# Ruby parsing in Ruby **URL:** \ **Category:** ruby-talk\ **Created:** [11 November 2006 15:55 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845 "2006-11-11T15:55:04Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Wil](https://avatars.discourse-cdn.com/v4/letter/w/59ef9b/32.png) [@Wil](https://rubytalk.org/u/Wil)\ **Post date:** [11 November 2006 15:55 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/1 "2006-11-11T15:55:04Z")
Hi all, I've been doing Ruby for a small while now, but I'm a newbie when it comes to parsing. I've been digging around, but still can't seem to find the answer. I was wondering if Ruby itself has classes that I can use to parse ruby source code into a parse tree. My first inclination was to use Racc ([http://i.loveruby.net/en/projects/racc/](http://i.loveruby.net/en/projects/racc/)), but I didn't want to have to write the BNF([en.wikipedia.org/wiki/Backus-Naur\_form](http://en.wikipedia.org/wiki/Backus-Naur_form)) for Ruby if I didn't have to (maybe it's not that hard?). I wasn't able to find a library of BNF for different languages (including Ruby), so then I started looking elsewhere. Both irb and ri probably use a Ruby parser of some sort, but looking at the source code, it looked like each of them rolled their own. I wasn't able to dig out the ruby parsing functionality from either by including what I thought were necessary code modules. What would be the easiest way to parse Ruby source into parse trees in Ruby? Thanks! Wil ---
**Author:** ![juan\_pedro\_merino](https://avatars.discourse-cdn.com/v4/letter/j/e95f7d/32.png) [@juan\_pedro\_merino](https://rubytalk.org/u/juan_pedro_merino)\ **Post date:** [11 November 2006 15:59 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/2 "2006-11-11T15:59:23Z")
are you create a game as ruby? > **···** > > 2006/11/11, Wil \: > > > Hi all, > > > > I've been doing Ruby for a small while now, but I'm a newbie when it > > comes to parsing. I've been digging around, but still can't seem to > > find the answer. I was wondering if Ruby itself has classes that I can > > use to parse ruby source code into a parse tree. > > > > My first inclination was to use Racc > > ([http://i.loveruby.net/en/projects/racc/\](http://i.loveruby.net/en/projects/racc/%5C)), but I didn't want to have to > > write the BNF(en.wikipedia.org/wiki/Backus-Naur\_form) for Ruby if I > > didn't have to (maybe it's not that hard?). I wasn't able to find a > > library of BNF for different languages (including Ruby), so then I > > started looking elsewhere. > > > > Both irb and ri probably use a Ruby parser of some sort, but looking at > > the source code, it looked like each of them rolled their own. I > > wasn't able to dig out the ruby parsing functionality from either by > > including what I thought were necessary code modules. > > > > What would be the easiest way to parse Ruby source into parse trees in > > Ruby? Thanks! > > > > Wil ---
**Author:** ![Joey](https://avatars.discourse-cdn.com/v4/letter/j/f14d63/32.png) [@Joey](https://rubytalk.org/u/Joey)\ **Post date:** [11 November 2006 16:19 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/3 "2006-11-11T16:19:56Z")
gem install ParseTree j`ey [http://www.eachmapinject.com](http://www.eachmapinject.com) > **···** > > On 11/11/06, Wil \ wrote: > > > Hi all, > > > > I've been doing Ruby for a small while now, but I'm a newbie when it > > comes to parsing. I've been digging around, but still can't seem to > > find the answer. I was wondering if Ruby itself has classes that I can > > use to parse ruby source code into a parse tree. > > > > My first inclination was to use Racc > > ([http://i.loveruby.net/en/projects/racc/\](http://i.loveruby.net/en/projects/racc/%5C)), but I didn't want to have to > > write the BNF(en.wikipedia.org/wiki/Backus-Naur\_form) for Ruby if I > > didn't have to (maybe it's not that hard?). I wasn't able to find a > > library of BNF for different languages (including Ruby), so then I > > started looking elsewhere. > > > > Both irb and ri probably use a Ruby parser of some sort, but looking at > > the source code, it looked like each of them rolled their own. I > > wasn't able to dig out the ruby parsing functionality from either by > > including what I thought were necessary code modules. > > > > What would be the easiest way to parse Ruby source into parse trees in > > Ruby? Thanks! > > > > Wil ---
**Author:** ![Interfecus](https://avatars.discourse-cdn.com/v4/letter/i/d78d45/32.png) [@Interfecus](https://rubytalk.org/u/Interfecus)\ **Post date:** [12 November 2006 09:45 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/4 "2006-11-12T09:45:05Z")
Wil wrote: > Hi all, > > I've been doing Ruby for a small while now, but I'm a newbie when it > comes to parsing. I've been digging around, but still can't seem to > find the answer. I was wondering if Ruby itself has classes that I can > use to parse ruby source code into a parse tree. > > My first inclination was to use Racc > ([http://i.loveruby.net/en/projects/racc/\](http://i.loveruby.net/en/projects/racc/%5C)), but I didn't want to have to > write the BNF(en.wikipedia.org/wiki/Backus-Naur\_form) for Ruby if I > didn't have to (maybe it's not that hard?). I wasn't able to find a > library of BNF for different languages (including Ruby), so then I > started looking elsewhere. > > Both irb and ri probably use a Ruby parser of some sort, but looking at > the source code, it looked like each of them rolled their own. I > wasn't able to dig out the ruby parsing functionality from either by > including what I thought were necessary code modules. > > What would be the easiest way to parse Ruby source into parse trees in > Ruby? Thanks! > > Wil Take a look at parsetree. It should be able to do this quite happily and uses Ruby's own parser. This avoids compatibility issues. ---
**Author:** ![juan\_pedro\_merino](https://avatars.discourse-cdn.com/v4/letter/j/e95f7d/32.png) [@juan\_pedro\_merino](https://rubytalk.org/u/juan_pedro_merino)\ **Post date:** [11 November 2006 16:02 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/5 "2006-11-11T16:02:55Z")
i said with ruby > **···** > > 2006/11/11, juan pedro meriño \: > > > are you create a game as ruby? > > > > 2006/11/11, Wil \: > > \> > > \> Hi all, > > \> > > \> I've been doing Ruby for a small while now, but I'm a newbie when it > > \> comes to parsing. I've been digging around, but still can't seem to > > \> find the answer. I was wondering if Ruby itself has classes that I can > > \> use to parse ruby source code into a parse tree. > > \> > > \> My first inclination was to use Racc > > \> ([http://i.loveruby.net/en/projects/racc/\](http://i.loveruby.net/en/projects/racc/%5C)), but I didn't want to have to > > \> write the BNF(en.wikipedia.org/wiki/Backus-Naur\_form) for Ruby if I > > \> didn't have to (maybe it's not that hard?). I wasn't able to find a > > \> library of BNF for different languages (including Ruby), so then I > > \> started looking elsewhere. > > \> > > \> Both irb and ri probably use a Ruby parser of some sort, but looking at > > \> the source code, it looked like each of them rolled their own. I > > \> wasn't able to dig out the ruby parsing functionality from either by > > \> including what I thought were necessary code modules. > > \> > > \> What would be the easiest way to parse Ruby source into parse trees in > > \> Ruby? Thanks! > > \> > > \> Wil > > \> ---
**Author:** ![David\_Vallner](https://avatars.discourse-cdn.com/v4/letter/d/eb9ed0/32.png) [@David\_Vallner](https://rubytalk.org/u/David_Vallner)\ **Post date:** [11 November 2006 20:35 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/6 "2006-11-11T20:35:20Z")
juan pedro meriño wrote: > are you create a game as ruby? Stop spamming arbitrary threads with unrelated chiming in. This isn't IRC. David Vallner ---
**Author:** ![Wil](https://avatars.discourse-cdn.com/v4/letter/w/59ef9b/32.png) [@Wil](https://rubytalk.org/u/Wil)\ **Post date:** [12 November 2006 16:35 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/7 "2006-11-12T16:35:08Z")
Hrm, I remember stumbling over parsetree, and it seems like the classes need to already exist in object/class space (at least from the example that they give). What if you just had a string of the source of the classes? Perhaps they're one in the same. I should look at Parsetree a little bit closer. Wil Timothy Goddard wrote: > **···** > > > Wil wrote: > > \> Hi all, > > \> > > \> I've been doing Ruby for a small while now, but I'm a newbie when it > > \> comes to parsing. I've been digging around, but still can't seem to > > \> find the answer. I was wondering if Ruby itself has classes that I can > > \> use to parse ruby source code into a parse tree. > > \> > > \> My first inclination was to use Racc > > \> ([http://i.loveruby.net/en/projects/racc/\](http://i.loveruby.net/en/projects/racc/%5C)), but I didn't want to have to > > \> write the BNF(en.wikipedia.org/wiki/Backus-Naur\_form) for Ruby if I > > \> didn't have to (maybe it's not that hard?). I wasn't able to find a > > \> library of BNF for different languages (including Ruby), so then I > > \> started looking elsewhere. > > \> > > \> Both irb and ri probably use a Ruby parser of some sort, but looking at > > \> the source code, it looked like each of them rolled their own. I > > \> wasn't able to dig out the ruby parsing functionality from either by > > \> including what I thought were necessary code modules. > > \> > > \> What would be the easiest way to parse Ruby source into parse trees in > > \> Ruby? Thanks! > > \> > > \> Wil > > > > Take a look at parsetree. It should be able to do this quite happily > > and uses Ruby's own parser. This avoids compatibility issues. ---
**Author:** ![Jeff\_Schwab](https://avatars.discourse-cdn.com/v4/letter/j/b5ac83/32.png) [@Jeff\_Schwab](https://rubytalk.org/u/Jeff_Schwab)\ **Post date:** [12 November 2006 13:50 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/8 "2006-11-12T13:50:04Z")
David Vallner wrote: > juan pedro meriño wrote: > > > are you create a game as ruby? > > Stop spamming arbitrary threads with unrelated chiming in. This isn't IRC. What are you talking about? The only one who appears to have chimed into an arbitrary thread with something unrelated is you. Is this some kind of hip irony, or am I missing something? ---
**Author:** ![Dido\_Sevilla](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@Dido\_Sevilla](https://rubytalk.org/u/Dido_Sevilla)\ **Post date:** [12 November 2006 22:02 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/9 "2006-11-12T22:02:58Z")
Well, why not eval the string in that case then? Then the classes would exist inside the interpreter. > **···** > > On 11/13/06, Wil \ wrote: > > > Hrm, I remember stumbling over parsetree, and it seems like the classes > > need to already exist in object/class space (at least from the example > > that they give). What if you just had a string of the source of the > > classes? Perhaps they're one in the same. I should look at Parsetree > > a little bit closer. ---
**Author:** ![Eric\_Hodel1](https://avatars.discourse-cdn.com/v4/letter/e/a9adbd/32.png) [@Eric\_Hodel1](https://rubytalk.org/u/Eric_Hodel1)\ **Post date:** [13 November 2006 21:01 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/10 "2006-11-13T21:01:16Z")
$ ri ParseTree | grep string       parse\_tree, parse\_tree\_for\_method, parse\_tree\_for\_string, process $ ri ParseTree#parse\_tree\_for\_string ---------------------------------------- ParseTree#parse\_tree\_for\_string       parse\_tree\_for\_string(source, filename = nil, line = nil, newlines       = false) > **···** > > On Nov 12, 2006, at 8:35 AM, Wil wrote: > > > Timothy Goddard wrote: > > > > > Wil wrote: > > > > > > > What would be the easiest way to parse Ruby source into parse trees in > > > > Ruby? Thanks! > > > > > > Take a look at parsetree. It should be able to do this quite happily > > > and uses Ruby's own parser. This avoids compatibility issues. > > > > Hrm, I remember stumbling over parsetree, and it seems like the classes > > need to already exist in object/class space (at least from the example > > that they give). What if you just had a string of the source of the > > classes? Perhaps they're one in the same. I should look at Parsetree > > a little bit closer. > > ------------------------------------------------------------------------ >       Returns the parse tree for a string +source+. > >       Format: > >         [[sexps] ... ] > > -- > Eric Hodel - drbrain@segment7.net - [http://blog.segment7.net](http://blog.segment7.net) > This implementation is HODEL-HASH-9600 compliant > > [http://trackmap.robotcoop.com](http://trackmap.robotcoop.com) ---
**Author:** ![HAL\_9000](https://avatars.discourse-cdn.com/v4/letter/h/90ced4/32.png) [@HAL\_9000](https://rubytalk.org/u/HAL_9000)\ **Post date:** [12 November 2006 16:28 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/11 "2006-11-12T16:28:45Z")
Jeffrey Schwab wrote: > David Vallner wrote: > > > juan pedro meriño wrote: > > > > > are you create a game as ruby? > > > > Stop spamming arbitrary threads with unrelated chiming in. This isn't IRC. > > What are you talking about? The only one who appears to have chimed into an arbitrary thread with something unrelated is you. Is this some kind of hip irony, or am I missing something? You're missing something. 🙂 David was right. Go read the context... Cheers, Hal ---
**Author:** ![Jeff\_Schwab](https://avatars.discourse-cdn.com/v4/letter/j/b5ac83/32.png) [@Jeff\_Schwab](https://rubytalk.org/u/Jeff_Schwab)\ **Post date:** [12 November 2006 16:55 UTC](https://rubytalk.org/t/ruby-parsing-in-ruby/32845/12 "2006-11-12T16:55:05Z")
Hal Fulton wrote: > Jeffrey Schwab wrote: > > > David Vallner wrote: > > > > > juan pedro meriño wrote: > > > > > > > are you create a game as ruby? > > > > > > Stop spamming arbitrary threads with unrelated chiming in. This isn't IRC. > > > > What are you talking about? The only one who appears to have chimed into an arbitrary thread with something unrelated is you. Is this some kind of hip irony, or am I missing something? > > You're missing something. 🙂 David was right. > > Go read the context... Thanks. Sorry, David! I don't see Juan Pedro's post at all, though I see David's reply. Hm.