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comp.lang.ruby

Convert numbers to "non-ascii" strings

David Miller

2/26/2008 3:46:00 PM

Hello all

I would like to convert integers to strings in a way that I haven't come
across in the Ruby functions I have looked at. I would like the string
to be exactly what the integer would be if I read it in from a binary file.

In other words, the integer 0x61626364 would be the string "abcd" after
the conversion. I can write code to do it, but I think there is
probably a better way than the approach I have come up with.

This works but seems very brute force to me:

# assumes 32 bit numbers.
class Bignum
def to_ls
i = self
s = ""
4.times { s.concat(i & 0xff); i >>= 8}
return s.reverse
end
end


puts 0x61626364.to_ls
abcd



Also, it seems that I need this for both Bignum and Fixnum to cover the
entire 32 bit number range.



Thanks

Dave M
4 Answers

Consultant1guru

2/27/2008 6:18:00 AM

0

On Feb 26, 8:46 am, Dave M <dmil...@tecolote.net> wrote:
> Hello all
>
> I would like to convert integers to strings in a way that I haven't come
> across in the Ruby functions I have looked at. I would like the string
> to be exactly what the integer would be if I read it in from a binary file.
>
> In other words, the integer 0x61626364 would be the string "abcd" after
> the conversion. I can write code to do it, but I think there is
> probably a better way than the approach I have come up with.
>
> This works but seems very brute force to me:
>
> # assumes 32 bit numbers.
> class Bignum
> def to_ls
> i = self
> s = ""
> 4.times { s.concat(i & 0xff); i >>= 8}
> return s.reverse
> end
> end
>
> puts 0x61626364.to_ls
> abcd
>
> Also, it seems that I need this for both Bignum and Fixnum to cover the
> entire 32 bit number range.
>
> Thanks
>
> Dave M

Dave --

I'm afraid that you may have selected the incorrect language for the
task at hand. Your question implies that you are doing some complex
parsing or homogenization, and Ruby, while a nice scripting language
for small tasks, is simply not a good choice for that application. If
you want to do simple web development or a little scraping, Ruby is
good for that, but that's about the extent of what it can really
handle well.

I suggest you look at Perl or TCL for a serious scripting language,
Java for a robust programming language, and Visual Basic if you want
an ultra-fast development environment. These are tools that can
handle the task you describe in a sensible way.

I am not saying that you should give up Ruby. Ruby is great for
learning some of the object-oriented concepts that while interesting,
may not be practical for some tasks in the real world.

Hope that helps

Cheers

G

Clifford Heath

2/27/2008 6:30:00 AM

0

Consultant1guru@hotmail.com wrote:
> I'm afraid that you may have selected the incorrect language for the
> task at hand. Your question implies that you are doing some complex
> parsing or ...

Nothing whatever complex about it, quite simple in Ruby:

class Numeric
def to_ls
[self].pack("N")
end
end

Works for BigNum and FixNum, no need to modify those classes.

Clifford Heath.

Joel VanderWerf

2/27/2008 6:40:00 AM

0

Consultant1guru@hotmail.com wrote:
> On Feb 26, 8:46 am, Dave M <dmil...@tecolote.net> wrote:
>> Hello all
>>
>> I would like to convert integers to strings in a way that I haven't come
>> across in the Ruby functions I have looked at. I would like the string
>> to be exactly what the integer would be if I read it in from a binary file.
>>
>> In other words, the integer 0x61626364 would be the string "abcd" after
>> the conversion. I can write code to do it, but I think there is
>> probably a better way than the approach I have come up with.
>>
>> This works but seems very brute force to me:
>>
>> # assumes 32 bit numbers.
>> class Bignum
>> def to_ls
>> i = self
>> s = ""
>> 4.times { s.concat(i & 0xff); i >>= 8}
>> return s.reverse
>> end
>> end
>>
>> puts 0x61626364.to_ls
>> abcd
>>
>> Also, it seems that I need this for both Bignum and Fixnum to cover the
>> entire 32 bit number range.
>>
>> Thanks
>>
>> Dave M
>
> Dave --
>
> I'm afraid that you may have selected the incorrect language for the
> task at hand. Your question implies that you are doing some complex
> parsing or homogenization, and Ruby, while a nice scripting language
> for small tasks, is simply not a good choice for that application. If
> you want to do simple web development or a little scraping, Ruby is
> good for that, but that's about the extent of what it can really
> handle well.
>
> I suggest you look at Perl or TCL for a serious scripting language,
> Java for a robust programming language, and Visual Basic if you want
> an ultra-fast development environment. These are tools that can
> handle the task you describe in a sensible way.
>
> I am not saying that you should give up Ruby. Ruby is great for
> learning some of the object-oriented concepts that while interesting,
> may not be practical for some tasks in the real world.
>
> Hope that helps
>
> Cheers
>
> G

Please reconsider your assessment of ruby, G.

[0x61626364].pack("N")

This returns the string "abcd" and does so elegantly and efficiently.

In my experience and that of many others on this mailing list, ruby can
be used for a variety of complex tasks, and not just web apps. Also,
like perl, it makes simple tasks simple.

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

David Miller

2/28/2008 4:52:00 AM

0

Joel VanderWerf wrote:
> Consultant1guru@hotmail.com wrote:
>> On Feb 26, 8:46 am, Dave M <dmil...@tecolote.net> wrote:
>>> Hello all
>>>
>>> I would like to convert integers to strings in a way that I haven't come
>>> across in the Ruby functions I have looked at. I would like the string
>>> to be exactly what the integer would be if I read it in from a binary file.
>>>
>>> In other words, the integer 0x61626364 would be the string "abcd" after
>>> the conversion. I can write code to do it, but I think there is
>>> probably a better way than the approach I have come up with.
>>>
>>> This works but seems very brute force to me:
>>>
>>> # assumes 32 bit numbers.
>>> class Bignum
>>> def to_ls
>>> i = self
>>> s = ""
>>> 4.times { s.concat(i & 0xff); i >>= 8}
>>> return s.reverse
>>> end
>>> end
>>>
>>> puts 0x61626364.to_ls
>>> abcd
>>>
>>> Also, it seems that I need this for both Bignum and Fixnum to cover the
>>> entire 32 bit number range.
>>>
>>> Thanks
>>>
>>> Dave M
>> Dave --
>>
>> I'm afraid that you may have selected the incorrect language for the
>> task at hand. Your question implies that you are doing some complex
>> parsing or homogenization, and Ruby, while a nice scripting language
>> for small tasks, is simply not a good choice for that application. If
>> you want to do simple web development or a little scraping, Ruby is
>> good for that, but that's about the extent of what it can really
>> handle well.
>>
>> I suggest you look at Perl or TCL for a serious scripting language,
>> Java for a robust programming language, and Visual Basic if you want
>> an ultra-fast development environment. These are tools that can
>> handle the task you describe in a sensible way.
>>
>> I am not saying that you should give up Ruby. Ruby is great for
>> learning some of the object-oriented concepts that while interesting,
>> may not be practical for some tasks in the real world.
>>
>> Hope that helps
>>
>> Cheers
>>
>> G
>
> Please reconsider your assessment of ruby, G.
>
> [0x61626364].pack("N")
>
> This returns the string "abcd" and does so elegantly and efficiently.
>
> In my experience and that of many others on this mailing list, ruby can
> be used for a variety of complex tasks, and not just web apps. Also,
> like perl, it makes simple tasks simple.
>

Thanks for the response to both Cliff and Joel. As I suspected, there
was a simple answer right in front of my nose -- I just didn't see it.
Your help is much appreciated.

As to "G", all I have to say is umm ... Thanks for nothing.

Dave M