From: Robert Klemme <bob.news@...>
Date: 2005-04-07T17:14:39+09:00
Subject: Re: new!


"Boris Glawe" <boris@boris-glawe.de> schrieb im Newsbeitrag
news:d31gaa$sio$1@newsreader3.netcologne.de...
> Robert wrote:
> > thanks a lot.
> > But what's the difference brtween C++ and Ruby?
> > I mean, why i should prefer ruby out of other programming languages?
> > Thank you again!
> >
>
> If you program ruby, you spend all your energy in solving your problem
and not
> in writing a very cryptic language. Ruby is a very clean and easy to
read
> object oriented language.
>
> The difference is speed!! I have an algoithm that runs 5 seconds with
c++ and 16
> minutes with ruby on my machine. The speed "problem" exists with all
skripting
> languages (perl,php, etc), it's not ruby's fault.

Your Derived#append is suboptimal because it creates new string instances
all the time.  Try

def append(t) @text << t; self end

And I'd rewrite Base#increase like this

def increase() @var += 1 end

It's shorter and it seems to be a tad faster:

>> Benchmark.bm(10) do |b|
>>   @var = 0
>>   b.report("+=") { 1000000.times { @var += 1 } }
>>   @var = 0
>>   b.report("= +") { 1000000.times { @var = @var + 1 } }
>> end
                user     system      total        real
+=          1.125000   0.000000   1.125000 (  1.132000)
= +         1.141000   0.000000   1.141000 (  1.146000)

Kind regards

    robert


> greets Boris
>
> ########### IN C++: ######################
>
> #include <iostream>
>
> using namespace std;
>
> class Base {
>
> public:
> Base(int x) : var(x)
> {}
>
> int getVar() const { return var; }
>
> void increase() { var++; }
> private:
> int var;
> };
>
>
>
> class Derived : public Base {
> public:
> Derived(int x, char* t) : Base(x), text(new string(t))
> {}
> ~Derived()
> {
> delete text;
> }
>
> string* getText() const { return text; }
> void append(string* t) {
> text->append(*t);
> }
>
> private:
> string* text;
> };
>
>
> int main (){
>
> Derived *d = new Derived(5, "hallo");
> cout << d->getVar() << endl;
>
> cout << *d->getText() << endl;
>
> string tmp = "bye";
> d->append(&tmp);
>
> cout << *d->getText() << endl;
> }
>
>
> ############ IN RUBY:########################
>
> #!/usr/bin/ruby
>
> class Base
> attr_reader :var
>
> def initialize(v)
> @var = v
> end
>
> def increase
> @var = @var + 1
> end
> end
>
>
>
> class Derived < Base
>
> attr_reader :text
>
> def initialize(x, t)
> super(x)
> @text = t
> end
>
> def append(t)
> @text = @text + t
> end
>
> end
>
>
> d = Derived.new(5, "hallo")
> d.increase
>
> print d.var.to_s +  "\n"
> print d.text + "\n"
>
> d.append("bye")
>
> print d.text + "\n"