Anyone know why the first three of these calculations works on my irb (on intel OS X 10.4.8), but the last one silently hangs?
>> (DateTime.now - Date.new(2006,9,15)).to_f / 30
=> 3.18572031018981
>> (DateTime.now - Date.new(2006,9,15)).to_f/ 30
=> 3.18572102628549
>> (DateTime.now - Date.new(2006,9,15)).to_f/30
=> 3.18572174544174
>> (DateTime.now - Date.new(2006,9,15)).to_f /30
<not a lot happening>
^C
Ashley
Ashley Moran wrote:
Anyone know why the first three of these calculations works on my irb
(on intel OS X 10.4.8), but the last one silently hangs?(DateTime.now - Date.new(2006,9,15)).to_f / 30
=> 3.18572031018981
(DateTime.now - Date.new(2006,9,15)).to_f/ 30
=> 3.18572102628549
(DateTime.now - Date.new(2006,9,15)).to_f/30
=> 3.18572174544174
(DateTime.now - Date.new(2006,9,15)).to_f /30
Irb takes the latter as the beginning of a regular expression for the
first argument of to_f:
(DateTime.now - Date.new(2006,9,15)).to_f /30
/
ArgumentError: wrong number of arguments (1 for 0)
from (irb):10:in `to_f'
from (irb):10
from /usr/lib/ruby/1.8/rational.rb:520
Cheers,
Vince
--
Vincent Fourmond, PhD student
http://vincent.fourmond.neuf.fr/
Thanks Vince, cleared that up
I wondered why that didn't work but "10 /5" did
Ashley
On 19 Dec 2006, at 14:06, Vincent Fourmond wrote:
Irb takes the latter as the beginning of a regular expression for the
first argument of to_f:(DateTime.now - Date.new(2006,9,15)).to_f /30
/
ArgumentError: wrong number of arguments (1 for 0)
from (irb):10:in `to_f'
from (irb):10
from /usr/lib/ruby/1.8/rational.rb:520Cheers,
Vince
Ashley Moran wrote:
Anyone know why the first three of these calculations works on my irb
(on intel OS X 10.4.8), but the last one silently hangs?(DateTime.now - Date.new(2006,9,15)).to_f / 30
=> 3.18572031018981
(DateTime.now - Date.new(2006,9,15)).to_f/ 30
=> 3.18572102628549
(DateTime.now - Date.new(2006,9,15)).to_f/30
=> 3.18572174544174
(DateTime.now - Date.new(2006,9,15)).to_f /30
Irb takes the latter as the beginning of a regular expression for the
first argument of to_f:
...therefore IRB is still waiting for input. But you should see the a
prompt when you hit enter, with a different ending character (/ instead of
On Tue, 19 Dec 2006 23:06:05 +0900, Vincent Fourmond wrote:
) to indicate that IRB is still waiting for input.
(DateTime.now - Date.new(2006,9,15)).to_f /30
/
ArgumentError: wrong number of arguments (1 for 0)
from (irb):10:in `to_f'
from (irb):10
from /usr/lib/ruby/1.8/rational.rb:520Cheers,
Vince
--
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/
to_f vs /
I'll add the appriopriate params to show you what the parser sees:
(DateTime.now - Date.new(2006,9,15)).to_f ( /30 ) # /30 is taken in as a
single param because of lack of space and because you're calling to_f
10 /5 => 10./(5) # In this case, / IS the method call, as 10 is not a
method, so the parser figures this out correctly.
Either way, just put spaces there. It looks better and is easier to read.
Jason
On 12/19/06, Ashley Moran <work@ashleymoran.me.uk> wrote:
On 19 Dec 2006, at 14:06, Vincent Fourmond wrote:
> Irb takes the latter as the beginning of a regular expression for
> the
> first argument of to_f:
>
>>> (DateTime.now - Date.new(2006,9,15)).to_f /30
> /
> ArgumentError: wrong number of arguments (1 for 0)
> from (irb):10:in `to_f'
> from (irb):10
> from /usr/lib/ruby/1.8/rational.rb:520
>
> Cheers,
>
> VinceThanks Vince, cleared that up
I wondered why that didn't work but "10 /5" did
Ashley
Ken Bloom wrote:
Ashley Moran wrote:
Anyone know why the first three of these calculations works on my irb
(on intel OS X 10.4.8), but the last one silently hangs?(DateTime.now - Date.new(2006,9,15)).to_f / 30
=> 3.18572031018981
(DateTime.now - Date.new(2006,9,15)).to_f/ 30
=> 3.18572102628549
(DateTime.now - Date.new(2006,9,15)).to_f/30
=> 3.18572174544174
(DateTime.now - Date.new(2006,9,15)).to_f /30
Irb takes the latter as the beginning of a regular expression for the
first argument of to_f:...therefore IRB is still waiting for input.
But you should see the a
prompt when you hit enter, with a different ending character (/ instead of
) to indicate that IRB is still waiting for input.
Actually, no: I did type the /. This way, I finish the regexp started
on the previous line, and the expression is parsed and causes an error.
By the way, is there a way to define a secondary prompt in IRB ?
Vince
On Tue, 19 Dec 2006 23:06:05 +0900, Vincent Fourmond wrote:
--
Vincent Fourmond, PhD student
http://vincent.fourmond.neuf.fr/
One more thing to help you understand:
(DateTime.now - Date.new(2006,9,15)).to_f() /30 # this will work
On 12/19/06, Jason Roelofs <jameskilton@gmail.com> wrote:
On 12/19/06, Ashley Moran <work@ashleymoran.me.uk> wrote:
>
> On 19 Dec 2006, at 14:06, Vincent Fourmond wrote:
>
> > Irb takes the latter as the beginning of a regular expression for
> > the
> > first argument of to_f:
> >
> >>> (DateTime.now - Date.new (2006,9,15)).to_f /30
> > /
> > ArgumentError: wrong number of arguments (1 for 0)
> > from (irb):10:in `to_f'
> > from (irb):10
> > from /usr/lib/ruby/1.8/rational.rb:520
> >
> > Cheers,
> >
> > Vince
>
> Thanks Vince, cleared that up
>
> I wondered why that didn't work but "10 /5" did
>
> Ashleyto_f vs /
I'll add the appriopriate params to show you what the parser sees:
(DateTime.now - Date.new(2006,9,15)).to_f ( /30 ) # /30 is taken in as a
single param because of lack of space and because you're calling to_f10 /5 => 10./(5) # In this case, / IS the method call, as 10 is not a
method, so the parser figures this out correctly.Either way, just put spaces there. It looks better and is easier to read.
Jason
Vincent Fourmond:
By the way, is there a way to define a secondary prompt in IRB ?
Maybe that is :PROMPT_S.
IRB.conf[:PROMPT][:CUSTOM] = {
:PROMPT_I => # Insert
:PROMPT_C => # your
:PROMPT_N => # favorite
:PROMPT_S => # strings
:RETURN => # here
}
IRB.conf[:PROMPT_MODE] = :CUSTOM
Kalman