Re: Critique yet another List-to-Range function

I like your code but would suggest that the output is perhaps incorrect. Surely the two ranges 0-2,2.5-4.5 are a single logical range 0-4.5??? The range concept becomes a bit iffy once you stop using integers. Any two numbers will constitute a range - it just depends on your step size. Using my definition that a range means that any two adjacent numbers within that range are no more than unity apart....the range should be 0-4.5 not the 0-2,2.5-4.5...

Anyway, did somebody say GOLF? A bloated 93 chars, surely well over par.

cheers

tachyon

@test =(1,2,2.5,3.5,4.5,7,6,-5,-6,-7,7,8,9,10,0,12,18);


sub range {
   @_=sort{$a<=>$b}@_;@r=($l)=$_[0];
   map{if(abs$l-$_>1){push@r,$r=$_;
   $r[-2].="~$l";}$l=$_;}@_;@r;
}

@result = range(@test);
print "$_\n" for @result;


Prints:
-7~-5
0~4.5
6~10
12~12
18
[download]

Comment on Re: Critique yet another List-to-Range function Download Code

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Re: Re: Critique yet another List-to-Range function by scott (Chaplain) on Jun 15, 2001 at 20:19 UTC
Surely the two ranges 0-2,2.5-4.5 are a single logical range 0-4.5??? The range concept becomes a bit iffy once you stop using integers. Any two numbers will constitute a range - it just depends on your step size. Heh, thanks. Too true. I therefore implement your definition via the replacement: `if ( $_ - $end_points[ 1 ] == 1 ) { $end_points[ 1 ]++; }` goes to `if ( $_ - $end_points[ 1 ] <= 1 ) { $end_points[ 1 ] = $_; }`	[reply] [d/l] [select]
Re: Re: Critique yet another List-to-Range function by shotgunefx (Parson) on Jun 19, 2002 at 02:11 UTC
For posterity sake, I thought I'd note that there is a problem with this. `#!/usr/bin/perl -w my @test = ((1..3), 5, (7..9), (11..12), (17..19)); sub range { @_=sort{$a<=>$b}@_;@r=($l)=$_[0]; map{if(abs$l-$_>1){push@r,$r=$_; $r[-2].="~$l";}$l=$_;}@_;@r; } my @ranged = range(@test); print "@test \n"; # prints 1 2 3 5 7 8 9 11 12 17 18 19 print "@ranged \n"; # prints 1~3 5~5 7~9 11~12 17` [download] -Lee "To be civilized is to deny one's nature."	[reply] [d/l]
Re: Re: Critique yet another List-to-Range function by larryk (Friar) on Jun 15, 2001 at 17:11 UTC
<golf> 3 trailing-semi-colons rear their ugly heads! (#90) `$r=` in the `push` ??? (#87) `abs` can go in favour of `if($_-$l>1)` (#84) </golf> but all this is in vain as the code is flawed -- in your example 12 has its own range (12~12) and it's the same for any single integer that doesn't fall in a range. "Argument is futile - you will be ignorralated!"	[reply] [d/l] [select]