Generating dot files from Ruby code.

gistfile1.rb

require 'ap'
require 'ripper'

CLASS_TEXT = "class A; end; class B; end"
CLASS_SEXP = Ripper.sexp(CLASS_TEXT)

BIG_TEXT = "class A; def a; @a = b; end; def b; @d = a; @e = a; end; end; module B; def b; end; end"
BIG_SEXP = Ripper.sexp(BIG_TEXT)

FIELDS_TEXT = "class A; def a; @a = @b; end; end"
FIELDS_SEXP = Ripper.sexp(FIELDS_TEXT)

class Object
  def ary?; is_a? Array; end
  def is_str?; is_a? String; end

  def nonempty_ary?
    ary? && (not empty?)
  end
end

def sexp_select sexp, symbols
  (1..(max_nesting_level = 20)).map {|n| sexp.flatten(n)
                                             .select(&:nonempty_ary?)
                                             .select {|e| symbols.include? e[0] }}
                               .select(&:nonempty_ary?)
                               .flatten(1)
end


class MethodNode
  def initialize sexp
    @expression = sexp
  end

  def name
    @name ||= @expression.flatten.select(&:is_str?).first
  end

  def body_without_method_name
    @expression.flatten.drop(3)
  end

  def dependencies names_in_scope
    names_in_scope & body_without_method_name.select(&:is_str?)
  end

end


class ClassNode
  def initialize sexp
    @expression = sexp
  end

  def field_names
    @field_names ||= @expression.flatten
                                .each_cons(2)
                                .select {|marker, _| marker == :@ivar }
                                .map {|_,name| name }
  end

  def method_names
    method_nodes.keys
  end

  def names
    @names ||= field_names + method_names
  end

  def method_nodes
    @method_nodes ||= Hash[sexp_select(@expression, [:def]).map {|sexp| MethodNode.new(sexp) }
                                                           .map {|mn| [mn.name, mn] }]
  end

  def dependencies
    @dependencies ||= method_nodes.map {|n,mn| [n, mn.dependencies(names)] }
  end
end

def q string
  "\"#{string}\""
end

def dot_names names
  "  { node [shape=ellipse] #{names.map(&:to_s).map {|s| q(s) }.join(' ')}}"
end

def dot_method_dependencies source_name, target_names
  target_names.map {|tn| "  #{q(source_name)} -> #{q(tn)}" }.join($/)
end


def dot_class class_node
<<-TEXT
digraph {
#{dot_names(class_node.names)}
#{class_node.dependencies.map {|source, targets| dot_method_dependencies(source, targets)}.join($/)}
}
TEXT
end

CS = sexp_select(BIG_SEXP, [:class, :module]).map { |e| ClassNode.new(e) }