Look and think good things about D

[bearophile]

Ary Borenszweig:

> Here's what I was able to do in some minutes:
>
> ---
> if ARGV.length != 1
>   puts "missing argument: n"
>   exit 1
> end
>
> n = ARGV[0].to_i
> str = "1"
> buffer = String::Buffer.new(20)
> n.times do
>   puts str.length
>   str.each_chunk do |digit, count|
>     buffer << '0' + count
>     buffer << digit
>   end
>   str = buffer.to_s
>   buffer.clear
> end
>
> With n=70 it takes about 4.89s. With n=45 it takes about 0.012s.

This program is much longer in number of tokens to the first D 
program. You can write a D program about as fast as this in about 
the same number of tokens.

Perhaps I should add an intermediate third version that shows 
code that's not as extreme as the two versions there. Thank you 
for the implicit suggestion.


> And with Crystal you could do the second version as well, 
> because you have access to low level stuff like pointers.

In Crystal do you have final switches, gotos, etc too?


> And also, the language is pretty new so there's still
> a lot of optimizations to be done.

And LDC2 will improve in the meantime.


> I also thought ranges were pretty fast because of their nature.

It also matters a lot how you use them, this is normal in 
computer programming.


> Why are they slow in this example?

Just because the first example is not written for speed, I didn't 
even add run-time timings for it at first. And it's not that slow.

Bye,
bearophile