summaryrefslogtreecommitdiff
path: root/lib/pp.rb
blob: 7d1c502817d84b8e542da9bc77c7290a904bfdbc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
# frozen_string_literal: true

require 'prettyprint'

module Kernel
  # Returns a pretty printed object as a string.
  #
  # In order to use this method you must first require the PP module:
  #
  #   require 'pp'
  #
  # See the PP module for more information.
  def pretty_inspect
    PP.pp(self, ''.dup)
  end

  # prints arguments in pretty form.
  #
  # pp returns argument(s).
  def pp(*objs)
    objs.each {|obj|
      PP.pp(obj)
    }
    objs.size <= 1 ? objs.first : objs
  end
  module_function :pp
end

##
# A pretty-printer for Ruby objects.
#
# All examples assume you have loaded the PP class with:
#   require 'pp'
#
##
# == What PP Does
#
# Standard output by #p returns this:
#   #<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 returns this:
#   #<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>
#
##
# == Usage
#
#   pp(obj)             #=> obj
#   pp obj              #=> obj
#   pp(obj1, obj2, ...) #=> [obj1, obj2, ...]
#   pp()                #=> nil
#
# Output <tt>obj(s)</tt> to <tt>$></tt> in pretty printed format.
#
# It returns <tt>obj(s)</tt>.
#
##
# == Output Customization
#
# To define a customized pretty printing function for your classes,
# redefine method <code>#pretty_print(pp)</code> in the class.
#
# <code>#pretty_print</code> takes the +pp+ argument, which is an instance of the PP class.
# The method uses #text, #breakable, #nest, #group and #pp to print the
# object.
#
##
# == Pretty-Print JSON
#
# To pretty-print JSON refer to JSON#pretty_generate.
#
##
# == Author
# Tanaka Akira <akr@fsij.org>

class PP < PrettyPrint
  # Outputs +obj+ to +out+ in pretty printed format of
  # +width+ columns in width.
  #
  # If +out+ is omitted, <code>$></code> is assumed.
  # If +width+ is omitted, 79 is assumed.
  #
  # PP.pp returns +out+.
  def PP.pp(obj, out=$>, 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

    # Yields to a block
    # and preserves the previous set of objects being printed.
    def guard_inspect_key
      if Thread.current[:__recursive_key__] == nil
        Thread.current[:__recursive_key__] = {}.taint
      end

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

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

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

    # 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.
    def check_inspect_key(id)
      Thread.current[:__recursive_key__] &&
      Thread.current[:__recursive_key__][:inspect] &&
      Thread.current[:__recursive_key__][:inspect].include?(id)
    end

    # Adds the object_id +id+ to the set of objects being pretty printed, so
    # as to not repeat objects.
    def push_inspect_key(id)
      Thread.current[:__recursive_key__][:inspect][id] = true
    end

    # Removes an object from the set of objects being pretty printed.
    def pop_inspect_key(id)
      Thread.current[:__recursive_key__][:inspect].delete id
    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.object_id

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

      begin
        push_inspect_key(id)
        group {obj.pretty_print self}
      ensure
        pop_inspect_key(id) 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

    # A convenience method, like object_group, but also reformats the Object's
    # object_id.
    def object_address_group(obj, &block)
      str = Kernel.instance_method(:to_s).bind(obj).call
      str.chomp!('>')
      group(1, str, '>', &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 { q.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

    # A present standard failsafe for pretty printing any given Object
    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

    # A pretty print for a Hash
    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 # :nodoc:
    include PPMethods
  end

  module ObjectMixin # :nodoc:
    # 1. specific pretty_print
    # 2. specific inspect
    # 3. 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)
      method_method = Object.instance_method(:method).bind(self)
      begin
        inspect_method = method_method.call(:inspect)
      rescue NameError
      end
      if inspect_method && inspect_method.owner != Kernel
        q.text self.inspect
      elsif !inspect_method && self.respond_to?(:inspect)
        q.text self.inspect
      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 Object.instance_method(:method).bind(self).call(:pretty_print).owner == PP::ObjectMixin
        raise "pretty_print is not overridden for #{self.class}"
      end
      PP.singleline_pp(self, ''.dup)
    end
  end
end

class Array # :nodoc:
  def pretty_print(q) # :nodoc:
    q.group(1, '[', ']') {
      q.seplist(self) {|v|
        q.pp v
      }
    }
  end

  def pretty_print_cycle(q) # :nodoc:
    q.text(empty? ? '[]' : '[...]')
  end
end

class Hash # :nodoc:
  def pretty_print(q) # :nodoc:
    q.pp_hash self
  end

  def pretty_print_cycle(q) # :nodoc:
    q.text(empty? ? '{}' : '{...}')
  end
end

class << ENV # :nodoc:
  def pretty_print(q) # :nodoc:
    h = {}
    ENV.keys.sort.each {|k|
      h[k] = ENV[k]
    }
    q.pp_hash h
  end
end

class Struct # :nodoc:
  def pretty_print(q) # :nodoc:
    q.group(1, sprintf("#<struct %s", 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) # :nodoc:
    q.text sprintf("#<struct %s:...>", PP.mcall(self, Kernel, :class).name)
  end
end

class Range # :nodoc:
  def pretty_print(q) # :nodoc:
    q.pp self.begin
    q.breakable ''
    q.text(self.exclude_end? ? '...' : '..')
    q.breakable ''
    q.pp self.end
  end
end

class String # :nodoc:
  def pretty_print(q) # :nodoc:
    lines = self.lines
    if lines.size > 1
      q.group(0, '', '') do
        q.seplist(lines, lambda { q.text ' +'; q.breakable }) do |v|
          q.pp v
        end
      end
    else
      q.text inspect
    end
  end
end

class File < IO # :nodoc:
  class Stat # :nodoc:
    def pretty_print(q) # :nodoc:
      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)
          if self.rdev_major && self.rdev_minor
            q.breakable
            q.text sprintf('(%d, %d)', self.rdev_major, self.rdev_minor)
          end
        }
        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 # :nodoc:
  def pretty_print(q) # :nodoc:
    nc = []
    self.regexp.named_captures.each {|name, indexes|
      indexes.each {|i| nc[i] = name }
    }
    q.object_group(self) {
      q.breakable
      q.seplist(0...self.size, lambda { q.breakable }) {|i|
        if i == 0
          q.pp self[i]
        else
          if nc[i]
            q.text nc[i]
          else
            q.pp i
          end
          q.text ':'
          q.pp self[i]
        end
      }
    }
  end
end

class Object < BasicObject # :nodoc:
  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
  }
}