module ExceptionsTree

# File lib/exceptions_tree/display.rb, line 11
def build_exceptions_tree
  exception_classes = []
  exceptions_tree = {}
  ObjectSpace.each_object(Class) do |klass|
    next unless klass.ancestors.include?(Exception)
    next if exception_classes.include?(klass)
    next if klass.superclass == SystemCallError # don't want ERRNO
    next if CLASSES_TO_IGNORE.include?(klass)
    exception_classes << klass
    klass.ancestors.delete_if {|e| CLASSES_TO_IGNORE.include?(e)}.
        reverse.inject(exceptions_tree) {|memo,klass2| memo[klass2] ||= {}}
  end
  exceptions_tree
end

# File lib/exceptions_tree/display.rb, line 7
def display_exceptions
  puts inspect_exceptions_tree(build_exceptions_tree, 0)
end

# File lib/exceptions_tree/display.rb, line 26
def inspect_exceptions_tree(tree, level)
  output = ''
  tree.keys.sort {|k1, k2| k1.name <=> k2.name}.each do |class_name|
    output += sprintf("%s%s\n", ('  ' * level), class_name)
    output += inspect_exceptions_tree(tree[class_name], level+1)
  end
  output
end