Module: MultiJson::OkJson

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

Defined Under Namespace

Classes: Error

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 249

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 431

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

#arrparse(ts) ⇒ Object

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 133

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.



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# File 'lib/multi_json/vendor/ok_json.rb', line 41

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

#eat(typ, ts) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 161

def eat(typ, ts)
  if ts[0][0] != typ
    raise Error, "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.) X itself must be an Array or a Hash. No other value can be encoded, and an error will be raised if x contains any other value, such as Nan, Infinity, Symbol, and Proc, or if a Hash key is not a String. Strings contained in x must be valid UTF-8.



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# File 'lib/multi_json/vendor/ok_json.rb', line 397

def encode(x)
  case x
  when Hash    then objenc(x)
  when Array   then arrenc(x)
  else
    raise Error, 'root value must be an Array or a Hash'
  end
end

#falsetok(s) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 223

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

#hexdec4(s) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 347

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

#hexenc4(t, u) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 487

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

#keyenc(k) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 436

def keyenc(k)
  case k
  when String then strenc(k)
  else
    raise Error, "Hash key is not a string: #{k.inspect}"
  end
end

#lex(s) ⇒ Object

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 171

def lex(s)
  ts = []
  while s.length > 0
    typ, lexeme, val = tok(s)
    if typ == nil
      raise Error, "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



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# File 'lib/multi_json/vendor/ok_json.rb', line 377

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 Error, "invalid hex code #{c}"
  end
end

#nulltok(s) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 221

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

#numenc(x) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 495

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

#numtok(s) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 226

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 426

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

#objparse(ts) ⇒ Object

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 90

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 values and any trailing tokens.



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# File 'lib/multi_json/vendor/ok_json.rb', line 120

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

#strenc(s) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 445

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 240

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

#subst(u1, u2) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 355

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)


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# File 'lib/multi_json/vendor/ok_json.rb', line 372

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.



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# File 'lib/multi_json/vendor/ok_json.rb', line 55

def textparse(ts)
  if ts.length < 0
    raise Error, 'empty'
  end

  typ, _, val = ts[0]
  case typ
  when '{' then objparse(ts)
  when '[' then arrparse(ts)
  else
    raise Error, "unexpected #{val.inspect}"
  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.



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# File 'lib/multi_json/vendor/ok_json.rb', line 200

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 222

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.



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# File 'lib/multi_json/vendor/ok_json.rb', line 506

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.



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# File 'lib/multi_json/vendor/ok_json.rb', line 323

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 an error if q contains control characters.



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# File 'lib/multi_json/vendor/ok_json.rb', line 261

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 Error, "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 Error, "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 Error, "invalid escape char #{q[r]} in \"#{q}\""
      end
    when c == ?", c < Spc
      raise Error, "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



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# File 'lib/multi_json/vendor/ok_json.rb', line 363

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

#valenc(x) ⇒ Object



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# File 'lib/multi_json/vendor/ok_json.rb', line 407

def valenc(x)
  case x
  when Hash    then objenc(x)
  when Array   then arrenc(x)
  when String  then strenc(x)
  when Numeric then numenc(x)
  when true    then "true"
  when false   then "false"
  when nil     then "null"
  else
    if x.respond_to?(:to_json)
      x.to_json
    else
      raise Error, "cannot encode #{x.class}: #{x.inspect}"
    end
  end
end

#valparse(ts) ⇒ Object

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



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# File 'lib/multi_json/vendor/ok_json.rb', line 72

def valparse(ts)
  if ts.length < 0
    raise Error, '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 Error, "unexpected #{val.inspect}"
  end
end