# == Pretty-printer for Ruby objects.
#
# = Which seems better?
#
# non-pretty-printed output by #p is:
# #<PP:0x81fedf0 @genspace=#<Proc:0x81feda0>, @group_queue=#<PrettyPrint::GroupQueue:0x81fed3c @queue=[[#<PrettyPrint::Group:0x81fed78 @breakables=[], @depth=0, @break=false>], []]>, @buffer=[], @newline="\n", @group_stack=[#<PrettyPrint::Group:0x81fed78 @breakables=[], @depth=0, @break=false>], @buffer_width=0, @indent=0, @maxwidth=79, @output_width=2, @output=#<IO:0x8114ee4>>
#
# pretty-printed output by #pp is:
# #<PP:0x81fedf0
# @buffer=[],
# @buffer_width=0,
# @genspace=#<Proc:0x81feda0>,
# @group_queue=
# #<PrettyPrint::GroupQueue:0x81fed3c
# @queue=
# [[#<PrettyPrint::Group:0x81fed78 @break=false, @breakables=[], @depth=0>],
# []]>,
# @group_stack=
# [#<PrettyPrint::Group:0x81fed78 @break=false, @breakables=[], @depth=0>],
# @indent=0,
# @maxwidth=79,
# @newline="\n",
# @output=#<IO:0x8114ee4>,
# @output_width=2>
#
# I like the latter. If you do too, this library is for you.
#
# = Usage
#
# pp(obj)
#
# output +obj+ to +$>+ in pretty printed format.
#
# It returns +nil+.
#
# = Output Customization
# To define your customized pretty printing function for your classes,
# redefine a method #pretty_print(+pp+) in the class.
# It takes an argument +pp+ which is an instance of the class PP.
# The method should use PP#text, PP#breakable, PP#nest, PP#group and
# PP#pp to print the object.
#
# = Author
# Tanaka Akira <akr@m17n.org>
require 'prettyprint'
module Kernel
# returns a pretty printed object as a string.
def pretty_inspect
PP.pp(self, '')
end
private
# prints arguments in pretty form.
#
# pp returns nil.
def pp(*objs) # :doc:
objs.each {|obj|
PP.pp(obj)
}
nil
end
module_function :pp
end
class PP < PrettyPrint
# Outputs +obj+ to +out+ in pretty printed format of
# +width+ columns in width.
#
# If +out+ is omitted, +$>+ is assumed.
# If +width+ is omitted, 79 is assumed.
#
# PP.pp returns +out+.
def PP.pp(obj, out=$>, width=79)
q = PP.new(out, width)
q.guard_inspect_key {q.pp obj}
q.flush
#$pp = q
out << "\n"
end
# Outputs +obj+ to +out+ like PP.pp but with no indent and
# newline.
#
# PP.singleline_pp returns +out+.
def PP.singleline_pp(obj, out=$>)
q = SingleLine.new(out)
q.guard_inspect_key {q.pp obj}
q.flush
out
end
# :stopdoc:
def PP.mcall(obj, mod, meth, *args, &block)
mod.instance_method(meth).bind(obj).call(*args, &block)
end
# :startdoc:
@sharing_detection = false
class << self
# Returns the sharing detection flag as a boolean value.
# It is false by default.
attr_accessor :sharing_detection
end
module PPMethods
InspectKey = :__inspect_key__
def guard_inspect_key
if Thread.current[InspectKey] == nil
Thread.current[InspectKey] = []
end
save = Thread.current[InspectKey]
begin
Thread.current[InspectKey] = []
yield
ensure
Thread.current[InspectKey] = save
end
end
# 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.
def pp(obj)
id = obj.__id__
if Thread.current[InspectKey].include? id
group {obj.pretty_print_cycle self}
return
end
begin
Thread.current[InspectKey] << id
group {obj.pretty_print self}
ensure
Thread.current[InspectKey].pop unless PP.sharing_detection
end
end
# A convenience method which is same as follows:
#
# group(1, '#<' + obj.class.name, '>') { ... }
def object_group(obj, &block) # :yield:
group(1, '#<' + obj.class.name, '>', &block)
end
def object_address_group(obj, &block)
id = "%x" % (obj.__id__ * 2)
id.sub!(/\Af(?=[[:xdigit:]]{2}+\z)/, '') if id.sub!(/\A\.\./, '')
group(1, "\#<#{obj.class}:0x#{id}", '>', &block)
end
# A convenience method which is same as follows:
#
# text ','
# breakable
def comma_breakable
text ','
breakable
end
# 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 { comma_breakable }, :each) {|v| xxx v }
#
# xxx 1
# q.comma_breakable
# xxx 2
# q.comma_breakable
# xxx 3
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
yield(*v)
}
end
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
def pp_hash(obj)
group(1, '{', '}') {
seplist(obj, nil, :each_pair) {|k, v|
group {
pp k
text '=>'
group(1) {
breakable ''
pp v
}
}
}
}
end
end
include PPMethods
class SingleLine < PrettyPrint::SingleLine
include PPMethods
end
module ObjectMixin
# 1. specific pretty_print
# 2. specific inspect
# 3. specific to_s if instance variable is empty
# 4. generic pretty_print
# A default pretty printing method for general objects.
# It calls #pretty_print_instance_variables to list instance variables.
#
# If +self+ has a customized (redefined) #inspect method,
# the result of self.inspect is used but it obviously has no
# line break hints.
#
# This module provides predefined #pretty_print methods for some of
# the most commonly used built-in classes for convenience.
def pretty_print(q)
if /\(Kernel\)#/ !~ method(:inspect).inspect
q.text self.inspect
elsif /\(Kernel\)#/ !~ method(:to_s).inspect && instance_variables.empty?
q.text self.to_s
else
q.pp_object(self)
end
end
# A default pretty printing method for general objects that are
# detected as part of a cycle.
def pretty_print_cycle(q)
q.object_address_group(self) {
q.breakable
q.text '...'
}
end
# Returns a sorted array of instance variable names.
#
# This method should return an array of names of instance variables as symbols or strings as:
# +[:@a, :@b]+.
def pretty_print_instance_variables
instance_variables.sort
end
# Is #inspect implementation using #pretty_print.
# If you implement #pretty_print, it can be used as follows.
#
# alias inspect pretty_print_inspect
#
# However, doing this requires that every class that #inspect is called on
# implement #pretty_print, or a RuntimeError will be raised.
def pretty_print_inspect
if /\(PP::ObjectMixin\)#/ =~ method(:pretty_print).inspect
raise "pretty_print is not overridden for #{self.class}"
end
PP.singleline_pp(self, '')
end
end
end
class Array
def pretty_print(q)
q.group(1, '[', ']') {
q.seplist(self) {|v|
q.pp v
}
}
end
def pretty_print_cycle(q)
q.text(empty? ? '[]' : '[...]')
end
end
class Hash
def pretty_print(q)
q.pp_hash self
end
def pretty_print_cycle(q)
q.text(empty? ? '{}' : '{...}')
end
end
class << ENV
def pretty_print(q)
q.pp_hash self
end
end
class Struct
def pretty_print(q)
q.group(1, '#<struct ' + PP.mcall(self, Kernel, :class).name, '>') {
q.seplist(PP.mcall(self, Struct, :members), lambda { q.text "," }) {|member|
q.breakable
q.text member.to_s
q.text '='
q.group(1) {
q.breakable ''
q.pp self[member]
}
}
}
end
def pretty_print_cycle(q)
q.text sprintf("#<struct %s:...>", PP.mcall(self, Kernel, :class).name)
end
end
class Range
def pretty_print(q)
q.pp self.begin
q.breakable ''
q.text(self.exclude_end? ? '...' : '..')
q.breakable ''
q.pp self.end
end
end
class File
class Stat
def pretty_print(q)
require 'etc.so'
q.object_group(self) {
q.breakable
q.text sprintf("dev=0x%x", self.dev); q.comma_breakable
q.text "ino="; q.pp self.ino; q.comma_breakable
q.group {
m = self.mode
q.text sprintf("mode=0%o", m)
q.breakable
q.text sprintf("(%s %c%c%c%c%c%c%c%c%c)",
self.ftype,
(m & 0400 == 0 ? ?- : ?r),
(m & 0200 == 0 ? ?- : ?w),
(m & 0100 == 0 ? (m & 04000 == 0 ? ?- : ?S) :
(m & 04000 == 0 ? ?x : ?s)),
(m & 0040 == 0 ? ?- : ?r),
(m & 0020 == 0 ? ?- : ?w),
(m & 0010 == 0 ? (m & 02000 == 0 ? ?- : ?S) :
(m & 02000 == 0 ? ?x : ?s)),
(m & 0004 == 0 ? ?- : ?r),
(m & 0002 == 0 ? ?- : ?w),
(m & 0001 == 0 ? (m & 01000 == 0 ? ?- : ?T) :
(m & 01000 == 0 ? ?x : ?t)))
}
q.comma_breakable
q.text "nlink="; q.pp self.nlink; q.comma_breakable
q.group {
q.text "uid="; q.pp self.uid
begin
pw = Etc.getpwuid(self.uid)
rescue ArgumentError
end
if pw
q.breakable; q.text "(#{pw.name})"
end
}
q.comma_breakable
q.group {
q.text "gid="; q.pp self.gid
begin
gr = Etc.getgrgid(self.gid)
rescue ArgumentError
end
if gr
q.breakable; q.text "(#{gr.name})"
end
}
q.comma_breakable
q.group {
q.text sprintf("rdev=0x%x", self.rdev)
q.breakable
q.text sprintf('(%d, %d)', self.rdev_major, self.rdev_minor)
}
q.comma_breakable
q.text "size="; q.pp self.size; q.comma_breakable
q.text "blksize="; q.pp self.blksize; q.comma_breakable
q.text "blocks="; q.pp self.blocks; q.comma_breakable
q.group {
t = self.atime
q.text "atime="; q.pp t
q.breakable; q.text "(#{t.tv_sec})"
}
q.comma_breakable
q.group {
t = self.mtime
q.text "mtime="; q.pp t
q.breakable; q.text "(#{t.tv_sec})"
}
q.comma_breakable
q.group {
t = self.ctime
q.text "ctime="; q.pp t
q.breakable; q.text "(#{t.tv_sec})"
}
}
end
end
end
class MatchData
def pretty_print(q)
q.object_group(self) {
q.breakable
q.seplist(1..self.size, lambda { q.breakable }) {|i|
q.pp self[i-1]
}
}
end
end
class Object
include PP::ObjectMixin
end
[Numeric, Symbol, FalseClass, TrueClass, NilClass, Module].each {|c|
c.class_eval {
def pretty_print_cycle(q)
q.text inspect
end
}
}
[Numeric, FalseClass, TrueClass, Module].each {|c|
c.class_eval {
def pretty_print(q)
q.text inspect
end
}
}
# :enddoc:
if __FILE__ == $0
require 'test/unit'
class PPTest < Test::Unit::TestCase
def test_list0123_12
assert_equal("[0, 1, 2, 3]\n", PP.pp([0,1,2,3], '', 12))
end
def test_list0123_11
assert_equal("[0,\n 1,\n 2,\n 3]\n", PP.pp([0,1,2,3], '', 11))
end
OverriddenStruct = Struct.new("OverriddenStruct", :members, :class)
def test_struct_override_members # [ruby-core:7865]
a = OverriddenStruct.new(1,2)
assert_equal("#<struct Struct::OverriddenStruct members=1, class=2>\n", PP.pp(a, ''))
end
end
class HasInspect
def initialize(a)
@a = a
end
def inspect
return "<inspect:#{@a.inspect}>"
end
end
class HasPrettyPrint
def initialize(a)
@a = a
end
def pretty_print(q)
q.text "<pretty_print:"
q.pp @a
q.text ">"
end
end
class HasBoth
def initialize(a)
@a = a
end
def inspect
return "<inspect:#{@a.inspect}>"
end
def pretty_print(q)
q.text "<pretty_print:"
q.pp @a
q.text ">"
end
end
class PrettyPrintInspect < HasPrettyPrint
alias inspect pretty_print_inspect
end
class PrettyPrintInspectWithoutPrettyPrint
alias inspect pretty_print_inspect
end
class PPInspectTest < Test::Unit::TestCase
def test_hasinspect
a = HasInspect.new(1)
assert_equal("<inspect:1>\n", PP.pp(a, ''))
end
def test_hasprettyprint
a = HasPrettyPrint.new(1)
assert_equal("<pretty_print:1>\n", PP.pp(a, ''))
end
def test_hasboth
a = HasBoth.new(1)
assert_equal("<pretty_print:1>\n", PP.pp(a, ''))
end
def test_pretty_print_inspect
a = PrettyPrintInspect.new(1)
assert_equal("<pretty_print:1>", a.inspect)
a = PrettyPrintInspectWithoutPrettyPrint.new
assert_raise(RuntimeError) { a.inspect }
end
def test_proc
a = proc {1}
assert_equal("#{a.inspect}\n", PP.pp(a, ''))
end
def test_to_s_with_iv
a = Object.new
def a.to_s() "aaa" end
a.instance_eval { @a = nil }
result = PP.pp(a, '')
assert_equal("#{a.inspect}\n", result)
assert_match(/\A#<Object.*>\n\z/m, result)
a = 1.0
a.instance_eval { @a = nil }
result = PP.pp(a, '')
assert_equal("#{a.inspect}\n", result)
end
def test_to_s_without_iv
a = Object.new
def a.to_s() "aaa" end
result = PP.pp(a, '')
assert_equal("#{a.inspect}\n", result)
assert_equal("aaa\n", result)
end
end
class PPCycleTest < Test::Unit::TestCase
def test_array
a = []
a << a
assert_equal("[[...]]\n", PP.pp(a, ''))
assert_equal("#{a.inspect}\n", PP.pp(a, ''))
end
def test_hash
a = {}
a[0] = a
assert_equal("{0=>{...}}\n", PP.pp(a, ''))
assert_equal("#{a.inspect}\n", PP.pp(a, ''))
end
S = Struct.new("S", :a, :b)
def test_struct
a = S.new(1,2)
a.b = a
assert_equal("#<struct Struct::S a=1, b=#<struct Struct::S:...>>\n", PP.pp(a, ''))
assert_equal("#{a.inspect}\n", PP.pp(a, ''))
end
def test_object
a = Object.new
a.instance_eval {@a = a}
assert_equal(a.inspect + "\n", PP.pp(a, ''))
end
def test_anonymous
a = Class.new.new
assert_equal(a.inspect + "\n", PP.pp(a, ''))
end
def test_withinspect
a = []
a << HasInspect.new(a)
assert_equal("[<inspect:[...]>]\n", PP.pp(a, ''))
assert_equal("#{a.inspect}\n", PP.pp(a, ''))
end
def test_share_nil
begin
PP.sharing_detection = true
a = [nil, nil]
assert_equal("[nil, nil]\n", PP.pp(a, ''))
ensure
PP.sharing_detection = false
end
end
end
class PPSingleLineTest < Test::Unit::TestCase
def test_hash
assert_equal("{1=>1}", PP.singleline_pp({ 1 => 1}, '')) # [ruby-core:02699]
assert_equal("[1#{', 1'*99}]", PP.singleline_pp([1]*100, ''))
end
end
end