# Ripper and Ruby 1.8

**URL:** <https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672>\
**Category:** Ruby\
**Created:** [August 20, 2006, 1:08pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672 "2006-08-20T13:08:37Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 1:08pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/1 "2006-08-20T13:08:37Z")

</div>

Hi all,

For the past two days I’ve been trying to get Ripper to compile with  
Ruby 1.8  
After searching and semi-translating some Japanese messages [1] with  
Babelfish I managed to compile Ripper for 1.8 but when using it I get an  
error-message: [Ripper - FATAL] : Unknown token 357 (or something like  
that)

Does anyone here have experience with getting Ripper working under 1.8?  
Does anyone know the specifics as to why Ripper states it needs 1.9?  
Does it have to do with parse.y?

Any information on the subject is really really appreciated.

With kind regards,  
Jonathan

[1] : [http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-dev/26851](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-dev/26851)

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<div class="post-metadata">

**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 2:22pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/2 "2006-08-20T14:22:39Z")

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Hi,

At Sun, 20 Aug 2006 20:07:16 +0900,  
Jonathan M. wrote in [ruby-talk:209477]:

> Does anyone know the specifics as to why Ripper states it needs 1.9?  
> Does it have to do with parse.y?

Ripper needs bison, but 1.8 can be compiled with other yaccs.

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<div class="post-metadata">

**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 5:40pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/3 "2006-08-20T17:40:57Z")

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removed\_email\_address@domain.invalid wrote:

> Hi,
> 
> Ripper needs bison, but 1.8 can be compiled with other yaccs.

Thanks for the reply but I’m a bit at a loss here. I’m a total noob  
regarding Ruby’s compilation process so I’m sorry if this is a stupid  
question but if I have bison available why should I not be able to  
compile Ripper against 1.8?

Thanks,  
Jonathan

---

<div class="post-metadata">

**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 7:53pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/4 "2006-08-20T19:53:11Z")

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Hi,

On Sun, 20 Aug 2006 17:39:40 +0200, Jonathan M.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Thanks for the reply but I’m a bit at a loss here. I’m a total noob  
> regarding Ruby’s compilation process so I’m sorry if this is a stupid  
> question but if I have bison available why should I not be able to  
> compile Ripper against 1.8?

I don’t know how to get Ripper working, but depending on what you want  
to  
do, there might be better solutions like RubyNode or ParseTree.

For example with RubyNode ([http://rubynode.rubyforge.org/](http://rubynode.rubyforge.org/)) you can do:

> > pp “3.times { puts ‘Ruby’ }”.parse\_to\_nodes.transform  
> > [:iter,  
> > {:var=\>false,  
> > :iter=\>[:call, {:args=\>false, :mid=\>:times, :recv=\>[:lit,  
> > {:lit=\>3}]}],  
> > :body=\>[:fcall, {:args=\>[:array, [[:str, {:lit=\>“Ruby”}]]],  
> > :mid=\>:puts}]}]  
> > =\> nil

The only thing that RubyNode or ParseTree won’t give you are the  
comments  
and whitespace in the code.

Dominik

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<div class="post-metadata">

**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 8:39pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/5 "2006-08-20T20:39:20Z")

</div>

Dominik B. wrote:

> I don’t know how to get Ripper working, but depending on what you want  
> to do, there might be better solutions like RubyNode or ParseTree.
> 
> –snip–

It’s what we currently use in FreeRIDE and I kinda like the way Ripper  
is used. Currently we only use it to aquire all methods/modules/classes.  
I guess I could look into working with a different parser but I’d prefer  
Ripper.

> The only thing that RubyNode or ParseTree won’t give you are the  
> comments and whitespace in the code.

That’s a bit of a letdown, nothing too serious. Probably easy to work  
around by wrapping the IO-source.  
Do you have any idea as to how memory-intensive either are?

Anyhow, thanks for the suggestion. I’ll look into it if Ripper takes too  
long to get running again.

Jonathan

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<div class="post-metadata">

**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 20, 2006, 10:09pm UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/6 "2006-08-20T22:09:31Z")

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On Sun, 20 Aug 2006 20:37:58 +0200, Jonathan M.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> I guess I could look into working with a different parser but I’d prefer  
> Ripper.

Ah okay, I thought you were trying to get Ripper running for the first  
time, for a new project. If you already have code then it might be  
easier  
to get Ripper working.

Anyway, here is some basic code to get methods and classes with RubyNode  
(it’s really basic and doesn’t work with nested classes, just to get you  
started):

Lets say we have this file:

$ cat test.rb  
class A  
def a  
1  
end  
def b  
2  
end  
end

class B  
def c  
3  
end  
end

Then this code:

require “rubynode”  
require “pp”

tree = IO.read(“test.rb”).parse\_to\_nodes.transform

def statements(block\_or\_single\_node)  
if block\_or\_single\_node.first == :block  
block\_or\_single\_node.last  
else  
[block\_or\_single\_node] # only one statement  
end  
end

statements(tree).each { |s|  
if s.first == :class  
p s.last[:cpath]  
statements(s.last[:body].last[:next]).each { |d|  
if d.first == :defn  
p d.last[:mid]  
pp d.last[:defn]  
end  
}  
end  
}

outputs:

[:colon2, {:mid=\>:A, :head=\>false}]  
:a  
[:scope,  
{:rval=\>false,  
:tbl=\>nil,  
:next=\>  
[:block, [[:args, {:cnt=\>0, :opt=\>false, :rest=\>-1}], [:lit,  
{:lit=\>1}]]]}]  
:b  
[:scope,  
{:rval=\>false,  
:tbl=\>nil,  
:next=\>  
[:block, [[:args, {:cnt=\>0, :opt=\>false, :rest=\>-1}], [:lit,  
{:lit=\>2}]]]}]  
[:colon2, {:mid=\>:B, :head=\>false}]  
:c  
[:scope,  
{:rval=\>false,  
:tbl=\>nil,  
:next=\>  
[:block, [[:args, {:cnt=\>0, :opt=\>false, :rest=\>-1}], [:lit,  
{:lit=\>3}]]]}]

> > The only thing that RubyNode or ParseTree won’t give you are the  
> > comments and whitespace in the code.
> 
> That’s a bit of a letdown, nothing too serious. Probably easy to work  
> around by wrapping the IO-source.  
> Do you have any idea as to how memory-intensive either are?

They both wrap Ruby’s internal NODEs. ParseTree converts them into  
s-expressions (nested arrays), RubyNode’s transform converts them to  
something similar (see above, a mix of arrays and hashes). So they use  
as  
much memory as their output needs.

If you really want to avoid the transformation to s-expressions then you  
can use RubyNodes directly without calling transform (see  
documentation),  
but that usually shouldn’t be necessary.

And btw. if you want to get the nodes without evaling the code then you  
currently have to use RubyNode, ParseTree doesn’t support that (yet).

Dominik

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**Author:** ![jonathan2000](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/fbc32d/32.png) [@jonathan2000](https://www.ruby-forum.com/u/jonathan2000)\
**Post date:** [August 21, 2006, 4:05am UTC](https://www.ruby-forum.com/t/ripper-and-ruby-1-8/65672/7 "2006-08-21T04:05:55Z")

</div>

Hi,

At Mon, 21 Aug 2006 00:39:40 +0900,  
Jonathan M. wrote in [ruby-talk:209505]:

> Thanks for the reply but I’m a bit at a loss here. I’m a total noob  
> regarding Ruby’s compilation process so I’m sorry if this is a stupid  
> question but if I have bison available why should I not be able to  
> compile Ripper against 1.8?

Ripper needs a bison specific feature, but parse.y in 1.8 can’t  
and doesn’t use it due to the compatibility.