Forum: Ruby Euro currency symbol

Hmm, I seem to be having a bit of a time representing  the Euro sign in
Ruby.

ruby -v
ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]
(same results on a linux box, 1.8.5 with Ruby)

symbol: €
Decimal: 8364
hex: 20Ac
html number: €
html name: €
description: euro sign


dwright@[1061]:dwright% perl -C2 -le 'print chr(oct("20254"))'
€

dwright@[1062]:dwright%ruby -le 'puts "20254".oct.chr'
-e:1:in `chr': 8364 out of char range (RangeError)
  from -e:1

dwright@[1063]:dwright%irb
>> puts "20254".oct
8364


>> puts "20254".oct.chr
RangeError: 8364 out of char range
  from (irb):5:in `chr'
  from (irb):5

ruby -e 'puts "20Ac".hex.chr'
-e:1:in `chr': 8364 out of char range (RangeError)
  from -e:1


ruby -KU -e 'puts "20Ac".hex.chr'
-e:1:in `chr': 8364 out of char range (RangeError)
  from -e:1

ruby -KU -e '$KCODE="u";puts "20Ac".hex.chr'
-e:1:in `chr': 8364 out of char range (RangeError)
  from -e:1

 ruby -e "puts '20Ac'.hex.chr"
-e:1:in `chr': 8364 out of char range (RangeError)
  from -e:1

Here's the pound:

ruby -e 'puts "The pound:\243"'
The pound:£

ruby -e 'puts "243".oct.chr'
£

David Wright wrote:
> Hmm, I seem to be having a bit of a time representing  the Euro sign in
> Ruby.
> 
> ruby -v
> ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]
> (same results on a linux box, 1.8.5 with Ruby)
> 
> symbol: €
> Decimal: 8364
> hex: 20Ac
> html number: €
> html name: €
> description: euro sign
> 
> 
> dwright@[1061]:dwright% perl -C2 -le 'print chr(oct("20254"))'
> €
> 
> dwright@[1062]:dwright%ruby -le 'puts "20254".oct.chr'
> -e:1:in `chr': 8364 out of char range (RangeError)
>   from -e:1
> 
> dwright@[1063]:dwright%irb
>>> puts "20254".oct
> 8364
> 
> 
>>> puts "20254".oct.chr
> RangeError: 8364 out of char range
>   from (irb):5:in `chr'
>   from (irb):5
> 
> ruby -e 'puts "20Ac".hex.chr'
> -e:1:in `chr': 8364 out of char range (RangeError)
>   from -e:1
> 
> 
> ruby -KU -e 'puts "20Ac".hex.chr'
> -e:1:in `chr': 8364 out of char range (RangeError)
>   from -e:1
> 
> ruby -KU -e '$KCODE="u";puts "20Ac".hex.chr'
> -e:1:in `chr': 8364 out of char range (RangeError)
>   from -e:1
> 
>  ruby -e "puts '20Ac'.hex.chr"
> -e:1:in `chr': 8364 out of char range (RangeError)
>   from -e:1
> 
> Here's the pound:
> 
> ruby -e 'puts "The pound:\243"'
> The pound:£
> 
> ruby -e 'puts "243".oct.chr'
> £


dec_num = "20254".oct
puts dec_num

--output:--
8364


$ri chr
------------------------------------------------------------ Integer#chr
     int.chr    => string
------------------------------------------------------------------------
     Returns a string containing the ASCII character represented by the
     receiver's value.

        65.chr    #=> "A"
        ?a.chr    #=> "a"
        230.chr   #=> "\346"


There is no ascii character with an ascii code equal to 8364.  The pound 
has been around a long time, and it made it into extended ascii (or 
latin-1, which uses 8 bits).  The euro is a recent invention, and it's 
numerical code is way out in unicode land.

arr = []
arr << dec_num
str = arr.pack("U")  #U=UTF-8 => encode unicode 8364 into a UTF-8 
character.
puts str

--output:--
€

7stud -- wrote:
> 
> $ri chr
> ------------------------------------------------------------ Integer#chr
>      int.chr    => string
> ------------------------------------------------------------------------
>      Returns a string containing the ASCII character represented by the
>      receiver's value.
> 
>         65.chr    #=> "A"
>         ?a.chr    #=> "a"
>         230.chr   #=> "\346"
> 
> 
> There is no ascii character with an ascii code equal to 8364.  The pound 
> has been around a long time, and it made it into extended ascii (or 
> latin-1, which uses 8 bits).  

8 bits can be used to store codes between 0-255.

ascii characters are represented by numerical codes between 0-127, so 
the text describing the operation of chr in the docs is wrong. 
According to the description, you would expect codes above 127 to 
produce errors.  But codes between 127-255 do not produce errors.  The 
last example demonstrates that.  The docs should read something like:

Returns a string containing the latin-1 (or ISO-8859-1) character 
represented by the receiver's value.  Valid character codes are 0-255.

7stud -- wrote:
> 7stud -- wrote:
>> 
>> $ri chr
>> ------------------------------------------------------------ Integer#chr
>>      int.chr    => string
>> ------------------------------------------------------------------------
>>      Returns a string containing the ASCII character represented by the
>>      receiver's value.
>> 
>>         65.chr    #=> "A"
>>         ?a.chr    #=> "a"
>>         230.chr   #=> "\346"
>> 
>> 
>> There is no ascii character with an ascii code equal to 8364.  The pound 
>> has been around a long time, and it made it into extended ascii (or 
>> latin-1, which uses 8 bits).  
> 
> 8 bits can be used to store codes between 0-255.
> 
> ascii characters are represented by numerical codes between 0-127, so 
> the text describing the operation of chr in the docs is wrong. 
> According to the description, you would expect codes above 127 to 
> produce errors.  But codes between 127-255 do not produce errors.  The 
> last example demonstrates that.  The docs should read something like:
> 
> Returns a string containing the latin-1 (or ISO-8859-1) character 
> represented by the receiver's value.  Valid character codes are 0-255.


Thanks, good stuff.  I didn't know about Array#pack

Sure, I'm familiar with character sets, I was assuming the 'same as 
Perl' chr functionality, I should have checked the rdoc for chr,...

Perl:
 chr     Returns the character represented by that NUMBER in the
               character set.  For example, "chr(65)" is "A" in either 
ASCII
               or Unicode, and chr(0x263a) is a Unicode smiley face.


Ruby:
     int.chr    => string
------------------------------------------------------------------------
     Returns a string containing the ASCII character represented by the
     receiver's value.

ruby -e 'puts "\244"'


David Wright a écrit :
>>>         ?a.chr    #=> "a"
>> According to the description, you would expect codes above 127 to 
> Perl' chr functionality, I should have checked the rdoc for chr,...
> ------------------------------------------------------------------------
>      Returns a string containing the ASCII character represented by the
>      receiver's value.
> 
irb(main):019:0> str = "\244"
=> "\244"
irb(main):020:0> puts str
€
=> nil