/gist:7ce9cb03b5bc6cfe6f96ec6c4940602e

## 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
	#! /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