Consider the following structure:

    test.rb
    lib/A.treetop
    lib/B.treetop
    lib/AB.treetop
    lib/all.rb

And the sources for the files

    # test.rb
    require File.dirname(__FILE__) + "/lib/all"

    # lib/A.treetop
    grammar A
      include AB
    end

    # lib/B.treetop
    grammar B
      include AB
    end

    # lib/AB.treetop
    grammar AB
      include A
      include B
    end

    # lib/all.rb
    require 'treetop'

    require File.dirname(__FILE__) + '/A'
    require File.dirname(__FILE__) + '/B'
    require File.dirname(__FILE__) + '/AB'

It's very obvious that I've introduced a circular dependency.

Now when I run test.rb

    ruby test.rb

I receive the following error:

    /home/eric/.rvm/gems/ruby-1.9.2-rc2/gems/treetop-1.4.8/lib/treetop/
compiler/grammar_compiler.rb:42:in `class_eval': uninitialized
constant A::AB (NameError)
    ....

meaning that it could not include the 'AB' grammar in the 'A' grammar
since it's after it in the 'all.rb' file.

However, this circular dependency is necessary.

Consider this pseudo-grammar where it would be applicable:

    # Statement file
    include ForStatement
    include SwitchStatement
    statement -> for_statement / switch_statement / other_statement

    # ForStatement file
    include Statement
    for_statement -> 'for (' expr ')' statement

As you can see, the for loop can contain other statements inside it.
But I cannot accomplish this unless all the rules are in the same
file.

Can someone please point me in the right direction on how to
accomplish this if it's even possible?