Module: OkJson

Extended by:
OkJson
Included in:
OkJson
Defined in:
lib/vendor/okjson.rb

Overview

Some parts adapted from golang.org/src/pkg/json/decode.go and golang.org/src/pkg/utf8/utf8.go

Defined Under Namespace

Classes: ParserError

Constant Summary collapse

Utagx =

1000 0000

0x80
Utag2 =

1100 0000

0xc0
Utag3 =

1110 0000

0xe0
Utag4 =

1111 0000

0xf0
Utag5 =

1111 1000

0xF8
Umaskx =

0011 1111

0x3f
Umask2 =

0001 1111

0x1f
Umask3 =

0000 1111

0x0f
Umask4 =

0000 0111

0x07
Uchar1max = 
(1<<7) - 1
Uchar2max = 
(1<<11) - 1
Uchar3max = 
(1<<16) - 1
Ucharerr =

unicode “replacement char”

0xFFFD
Usurrself = 
0x10000
Usurr1 = 
0xd800
Usurr2 = 
0xdc00
Usurr3 = 
0xe000
Umax = 
0x10ffff
Spc = 

      
        
Unesc =
          
        

        
{?b=>?\b, ?f=>?\f, ?n=>?\n, ?r=>?\r, ?t=>?\t}

      
        
Hex =
          
        

        
'0123456789abcdef'

      
    

  







  
    

      Instance Method Summary
      collapse
    


    
  



  

    
Instance Method Details


    
      

  

  
    #abbrev(s)  ⇒ Object 
  

  

  




  

    
      


248
249
250
251
252
253
254

    		
    
      
# File 'lib/vendor/okjson.rb', line 248

def abbrev(s)
  t = s[0,10]
  p = t['`']
  t = t[0,p] if p
  t = t + '...' if t.length < s.length
  '`' + t + '`'
end

    		
  





    
      

  

  
    #arrenc(a)  ⇒ Object 
  

  

  




  

    
      


387
388
389

    		
    
      
# File 'lib/vendor/okjson.rb', line 387

def arrenc(a)
  '[' + a.map{|x| encode(x)}.join(',') + ']'
end

    		
  





    
      

  

  
    #arrparse(ts)  ⇒ Object 
  

  

  




  

    

Parses an “array” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



  





  



  

    
      


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

    		
    
      
# File 'lib/vendor/okjson.rb', line 132

def arrparse(ts)
  ts = eat('[', ts)
  arr = []

  if ts[0][0] == ']'
    return arr, ts[1..-1]
  end

  v, ts = valparse(ts)
  arr << v

  if ts[0][0] == ']'
    return arr, ts[1..-1]
  end

  loop do
    ts = eat(',', ts)

    v, ts = valparse(ts)
    arr << v

    if ts[0][0] == ']'
      return arr, ts[1..-1]
    end
  end
end

    		
  





    
      

  

  
    #decode(s)  ⇒ Object 
  

  

  




  

    

Decodes a json document in string s and returns the corresponding ruby value. String s must be valid UTF-8. If you have a string in some other encoding, convert it first.



String values in the resulting structure will be UTF-8.



  





  



  

    
      


41
42
43
44
45
46
47
48

    		
    
      
# File 'lib/vendor/okjson.rb', line 41

def decode(s)
  ts = lex(s)
  v, ts = textparse(ts)
  if ts.length > 0
    raise OkJson::ParserError, 'trailing garbage'
  end
  v
end

    		
  





    
      

  

  
    #eat(typ, ts)  ⇒ Object 
  

  

  




  

    
      


160
161
162
163
164
165

    		
    
      
# File 'lib/vendor/okjson.rb', line 160

def eat(typ, ts)
  if ts[0][0] != typ
    raise OkJson::ParserError, "expected #{typ} (got #{ts[0].inspect})"
  end
  ts[1..-1]
end

    		
  





    
      

  

  
    #encode(x)  ⇒ Object 
  

  

  




  

    

Encodes x into a json text. It may contain only Array, Hash, String, Numeric, true, false, nil. (Note, this list excludes Symbol.) Strings contained in x must be valid UTF-8. Values that cannot be represented, such as Nan, Infinity, Symbol, and Proc, are encoded as null, in accordance with ECMA-262, 5th ed.



  





  



  

    
      


367
368
369
370
371
372
373
374
375
376
377
378
379

    		
    
      
# File 'lib/vendor/okjson.rb', line 367

def encode(x)
  case x
  when Hash    then objenc(x)
  when Array   then arrenc(x)
  when String  then strenc(x)
  when Numeric then numenc(x)
  when Symbol  then strenc(x.to_s)
  when true    then "true"
  when false   then "false"
  when nil     then "null"
  else              "null"
  end
end

    		
  





    
      

  

  
    #falsetok(s)  ⇒ Object 
  

  

  




  

    
      


222

    		
    
      
# File 'lib/vendor/okjson.rb', line 222

def falsetok(s); s[0,5] == 'false' && [:val, 'false', false] end

    		
  





    
      

  

  
    #hexdec4(s)  ⇒ Object 
  

  

  




  

    
      


319
320
321
322
323
324

    		
    
      
# File 'lib/vendor/okjson.rb', line 319

def hexdec4(s)
  if s.length != 4
    raise OkJson::ParserError, 'short'
  end
  (nibble(s[0])<<12) | (nibble(s[1])<<8) | (nibble(s[2])<<4) | nibble(s[3])
end

    		
  





    
      

  

  
    #hexenc4(t, u)  ⇒ Object 
  

  

  




  

    
      


434
435
436
437
438
439

    		
    
      
# File 'lib/vendor/okjson.rb', line 434

def hexenc4(t, u)
  t.putc(Hex[(u>>12)&0xf])
  t.putc(Hex[(u>>8)&0xf])
  t.putc(Hex[(u>>4)&0xf])
  t.putc(Hex[u&0xf])
end

    		
  





    
      

  

  
    #lex(s)  ⇒ Object 
  

  

  




  

    

Sans s and returns a list of json tokens, excluding white space (as defined in RFC 4627).



  





  



  

    
      


170
171
172
173
174
175
176
177
178
179
180
181
182
183

    		
    
      
# File 'lib/vendor/okjson.rb', line 170

def lex(s)
  ts = []
  while s.length > 0
    typ, lexeme, val = tok(s)
    if typ == nil
      raise OkJson::ParserError, "invalid character at #{s[0,10].inspect}"
    end
    if typ != :space
      ts << [typ, lexeme, val]
    end
    s = s[lexeme.length..-1]
  end
  ts
end

    		
  





    
      

  

  
    #nibble(c)  ⇒ Object 
  

  

  




  

    
      


349
350
351
352
353
354
355
356
357

    		
    
      
# File 'lib/vendor/okjson.rb', line 349

def nibble(c)
  case true
  when ?0 <= c && c <= ?9 then c.ord - ?0.ord
  when ?a <= c && c <= ?z then c.ord - ?a.ord + 10
  when ?A <= c && c <= ?Z then c.ord - ?A.ord + 10
  else
    raise OkJson::ParserError, "invalid hex code #{c}"
  end
end

    		
  





    
      

  

  
    #nulltok(s)  ⇒ Object 
  

  

  




  

    
      


220

    		
    
      
# File 'lib/vendor/okjson.rb', line 220

def nulltok(s);  s[0,4] == 'null'  && [:val, 'null',  nil]   end

    		
  





    
      

  

  
    #numenc(x)  ⇒ Object 
  

  

  




  

    
      


442
443
444
445
446
447

    		
    
      
# File 'lib/vendor/okjson.rb', line 442

def numenc(x)
  if x.nan? || x.infinite?
    return 'null'
  end rescue nil
  "#{x}"
end

    		
  





    
      

  

  
    #numtok(s)  ⇒ Object 
  

  

  




  

    
      


225
226
227
228
229
230
231
232
233
234
235
236

    		
    
      
# File 'lib/vendor/okjson.rb', line 225

def numtok(s)
  m = /-?([1-9][0-9]+|[0-9])([.][0-9]+)?([eE][+-]?[0-9]+)?/.match(s)
  if m && m.begin(0) == 0
    if m[3] && !m[2]
      [:val, m[0], Integer(m[1])*(10**Integer(m[3][1..-1]))]
    elsif m[2]
      [:val, m[0], Float(m[0])]
    else
      [:val, m[0], Integer(m[0])]
    end
  end
end

    		
  





    
      

  

  
    #objenc(x)  ⇒ Object 
  

  

  




  

    
      


382
383
384

    		
    
      
# File 'lib/vendor/okjson.rb', line 382

def objenc(x)
  '{' + x.map{|k,v| encode(k) + ':' + encode(v)}.join(',') + '}'
end

    		
  





    
      

  

  
    #objparse(ts)  ⇒ Object 
  

  

  




  

    

Parses an “object” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



  





  



  

    
      


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

    		
    
      
# File 'lib/vendor/okjson.rb', line 89

def objparse(ts)
  ts = eat('{', ts)
  obj = {}

  if ts[0][0] == '}'
    return obj, ts[1..-1]
  end

  k, v, ts = pairparse(ts)
  obj[k] = v

  if ts[0][0] == '}'
    return obj, ts[1..-1]
  end

  loop do
    ts = eat(',', ts)

    k, v, ts = pairparse(ts)
    obj[k] = v

    if ts[0][0] == '}'
      return obj, ts[1..-1]
    end
  end
end

    		
  





    
      

  

  
    #pairparse(ts)  ⇒ Object 
  

  

  




  

    

Parses a “member” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



  





  



  

    
      


119
120
121
122
123
124
125
126
127

    		
    
      
# File 'lib/vendor/okjson.rb', line 119

def pairparse(ts)
  (typ, _, k), ts = ts[0], ts[1..-1]
  if typ != :str
    raise OkJson::ParserError, "unexpected #{k.inspect}"
  end
  ts = eat(':', ts)
  v, ts = valparse(ts)
  [k, v, ts]
end

    		
  





    
      

  

  
    #strenc(s)  ⇒ Object 
  

  

  




  

    
      


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

    		
    
      
# File 'lib/vendor/okjson.rb', line 392

def strenc(s)
  t = StringIO.new
  t.putc(?")
  r = 0
  while r < s.length
    case s[r]
    when ?"  then t.print('\\"')
    when ?\\ then t.print('\\\\')
    when ?\b then t.print('\\b')
    when ?\f then t.print('\\f')
    when ?\n then t.print('\\n')
    when ?\r then t.print('\\r')
    when ?\t then t.print('\\t')
    else
      c = s[r]
      case true
      when Spc <= c && c <= ?~
        t.putc(c)
      when true
        u, size = uchardec(s, r)
        r += size - 1 # we add one more at the bottom of the loop
        if u < 0x10000
          t.print('\\u')
          hexenc4(t, u)
        else
          u1, u2 = unsubst(u)
          t.print('\\u')
          hexenc4(t, u1)
          t.print('\\u')
          hexenc4(t, u2)
        end
      else
        # invalid byte; skip it
      end
    end
    r += 1
  end
  t.putc(?")
  t.string
end

    		
  





    
      

  

  
    #strtok(s)  ⇒ Object 
  

  

  




  

    
      


239
240
241
242
243
244
245

    		
    
      
# File 'lib/vendor/okjson.rb', line 239

def strtok(s)
  m = /"([^"\\]|\\["\/\\bfnrt]|\\u[0-9a-fA-F]{4})*"/.match(s)
  if ! m
    raise OkJson::ParserError, "invalid string literal at #{abbrev(s)}"
  end
  [:str, m[0], unquote(m[0])]
end

    		
  





    
      

  

  
    #subst(u1, u2)  ⇒ Object 
  

  

  




  

    
      


327
328
329
330
331
332

    		
    
      
# File 'lib/vendor/okjson.rb', line 327

def subst(u1, u2)
  if Usurr1 <= u1 && u1 < Usurr2 && Usurr2 <= u2 && u2 < Usurr3
    return ((u1-Usurr1)<<10) | (u2-Usurr2) + Usurrself
  end
  return Ucharerr
end

    		
  





    
      

  

  
    #surrogate?(u)  ⇒ Boolean 
  

  

  




  

    

  





  

Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
    
    • 
  





  

    
      


344
345
346

    		
    
      
# File 'lib/vendor/okjson.rb', line 344

def surrogate?(u)
  Usurr1 <= u && u < Usurr3
end

    		
  





    
      

  

  
    #textparse(ts)  ⇒ Object 
  

  

  




  

    

Parses a “json text” in the sense of RFC 4627. Returns the parsed value and any trailing tokens. Note: this is almost the same as valparse, except that it does not accept atomic values.



  





  



  

    
      


55
56
57
58
59
60
61
62
63
64
65
66

    		
    
      
# File 'lib/vendor/okjson.rb', line 55

def textparse(ts)
  if ts.length < 0
    raise OkJson::ParserError, 'empty'
  end

  typ, _, val = ts[0]
  case typ
  when '{' then objparse(ts)
  when '[' then arrparse(ts)
  else valparse(ts)
  end
end

    		
  





    
      

  

  
    #tok(s)  ⇒ Object 
  

  

  




  

    

Scans the first token in s and returns a 3-element list, or nil if no such token exists.



The first list element is one of ‘‘’, ‘:’, ‘,’, ‘[’, ‘]’, :val, :str, and :space.



The second element is the lexeme.



The third element is the value of the token for :val and :str, otherwise it is the lexeme.



  





  



  

    
      


199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217

    		
    
      
# File 'lib/vendor/okjson.rb', line 199

def tok(s)
  case s[0]
  when ?{  then ['{', s[0,1], s[0,1]]
  when ?}  then ['}', s[0,1], s[0,1]]
  when ?:  then [':', s[0,1], s[0,1]]
  when ?,  then [',', s[0,1], s[0,1]]
  when ?[  then ['[', s[0,1], s[0,1]]
  when ?]  then [']', s[0,1], s[0,1]]
  when ?n  then nulltok(s)
  when ?t  then truetok(s)
  when ?f  then falsetok(s)
  when ?"  then strtok(s)
  when Spc then [:space, s[0,1], s[0,1]]
  when ?\t then [:space, s[0,1], s[0,1]]
  when ?\n then [:space, s[0,1], s[0,1]]
  when ?\r then [:space, s[0,1], s[0,1]]
  else          numtok(s)
  end
end

    		
  





    
      

  

  
    #truetok(s)  ⇒ Object 
  

  

  




  

    
      


221

    		
    
      
# File 'lib/vendor/okjson.rb', line 221

def truetok(s);  s[0,4] == 'true'  && [:val, 'true',  true]  end

    		
  





    
      

  

  
    #uchardec(s, i)  ⇒ Object 
  

  

  




  

    

Decodes unicode character u from UTF-8 bytes in string s at position i. Returns u and the number of bytes read.



  





  



  

    
      


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

    		
    
      
# File 'lib/vendor/okjson.rb', line 453

def uchardec(s, i)
  n = s.length - i
  return [Ucharerr, 1] if n < 1

  c0 = s[i].ord

  # 1-byte, 7-bit sequence?
  if c0 < Utagx
    return [c0, 1]
  end

  # unexpected continuation byte?
  return [Ucharerr, 1] if c0 < Utag2

  # need continuation byte
  return [Ucharerr, 1] if n < 2
  c1 = s[i+1].ord
  return [Ucharerr, 1] if c1 < Utagx || Utag2 <= c1

  # 2-byte, 11-bit sequence?
  if c0 < Utag3
    u = (c0&Umask2)<<6 | (c1&Umaskx)
    return [Ucharerr, 1] if u <= Uchar1max
    return [u, 2]
  end

  # need second continuation byte
  return [Ucharerr, 1] if n < 3
  c2 = s[i+2].ord
  return [Ucharerr, 1] if c2 < Utagx || Utag2 <= c2

  # 3-byte, 16-bit sequence?
  if c0 < Utag4
    u = (c0&Umask3)<<12 | (c1&Umaskx)<<6 | (c2&Umaskx)
    return [Ucharerr, 1] if u <= Uchar2max
    return [u, 3]
  end

  # need third continuation byte
  return [Ucharerr, 1] if n < 4
  c3 = s[i+3].ord
  return [Ucharerr, 1] if c3 < Utagx || Utag2 <= c3

  # 4-byte, 21-bit sequence?
  if c0 < Utag5
    u = (c0&Umask4)<<18 | (c1&Umaskx)<<12 | (c2&Umaskx)<<6 | (c3&Umaskx)
    return [Ucharerr, 1] if u <= Uchar3max
    return [u, 4]
  end

  return [Ucharerr, 1]
end

    		
  





    
      

  

  
    #ucharenc(a, i, u)  ⇒ Object 
  

  

  




  

    

Encodes unicode character u as UTF-8 bytes in string a at position i. Returns the number of bytes written.



  





  



  

    
      


510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531

    		
    
      
# File 'lib/vendor/okjson.rb', line 510

def ucharenc(a, i, u)
  case true
  when u <= Uchar1max
    a[i] = (u & 0xff).chr
    1
  when u <= Uchar2max
    a[i+0] = (Utag2 | ((u>>6)&0xff)).chr
    a[i+1] = (Utagx | (u&Umaskx)).chr
    2
  when u <= Uchar3max
    a[i+0] = (Utag3 | ((u>>12)&0xff)).chr
    a[i+1] = (Utagx | ((u>>6)&Umaskx)).chr
    a[i+2] = (Utagx | (u&Umaskx)).chr
    3
  else
    a[i+0] = (Utag4 | ((u>>18)&0xff)).chr
    a[i+1] = (Utagx | ((u>>12)&Umaskx)).chr
    a[i+2] = (Utagx | ((u>>6)&Umaskx)).chr
    a[i+3] = (Utagx | (u&Umaskx)).chr
    4
  end
end

    		
  





    
      

  

  
    #unquote(q)  ⇒ Object 
  

  

  




  

    

Converts a quoted json string literal q into a UTF-8-encoded string. The rules are different than for Ruby, so we cannot use eval. Unquote will raise OkJson::ParserError, an error if q contains control characters.



  





  



  

    
      


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

    		
    
      
# File 'lib/vendor/okjson.rb', line 260

def unquote(q)
  q = q[1...-1]
  a = q.dup # allocate a big enough string
  r, w = 0, 0
  while r < q.length
    c = q[r]
    case true
    when c == ?\\
      r += 1
      if r >= q.length
        raise OkJson::ParserError, "string literal ends with a \"\\\": \"#{q}\""
      end

      case q[r]
      when ?",?\\,?/,?'
        a[w] = q[r]
        r += 1
        w += 1
      when ?b,?f,?n,?r,?t
        a[w] = Unesc[q[r]]
        r += 1
        w += 1
      when ?u
        r += 1
        uchar = begin
          hexdec4(q[r,4])
        rescue RuntimeError => e
          raise OkJson::ParserError, "invalid escape sequence \\u#{q[r,4]}: #{e}"
        end
        r += 4
        if surrogate? uchar
          if q.length >= r+6
            uchar1 = hexdec4(q[r+2,4])
            uchar = subst(uchar, uchar1)
            if uchar != Ucharerr
              # A valid pair; consume.
              r += 6
            end
          end
        end
        w += ucharenc(a, w, uchar)
      else
        raise OkJson::ParserError, "invalid escape char #{q[r]} in \"#{q}\""
      end
    when c == ?", c < Spc
      raise OkJson::ParserError, "invalid character in string literal \"#{q}\""
    else
      # Copy anything else byte-for-byte.
      # Valid UTF-8 will remain valid UTF-8.
      # Invalid UTF-8 will remain invalid UTF-8.
      a[w] = c
      r += 1
      w += 1
    end
  end
  a[0,w]
end

    		
  





    
      

  

  
    #unsubst(u)  ⇒ Object 
  

  

  




  

    
      


335
336
337
338
339
340
341

    		
    
      
# File 'lib/vendor/okjson.rb', line 335

def unsubst(u)
  if u < Usurrself || u > Umax || surrogate?(u)
    return Ucharerr, Ucharerr
  end
  u -= Usurrself
  [Usurr1 + ((u>>10)&0x3ff), Usurr2 + (u&0x3ff)]
end

    		
  





    
      

  

  
    #valparse(ts)  ⇒ Object 
  

  

  




  

    

Parses a “value” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



  





  



  

    
      


71
72
73
74
75
76
77
78
79
80
81
82
83
84

    		
    
      
# File 'lib/vendor/okjson.rb', line 71

def valparse(ts)
  if ts.length < 0
    raise OkJson::ParserError, 'empty'
  end

  typ, _, val = ts[0]
  case typ
  when '{' then objparse(ts)
  when '[' then arrparse(ts)
  when :val,:str then [val, ts[1..-1]]
  else
    raise OkJson::ParserError, "unexpected #{val.inspect}"
  end
end