From: William James <w_a_x_man@...>
Date: 2006-12-26T05:25:05+09:00
Subject: Re: Regexp Question: Checking for pairs

Andrew Johnson wrote:
> William James wrote:
> [snip]
> >
> > Rehearsal ------------------------------------------
> > regexp   6.870000   0.000000   6.870000 (  7.391000)
> > array    2.653000   0.000000   2.653000 (  2.874000)
> > --------------------------------- total: 9.523000sec
> >
> >              user     system      total        real
> > regexp   6.940000   0.000000   6.940000 (  7.441000)
> > array    2.634000   0.000000   2.634000 (  2.854000)
> >
> > 10000
> > 10000
>
>
> The regex engine makes a difference in this case -- ruby1.8.5 + the
> oniguruma engine gives:
>
>
>   Rehearsal ------------------------------------------
>   regexp   2.740000   0.010000   2.750000 (  2.960385)
>   array    3.120000   0.000000   3.120000 (  3.120808)
>   --------------------------------- total: 5.870000sec
>
>                user     system      total        real
>   regexp   2.750000   0.000000   2.750000 (  2.743031)
>   array    3.140000   0.000000   3.140000 (  3.137098)
>
>   10000
>   10000
>
>
> cheers,
> andrew

Oh, yeah?  Try this on for size, Oni!

require 'benchmark'

$n = 10_000
$strings = [
  %Q{
  good [joe] Wasn't that what [i]he[/i] was seeking? [/joe]
     [joe] Can't you [b]see[/b] that? [/joe]
  Early one June morning in 1872 I murdered my father---an act
  which made a deep impression on me at the time.

  We know better the needs of ourselves than of others. To
  serve oneself is economy of administration.

  self-evident, adj.  Evident to one's self and to nobody else.

  senate, n.  A body of elderly gentlemen charged with high
  duties and misdemeanors.
  [joe]
  "Thou wretch! -- thou vixen! -- thou shrew!" said I to my
  wife on the morning after our wedding; "thou witch! -- thou
  hag! -- thou whippersnapper -- thou sink of iniquity! --
  thou fiery-faced quintessence of all that is abominable! --
  thou -- thou--" here standing upon tiptoe, seizing her by the
  throat, and placing my mouth close to her ear, I was   [/joe]
  preparing to launch forth a new and more decided epithet of
  opprobrium, which should not fail, if ejaculated, to
  convince her of her insignificance, when to my extreme
  horror and astonishment I discovered that I had [i]lost my
  breath[/i].
  },
  "bad was Peck's boy [/joe] [joe] But he'll never know. [/joe]",
  "bad to the bone [joe] Or will he?! [/joe] mish mash mush
   Marching on Tom Tidler's ground fatigues me.  [/joe]",
  "bad: too many [joe] [/joe] [joe] [/joe] [joe] [/joe] [joe] [/joe]",
  "bad: too few"
]

def regexp
  $regexp_good = 0
  $n.times{ $strings.each { |s|
    $regexp_good += 1   if s =~
/\A(((?!\[\/?joe\]).)*(\[joe\]((?!\[\/?joe\]).)+\[\/joe\])){1,3}((?!\[\/?joe\]).)*\Z/m
  } }
end
def array
  $array_good = 0
  $n.times{ $strings.each { |s|
    ary = s.scan( %r{\[/?joe\]} )
    if [2,4,6].include?(ary.size)  and
      ary == ary.partition{|t| "[joe]"==t}.inject{|a,b| a.zip(b)}.
        flatten
      $array_good += 1
    end
  } }
end

Benchmark.bmbm do |x|
  x.report("regexp") { regexp }
  x.report("array")  { array  }
end

puts  ;  p $regexp_good, $array_good

Rehearsal ------------------------------------------
regexp  29.432000   3.354000  32.786000 ( 36.513000)
array    3.225000   0.000000   3.225000 (  3.485000)
-------------------------------- total: 36.011000sec

             user     system      total        real
regexp  29.382000   3.656000  33.038000 ( 36.793000)
array    3.195000   0.000000   3.195000 (  3.525000)

10000
10000