gistfile1.rb

#! /bin/ruby

def main argv
  n = (argv[0] || 2).to_i rescue 2
  m = (argv[1] || 20).to_i rescue 20
  g = n_gram n
  g.
    enum_for(:each_pair).
    lazy.
    sort_by {|k, v| -v }.
    first(m).
    each do |k, v|
    printf("%7d %s\n", v, k.join(' -> '))
  end
end

def n_gram n
  gram = Hash.new 0

  each_iseq_of all_sources do |i|
    each_sequence i.to_a do |a|
      insns = a.select{|j| Array === j }.map{|j| j[0] }
      insns.each_cons n do |c|
        gram[c] += 1
      end
    end
  end

  return gram
end

def all_sources
  return $LOADED_FEATURES.grep(/\.rb$/)
end

def each_iseq_of files
  files.each do |f|
    begin
      i = RubyVM::InstructionSequence.compile_file f, false
      yield i
    rescue Errno::ENOENT => e
      STDERR.printf "%s\n", e.message
    end
  end
end

def each_sequence a
  return unless a
  return unless a = a[13]
  a.each do |i|
    next unless Array === i
    j = case i[0]
        when :putiseq     then 1
        when :once        then 1
        when :defineclass then 2
        when :send        then 3
        when :invokesuper then 3
        else next
        end
    each_sequence i[j] do |b|
      yield b
    end
  end
  yield a
end

main ARGV

3-gram and 4-gram, also against redmine

% RUBYOPT=-vW0 RAILS_ENV=production bin/rails runner gistfile1.rb 3
ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin15]
No such file or directory @ rb_sysopen - thread.rb
  20688 putstring -> putobject -> putstring
  20449 putobject -> putstring -> putobject
  17734 putobject -> putiseq -> send
  17454 send -> pop -> putspecialobject
  16162 putspecialobject -> putobject -> putiseq
  15603 send -> branchunless -> jump
  15428 putiseq -> send -> pop
  14732 pop -> putspecialobject -> putobject
   9404 send -> pop -> putself
   7582 getlocal -> getlocal -> send
   7345 getlocal -> send -> send
   7167 branchunless -> jump -> getlocal
   6996 getlocal -> putobject -> send
   5532 putnil -> getconstant -> send
   5432 send -> setlocal -> getlocal
   5372 putobject -> send -> pop
   4994 send -> pop -> getlocal
   4976 putself -> send -> send
   4965 getlocal -> send -> leave
   4810 putself -> getlocal -> send
% RUBYOPT=-vW0 RAILS_ENV=production bin/rails runner gistfile1.rb 4
ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin15]
No such file or directory @ rb_sysopen - thread.rb
  20289 putobject -> putstring -> putobject -> putstring
  19993 putstring -> putobject -> putstring -> putobject
  16162 putspecialobject -> putobject -> putiseq -> send
  15428 putobject -> putiseq -> send -> pop
  14693 pop -> putspecialobject -> putobject -> putiseq
  14573 send -> pop -> putspecialobject -> putobject
  13355 putiseq -> send -> pop -> putspecialobject
   5515 send -> branchunless -> jump -> getlocal
   3871 getlocal -> send -> branchunless -> jump
   3710 putobject -> send -> branchunless -> jump
   3532 send -> pop -> putself -> putobject
   3305 send -> branchunless -> jump -> putself
   2980 putspecialobject -> putnil -> defineclass -> leave
   2942 send -> send -> branchunless -> jump
   2775 putself -> putstring -> send -> pop
   2485 putself -> putobject -> send -> pop
   2307 putstring -> putstring -> putstring -> putstring
   2287 putobject -> putiseq -> send -> leave
   2264 putstring -> send -> pop -> putself
   2134 putobject -> send -> pop -> putself