summaryrefslogtreecommitdiff
path: root/lib/pp.rb
diff options
context:
space:
mode:
Diffstat (limited to 'lib/pp.rb')
-rw-r--r--lib/pp.rb549
1 files changed, 549 insertions, 0 deletions
diff --git a/lib/pp.rb b/lib/pp.rb
new file mode 100644
index 0000000000..7178c5c78a
--- /dev/null
+++ b/lib/pp.rb
@@ -0,0 +1,549 @@
+# $Id$
+
+=begin
+= Pretty-printer for Ruby objects.
+
+== Which seems better?
+
+non-pretty-printed output by (({p})) is:
+ #<PP:0x806486c @stack=[], @nest=[0], @buf=#<PP::Group:0x8064844 @tail=0, @singleline_length=9, @buf=[#<PP::Group:0x80647cc @tail=0, @singleline_length=9, @buf=[#<PP::Text:0x8064768 @text="[">, #<PP::Group:0x80646c8 @tail=1, @singleline_length=1, @buf=[#<PP::Text:0x8064664 @text="1">]>, #<PP::Text:0x80646b4 @text=",">, #<PP::Breakable:0x8064650 @indent=1, @sep=" ">, #<PP::Group:0x8064614 @tail=1, @singleline_length=1, @buf=[#<PP::Text:0x80645b0 @text="2">]>, #<PP::Text:0x8064600 @text=",">, #<PP::Breakable:0x806459c @indent=1, @sep=" ">, #<PP::Group:0x8064560 @tail=1, @singleline_length=1, @buf=[#<PP::Text:0x80644fc @text="3">]>, #<PP::Text:0x806472c @text="]">]>]>>
+
+pretty-printed output by (({pp})) is:
+ #<PP:0x403279c
+ @buf=
+ #<PP::Group:0x4032666
+ @buf=
+ [#<PP::Group:0x4032666
+ @buf=
+ [#<PP::Text:0x40326de @text="[">,
+ #<PP::Group:0x4032666
+ @buf=[#<PP::Text:0x40326de @text="1">],
+ @singleline_length=1,
+ @tail=1>,
+ #<PP::Text:0x40326de @text=",">,
+ #<PP::Breakable:0x40326b6 @indent=1, @sep=" ">,
+ #<PP::Group:0x4032666
+ @buf=[#<PP::Text:0x40326de @text="2">],
+ @singleline_length=1,
+ @tail=1>,
+ #<PP::Text:0x40326de @text=",">,
+ #<PP::Breakable:0x40326b6 @indent=1, @sep=" ">,
+ #<PP::Group:0x4032666
+ @buf=[#<PP::Text:0x40326de @text="3">],
+ @singleline_length=1,
+ @tail=1>,
+ #<PP::Text:0x40326de @text="]">],
+ @singleline_length=9,
+ @tail=0>],
+ @singleline_length=9,
+ @tail=0>,
+ @nest=[0],
+ @stack=[]>
+
+I like the latter. If you do too, this library is for you.
+
+== Usage
+
+: pp(obj)
+ output ((|obj|)) to (({$>})) in pretty printed format.
+
+== Customized output
+To define your customized pretty printing function for your class,
+redefine a method (({pretty_print(((|pp|)))})) in the class.
+It takes an argument ((|pp|)) which is an instance of the class ((<PP>)).
+The method should use PP#text, PP#breakable, PP#nest, PP#group and
+PP#pp to print the object.
+
+= PP
+== super class
+((<PrettyPrint>))
+
+== class methods
+--- PP.pp(obj[, width[, out]])
+ outputs ((|obj|)) to ((|out|)) in pretty printed format of
+ ((|width|)) columns in width.
+
+--- PP.sharing_detection
+ returns the sharing detection flag as boolean value.
+ It is false by default.
+
+--- PP.sharing_detection = value
+ sets the sharing detection flag.
+
+== methods
+--- pp(obj)
+ adds ((|obj|)) to the pretty printing buffer
+ using Object#pretty_print or Object#pretty_print_cycled.
+
+ Object#pretty_print_cycled is used when ((|obj|)) is already
+ printed, a.k.a the object reference chain has a cycle.
+
+= Object
+--- pretty_print(pp)
+ is a default pretty printing method for general objects.
+
+ If (({self})) has a customized (redefined) (({inspect})) method,
+ the result of (({self.inspect})) is used but it obviously has no
+ line break hints.
+
+ This module provides predefined pretty_print() methods for some of
+ the most commonly used built-in classes for convenience.
+
+--- pretty_print_cycled(pp)
+ is a default pretty printing method for general objects that are
+ detected as part of a cycle.
+=end
+
+require 'prettyprint'
+
+module Kernel
+ private
+ def pp(*objs)
+ objs.each {|obj|
+ PP.pp(obj)
+ }
+ end
+end
+
+class PP < PrettyPrint
+ def PP.pp(obj, width=79, out=$>)
+ pp = PP.new
+ pp.guard_inspect_key {pp.pp obj}
+ pp.format(out, width)
+ out << "\n"
+ end
+
+ @@sharing_detection = false
+ def PP.sharing_detection
+ return @@sharing_detection
+ end
+
+ def PP.sharing_detection=(val)
+ @@sharing_detection = val
+ end
+
+ def initialize
+ super
+ @sharing_detection = @@sharing_detection
+ end
+
+ 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
+
+ def pp(obj)
+ id = obj.__id__
+
+ if Thread.current[InspectKey].include? id
+ group {obj.pretty_print_cycled self}
+ return
+ end
+
+ begin
+ Thread.current[InspectKey] << id
+ group {obj.pretty_print self}
+ ensure
+ Thread.current[InspectKey].pop unless @sharing_detection
+ end
+ end
+
+ def pp_object(obj)
+ group {
+ text '#<'
+ nest(1) {
+ text obj.class.name
+ text ':'
+ text sprintf('0x%x', obj.__id__)
+ first = true
+ obj.instance_variables.sort.each {|v|
+ if first
+ first = false
+ else
+ text ','
+ end
+ breakable
+ group {
+ text v
+ text '='
+ nest(1) {
+ breakable ''
+ pp(obj.instance_eval v)
+ }
+ }
+ }
+ }
+ text '>'
+ }
+ end
+
+ def pp_hash(obj)
+ group {
+ text '{'
+ nest(1) {
+ first = true
+ obj.each {|k, v|
+ if first
+ first = false
+ else
+ text ","
+ breakable
+ end
+ group {
+ pp k
+ text '=>'
+ nest(1) {
+ group {
+ breakable ''
+ pp v
+ }
+ }
+ }
+ }
+ }
+ text '}'
+ }
+ end
+
+ module ObjectMixin
+ # 1. specific pretty_print
+ # 2. specific inspect
+ # 3. generic pretty_print
+
+ Key = :__pp_instead_of_inspect__
+
+ def pretty_print(pp)
+ # specific pretty_print is not defined, try specific inspect.
+ begin
+ old = Thread.current[Key]
+ result1 = sprintf('#<%s:0x%x pretty_printed>', self.class.name, self.__id__)
+ Thread.current[Key] = [pp, result1]
+ result2 = ObjectMixin.pp_call_inspect(self)
+ ensure
+ Thread.current[Key] = old
+ end
+
+ unless result1.equal? result2
+ pp.text result2
+ end
+ end
+
+ def ObjectMixin.pp_call_inspect(obj); obj.inspect; end
+ CallInspectFrame = "#{__FILE__}:#{__LINE__ - 1}:in `pp_call_inspect'"
+
+ def inspect
+ if CallInspectFrame == caller[0]
+ # specific inspect is also not defined, use generic pretty_print.
+ pp, result = Thread.current[Key]
+ pp.pp_object(self)
+ result
+ else
+ super
+ end
+ end
+
+ def pretty_print_cycled(pp)
+ pp.text sprintf("#<%s:0x%x", self.class.name, self.__id__)
+ pp.breakable
+ pp.text sprintf("...>")
+ end
+ end
+end
+
+[Numeric, FalseClass, TrueClass, Module].each {|c|
+ c.class_eval {
+ def pretty_print(pp)
+ pp.text self.to_s
+ end
+ }
+}
+
+class Array
+ def pretty_print(pp)
+ pp.text "["
+ pp.nest(1) {
+ first = true
+ self.each {|v|
+ if first
+ first = false
+ else
+ pp.text ","
+ pp.breakable
+ end
+ pp.pp v
+ }
+ }
+ pp.text "]"
+ end
+
+ def pretty_print_cycled(pp)
+ pp.text(empty? ? '[]' : '[...]')
+ end
+end
+
+class Hash
+ def pretty_print(pp)
+ pp.pp_hash self
+ end
+
+ def pretty_print_cycled(pp)
+ pp.text(empty? ? '{}' : '{...}')
+ end
+end
+
+class << ENV
+ def pretty_print(pp)
+ pp.pp_hash self
+ end
+end
+
+class Struct
+ def pretty_print(pp)
+ pp.text sprintf("#<%s", self.class.name)
+ pp.nest(1) {
+ first = true
+ self.members.each {|member|
+ if first
+ first = false
+ else
+ pp.text ","
+ end
+ pp.breakable
+ pp.group {
+ pp.text member.to_s
+ pp.text '='
+ pp.nest(1) {
+ pp.breakable ''
+ pp.pp self[member]
+ }
+ }
+ }
+ }
+ pp.text ">"
+ end
+
+ def pretty_print_cycled(pp)
+ pp.text sprintf("#<%s:...>", self.class.name)
+ end
+end
+
+class Range
+ def pretty_print(pp)
+ pp.pp self.begin
+ pp.breakable ''
+ pp.text(self.exclude_end? ? '...' : '..')
+ pp.breakable ''
+ pp.pp self.end
+ end
+end
+
+class File
+ class Stat
+ def pretty_print(pp)
+ require 'etc.so'
+ pp.nest(1) {
+ pp.text "#<"
+ pp.text self.class.name
+ pp.breakable; pp.text "dev="; pp.pp self.dev; pp.text ','
+ pp.breakable; pp.text "ino="; pp.pp self.ino; pp.text ','
+ pp.breakable
+ pp.group {
+ m = self.mode
+ pp.text "mode="; pp.pp m
+ pp.breakable
+ pp.text sprintf("(0%o %s %c%c%c%c%c%c%c%c%c)",
+ m, 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)))
+ pp.text ','
+ }
+ pp.breakable; pp.text "nlink="; pp.pp self.nlink; pp.text ','
+ pp.breakable
+ pp.group {
+ pp.text "uid="; pp.pp self.uid
+ begin
+ name = Etc.getpwuid(self.uid).name
+ pp.breakable; pp.text "(#{name})"
+ rescue ArgumentError
+ end
+ pp.text ','
+ }
+ pp.breakable
+ pp.group {
+ pp.text "gid="; pp.pp self.gid
+ begin
+ name = Etc.getgrgid(self.gid).name
+ pp.breakable; pp.text "(#{name})"
+ rescue ArgumentError
+ end
+ pp.text ','
+ }
+ pp.breakable; pp.text "rdev="; pp.pp self.rdev; pp.text ','
+ pp.breakable; pp.text "size="; pp.pp self.size; pp.text ','
+ pp.breakable; pp.text "blksize="; pp.pp self.blksize; pp.text ','
+ pp.breakable; pp.text "blocks="; pp.pp self.blocks; pp.text ','
+ pp.breakable
+ pp.group {
+ t = self.atime
+ pp.text "atime="; pp.pp t
+ pp.breakable; pp.text "(#{t.tv_sec})"
+ pp.text ','
+ }
+ pp.breakable
+ pp.group {
+ t = self.mtime
+ pp.text "mtime="; pp.pp t
+ pp.breakable; pp.text "(#{t.tv_sec})"
+ pp.text ','
+ }
+ pp.breakable
+ pp.group {
+ t = self.ctime
+ pp.text "ctime="; pp.pp t
+ pp.breakable; pp.text "(#{t.tv_sec})"
+ }
+ pp.text ">"
+ }
+ end
+ end
+end
+
+class Object
+ include PP::ObjectMixin
+end
+
+[Numeric, Symbol, FalseClass, TrueClass, NilClass, Module].each {|c|
+ c.class_eval {
+ alias :pretty_print_cycled :pretty_print
+ }
+}
+
+if __FILE__ == $0
+ require 'runit/testcase'
+ require 'runit/cui/testrunner'
+
+ class PPTest < RUNIT::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
+ 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(pp)
+ pp.text "<pretty_print:"
+ pp.pp @a
+ pp.text ">"
+ end
+ end
+
+ class HasBoth
+ def initialize(a)
+ @a = a
+ end
+
+ def inspect
+ return "<inspect:#{@a.inspect}>"
+ end
+
+ def pretty_print(pp)
+ pp.text "<pretty_print:"
+ pp.pp @a
+ pp.text ">"
+ end
+ end
+
+ class PPInspectTest < RUNIT::TestCase
+ def test_hasinspect
+ a = HasInspect.new(1)
+ assert_equal("<inspect:1>\n", PP.pp(a, 79, ''))
+ end
+
+ def test_hasprettyprint
+ a = HasPrettyPrint.new(1)
+ assert_equal("<pretty_print:1>\n", PP.pp(a, 79, ''))
+ end
+
+ def test_hasboth
+ a = HasBoth.new(1)
+ assert_equal("<pretty_print:1>\n", PP.pp(a, 79, ''))
+ end
+ end
+
+ class PPCycleTest < RUNIT::TestCase
+ def test_array
+ a = []
+ a << a
+ assert_equal("[[...]]\n", PP.pp(a, 79, ''))
+ end
+
+ def test_hash
+ a = {}
+ a[0] = a
+ assert_equal("{0=>{...}}\n", PP.pp(a, 79, ''))
+ end
+
+ S = Struct.new("S", :a, :b)
+ def test_struct
+ a = S.new(1,2)
+ a.b = a
+ assert_equal("#<Struct::S a=1, b=#<Struct::S:...>>\n", PP.pp(a, 79, ''))
+ end
+
+ def test_object
+ a = Object.new
+ a.instance_eval {@a = a}
+ hex = '0x' + ('%x'%a.id)
+ assert_equal("#<Object:#{hex} @a=#<Object:#{hex} ...>>\n", PP.pp(a, 79, ''))
+ end
+
+ def test_withinspect
+ a = []
+ a << HasInspect.new(a)
+ assert_equal("[<inspect:[...]>]\n", PP.pp(a, 79, ''))
+ end
+ end
+
+ RUNIT::CUI::TestRunner.run(PPTest.suite)
+ RUNIT::CUI::TestRunner.run(PPInspectTest.suite)
+ RUNIT::CUI::TestRunner.run(PPCycleTest.suite)
+end
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-01 21:34:20 +0000