module PP::PPMethods - pp: Ruby Standard Library Documentation

check_inspect_key(id) click to toggle source

Check whether the object_id id is in the current buffer of objects to be pretty printed. Used to break cycles in chains of objects to be pretty printed.

# File pp.rb, line 169
def check_inspect_key(id)
  Thread.current[:__recursive_key__] &&
  Thread.current[:__recursive_key__][:inspect] &&
  Thread.current[:__recursive_key__][:inspect].include?(id)
end

comma_breakable() click to toggle source

A convenience method which is same as follows:

text ','
breakable

# File pp.rb, line 232
def comma_breakable
  text ','
  breakable
end

guard_inspect_key() { || ... } click to toggle source

Yields to a block and preserves the previous set of objects being printed.

# File pp.rb, line 147
def guard_inspect_key
  if Thread.current[:__recursive_key__] == nil
    Thread.current[:__recursive_key__] = {}.compare_by_identity
  end

  if Thread.current[:__recursive_key__][:inspect] == nil
    Thread.current[:__recursive_key__][:inspect] = {}.compare_by_identity
  end

  save = Thread.current[:__recursive_key__][:inspect]

  begin
    Thread.current[:__recursive_key__][:inspect] = {}.compare_by_identity
    yield
  ensure
    Thread.current[:__recursive_key__][:inspect] = save
  end
end

object_address_group(obj, &block) click to toggle source

A convenience method, like object_group, but also reformats the Object’s object_id.

# File pp.rb, line 222
def object_address_group(obj, &block)
  str = Kernel.instance_method(:to_s).bind_call(obj)
  str.chomp!('>')
  group(1, str, '>', &block)
end

object_group(obj) { || ... } click to toggle source

A convenience method which is same as follows:

group(1, '#<' + obj.class.name, '>') { ... }

# File pp.rb, line 216
def object_group(obj, &block) # :yield:
  group(1, '#<' + obj.class.name, '>', &block)
end

pop_inspect_key(id) click to toggle source

Removes an object from the set of objects being pretty printed.

# File pp.rb, line 182
def pop_inspect_key(id)
  Thread.current[:__recursive_key__][:inspect].delete id
end

pp(obj) click to toggle source

Adds obj to the pretty printing buffer using Object#pretty_print or Object#pretty_print_cycle.

Object#pretty_print_cycle is used when obj is already printed, a.k.a the object reference chain has a cycle.

# File pp.rb, line 191
def pp(obj)
  # If obj is a Delegator then use the object being delegated to for cycle
  # detection
  obj = obj.__getobj__ if defined?(::Delegator) and ::Delegator === obj

  if check_inspect_key(obj)
    group {obj.pretty_print_cycle self}
    return
  end

  begin
    push_inspect_key(obj)
    group do
      obj.pretty_print self
    rescue NoMethodError
      text Kernel.instance_method(:inspect).bind_call(obj)
    end
  ensure
    pop_inspect_key(obj) unless PP.sharing_detection
  end
end

pp_hash(obj) click to toggle source

A pretty print for a Hash

# File pp.rb, line 291
def pp_hash(obj)
  group(1, '{', '}') {
    seplist(obj, nil, :each_pair) {|k, v|
      group {
        pp_hash_pair k, v
      }
    }
  }
end

pp_hash_pair(k, v) click to toggle source

A pretty print for a pair of Hash

# File pp.rb, line 303
def pp_hash_pair(k, v)
  if Symbol === k
    sym_s = k.inspect
    if sym_s[1].match?(/["$@!]/) || sym_s[-1].match?(/[%&*+\-\/<=>@\]^`|~]/)
      text "#{k.to_s.inspect}:"
    else
      text "#{k}:"
    end
  else
    pp k
    text ' '
    text '=>'
  end
  group(1) {
    breakable
    pp v
  }
end

pp_object(obj) click to toggle source

A present standard failsafe for pretty printing any given Object

# File pp.rb, line 275
def pp_object(obj)
  object_address_group(obj) {
    seplist(obj.pretty_print_instance_variables, lambda { text ',' }) {|v|
      breakable
      v = v.to_s if Symbol === v
      text v
      text '='
      group(1) {
        breakable ''
        pp(obj.instance_eval(v))
      }
    }
  }
end

push_inspect_key(id) click to toggle source

Adds the object_id id to the set of objects being pretty printed, so as to not repeat objects.

# File pp.rb, line 177
def push_inspect_key(id)
  Thread.current[:__recursive_key__][:inspect][id] = true
end

seplist(list, sep=nil, iter_method=:each) { |element| ... } click to toggle source

Adds a separated list. The list is separated by comma with breakable space, by default.

seplist iterates the list using iter_method. It yields each object to the block given for seplist. The procedure separator_proc is called between each yields.

If the iteration is zero times, separator_proc is not called at all.

If separator_proc is nil or not given, +lambda { comma_breakable }+ is used. If iter_method is not given, :each is used.

For example, following 3 code fragments has similar effect.

q.seplist([1,2,3]) {|v| xxx v }

q.seplist([1,2,3], lambda { q.comma_breakable }, :each) {|v| xxx v }

xxx 1
q.comma_breakable
xxx 2
q.comma_breakable
xxx 3

# File pp.rb, line 261
def seplist(list, sep=nil, iter_method=:each) # :yield: element
  sep ||= lambda { comma_breakable }
  first = true
  list.__send__(iter_method) {|*v|
    if first
      first = false
    else
      sep.call
    end
    RUBY_VERSION >= "3.0" ? yield(*v, **{}) : yield(*v)
  }
end