Re: Super regexp to format numbers

29.08.06, 03:18, A. Pagaltzis <[email protected]>:



> * Alexandre Jousset <[email protected]> [2006-08-28 22:55]:

> > 	It works only for integers...

> This list is “fun with Perl.” Splitting a string at the dot char

> is not very fun, no? I considered that part to be obvious.



  and now, benchmarking:



  # perl -MBenchmark=timethese -de0

    DB<1> $a = "21285063.14"



    DB<2> sub A () { local $_ = $a; 1 while s/^([-+]?\d+)(\d{3})/$1,$2/; return $_; }



    DB<3> sub B () { local $_ = $a; s/(^[-+]?\d+?(?=(?>(?:\d{3})+)(?!\d))|\G\d{3}(?=\d))/$1,/g; return $_; }



    DB<4> sub C () { my ($aa,$bb) = split "\\.",$a; return scalar (reverse join ' ', unpack '(A3)*', reverse $aa) . ".$bb"; }



    DB<5> timethese (1_000_000,{'A' => \&A,'B' => \&B,'C' => \&C})

  Benchmark: timing 1000000 iterations of A, B, C...

         A: 27 wallclock secs (17.16 usr +  0.02 sys = 17.18 CPU) @ 58207.22/s (n=1000000)

         B: 21 wallclock secs (14.59 usr +  0.01 sys = 14.60 CPU) @ 68493.15/s (n=1000000)

         C:  6 wallclock secs ( 6.12 usr + -0.02 sys =  6.10 CPU) @ 163934.43/s (n=1000000)







-- 

wbw, artur