From: William James <w_a_x_man@...>
Date: 2005-08-13T05:36:11+09:00
Subject: Re: no clue

Joe Van Dyk wrote:
> On 8/12/05, William James <w_a_x_man@yahoo.com> wrote:
> > Joe Van Dyk wrote:
> > >I have a string like:
> > >
> > >"some_key: blah, some_other_key: more_blah,
> > > yet_other_key: yet_more_blah"
> > >
> > >I want to build up a hash like
> > >
> > >{ :some_key => "blah", :some_other_key => "more_blah",
> > > :yet_other_key => "yet_more_blah" }
> >
> > h={}
> > DATA.read.split(/\s*[:,\n]\s*/).inject(false){|a,b|
> >   if a then h[a.to_sym]=b; a=false else a=b end }
> >
> > p h
> > __END__
> > some_key: blah, some_other_key: more_blah, yet_other_key: yet_more_blah
> > key1:value1
> > key2:  value2
> > key3   : value 3  , key4 :value4 , key555555555:value55555
> >
> >
> > ----
> > Output:
> >
> > {:key3=>"value 3", :some_key=>"blah", :key4=>"value4",
> > :some_other_key=>"more_blah", :key555555555=>"value55555",
> > :yet_other_key=>"yet_more_blah", :key1=>"value1",
> > :key2=>"value2"}
>
> Why would this approach be faster?

data = []; DATA.each{|x| data << x.chomp}
iter = 100_000

h={}
start = Time.now

iter.times {
data.each{|line| line.split(/\s*[:,]\s*/).inject(false){|a,b|
  if a then h[a.to_sym]=b; a=false else a=b end }}
}
t1 = Time.now - start

result_hash = {}
start = Time.now

iter.times {
data.each{|line| line.scan(/(\w+)\s*:\s*([^, ]*)/) do |k, v|
  result_hash[k.to_sym] = v
end
} }
t2 = Time.now - start

p result_hash == h
p t1,t2

__END__
some_key: blah, some_other_key: more_blah, yet_other_key: yet_more_blah
key1:value1,key2: value2,key3 :value_3 ,
key4:value4,key555555555:value55555
x_position: 20, y_position: 40, z_position: 30,zz_position:85


Output:
true
22.859
28.094