an array.

you could use the conditional operator aka "ternary operator" :

my @cell_contents = map { $_ ? 1 : 0 } @$array_ref[3..10];

another idea is to use doubled negation "!!" and to map the empty string (false) to 0.

my @cell_contents = map { 0 + !!$_ } @$array_ref[3..10];

but I don't think this conciseness justifies the loss of readability.š

Cheers Rolf

š) well if you really need 0 for false.

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Re^2: A more concise way to map the contents of an array. by muba (Priest) on Dec 30, 2012 at 13:23 UTC
I don't think it gets much more concise than that. However, yet another way to achieve the same would be `@cell_contents = map { $_ and 1 or 0 } @$array_ref[3..10]` [download]	[reply] [d/l]
Re^2: A more concise way to map the contents of an array. by Amblikai (Scribe) on Dec 30, 2012 at 13:43 UTC
I like the first one you wrote, i hadn't come across that operator. Seems exactly the same as a conditional statement in Verilog. So it's still pretty readable to me! Regarding your footnote, supposing i didn't need 0 for false, how would i do it? And how else can you represent false? Thanks very much for your very helpful reply.	[reply]
Re^3: A more concise way to map the contents of an array. by LanX (Saint) on Dec 30, 2012 at 13:55 UTC
> Regarding your footnote, supposing i didn't need 0 for false, how would i do it? And how else can you represent false? Just use the product of a doubled negation to get clear booleans!š Perl's definition of false covers different data types and context cases. from perldata `A scalar value is interpreted as TRUE in the Boolean sense if i +t is not the null string or the number 0 (or its string equivalent, "0") +. The Boolean context is just a special kind of scalar context where +no conversion to a string or a number is ever performed.` [download] (Null string here means either empty string `""` or `undef`) from perlsyn `Truth and Falsehood The number 0, the strings '0' and '', the empty list "()", and +"undef" are all false in a boolean context. All other values are true. Negation of a true value by "!" or "not" returns a special fals +e value. When evaluated as a string it is treated as '', but as a number +, it is treated as 0.` [download] Cheers Rolf š) in this case `my @cell_contents = map { !!$_ } @$array_ref[3..10];` for me the most readable alternative!	[reply] [d/l] [select]
Re^4: A more concise way to map the contents of an array. by Amblikai (Scribe) on Dec 30, 2012 at 13:59 UTC
So just to be clear, if i double negate something, i'll lose the original "value" and be left with the pure boolean representation of the data? That could prove useful! Thanks again for your reply!	[reply]
Re^5: A more concise way to map the contents of an array. by Athanasius (Archbishop) on Dec 30, 2012 at 14:42 UTC
Re^6: A more concise way to map the contents of an array. by Amblikai (Scribe) on Dec 30, 2012 at 16:11 UTC
Re^5: A more concise way to map the contents of an array. by LanX (Saint) on Dec 30, 2012 at 14:03 UTC
Re^6: A more concise way to map the contents of an array. by Amblikai (Scribe) on Dec 30, 2012 at 14:31 UTC

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