Where is Fixnum#power! coming from?

ruby-talk
1

Hi all,

Ruby 1.8.4

I realize there's a Fixnum#power! method defined in rational.rb, but it appears that Fixnum has that method available to it whether or not I require rational.rb. I looked through the Ruby source and didn't see anything.

djberge@~-710>irb
irb(main):001:0> Fixnum.instance_methods(false).grep(/power/)
=> ["rpower", "power!"]

So, where the heck is it coming from?

Thanks,

Dan

2

I realize there's a Fixnum#power! method defined in rational.rb, but it appears that Fixnum has that method available to it whether or not I require rational.rb. I looked through the Ruby source and didn't see anything.

djberge@~-710>irb
irb(main):001:0> Fixnum.instance_methods(false).grep(/power/)
=> ["rpower", "power!"]

So, where the heck is it coming from?

$ irb -rubygems
> 2.power!(3)
=> 8
> exit
$ irb
> 2.power!(3)
NoMethodError: undefined method `power!' for 2:Fixnum
         from (irb):1

Are you requiring rubygems?

-- Daniel

···

On Mar 29, 2006, at 9:22 PM, Daniel Berger wrote:
         from :0

3

Daniel Berger wrote:

Hi all,

Ruby 1.8.4

I realize there's a Fixnum#power! method defined in rational.rb, but it appears that Fixnum has that method available to it whether or not I require rational.rb. I looked through the Ruby source and didn't see anything.

numeric.c:
flo_pow(x, y)...
fix_pow(x, y)...

and then:
rb_define_method(rb_cFixnum, "**", fix_pow, 1);
rb_define_method(rb_cFloat, "**", flo_pow, 1);

and then in rational.rb:

class Fixnum
    alias power! **
end

are You sure irb doesnt use rational.rb ?

lopex

4

Daniel Harple wrote:

···

On Mar 29, 2006, at 9:22 PM, Daniel Berger wrote:

I realize there's a Fixnum#power! method defined in rational.rb, but it appears that Fixnum has that method available to it whether or not I require rational.rb. I looked through the Ruby source and didn't see anything.

djberge@~-710>irb
irb(main):001:0> Fixnum.instance_methods(false).grep(/power/)
=> ["rpower", "power!"]

So, where the heck is it coming from?

$ irb -rubygems
> 2.power!(3)
=> 8
> exit
$ irb
> 2.power!(3)
NoMethodError: undefined method `power!' for 2:Fixnum
        from (irb):1
        from :0

Are you requiring rubygems?

-- Daniel

Aha! I'm not explicitly require'ing it, but my $RUBYOPT was set. Once I unset it, I got the expected error.

Thanks,

Dan

5

Daniel Berger wrote:

Daniel Harple wrote:

        from :0

Are you requiring rubygems?

-- Daniel

Aha! I'm not explicitly require'ing it, but my $RUBYOPT was set. Once
I unset
it, I got the expected error.

FYI:

RubyGems uses time.rb
time.rb uses parsedate.rb
parsedate.rb uses date/format.rb
date/format.rb uses rational.rb

···

--
-- Jim Weirich

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