module Transcriptic::OkJson

Constants

Hex
Spc
Uchar1max
Uchar2max
Uchar3max
Ucharerr
Umask2
Umask3
Umask4
Umaskx
Umax
Unesc
Usurr1
Usurr2
Usurr3
Usurrself
Utag2
Utag3
Utag4
Utag5
Utagx

Public Instance Methods

abbrev(s) click to toggle source
# File lib/vendor/okjson.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) click to toggle source
# File lib/vendor/okjson.rb, line 388
def arrenc(a)
  '[' + a.map{|x| encode(x)}.join(',') + ']'
end
arrparse(ts) click to toggle source

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

# File lib/vendor/okjson.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) click to toggle source

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.

# File lib/vendor/okjson.rb, line 42
def decode(s)
  ts = lex(s)
  v, ts = textparse(ts)
  if ts.length > 0
    raise Transcriptic::OkJson::ParserError, 'trailing garbage'
  end
  v
end
eat(typ, ts) click to toggle source
# File lib/vendor/okjson.rb, line 161
def eat(typ, ts)
  if ts[0][0] != typ
    raise Transcriptic::OkJson::ParserError, "expected #{typ} (got #{ts[0].inspect})"
  end
  ts[1..-1]
end
encode(x) click to toggle source

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.

# File lib/vendor/okjson.rb, line 368
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) click to toggle source
# File lib/vendor/okjson.rb, line 223
def falsetok(s); s[0,5] == 'false' && [:val, 'false', false] end
hexdec4(s) click to toggle source
# File lib/vendor/okjson.rb, line 320
def hexdec4(s)
  if s.length != 4
    raise Transcriptic::OkJson::ParserError, 'short'
  end
  (nibble(s[0])<<12) | (nibble(s[1])<<8) | (nibble(s[2])<<4) | nibble(s[3])
end
hexenc4(t, u) click to toggle source
# File lib/vendor/okjson.rb, line 435
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) click to toggle source

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

# File lib/vendor/okjson.rb, line 171
def lex(s)
  ts = []
  while s.length > 0
    typ, lexeme, val = tok(s)
    if typ == nil
      raise Transcriptic::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) click to toggle source
# File lib/vendor/okjson.rb, line 350
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 Transcriptic::OkJson::ParserError, "invalid hex code #{c}"
  end
end
nulltok(s) click to toggle source
# File lib/vendor/okjson.rb, line 221
def nulltok(s);  s[0,4] == 'null'  && [:val, 'null',  nil]   end
numenc(x) click to toggle source
# File lib/vendor/okjson.rb, line 443
def numenc(x)
  if x.nan? || x.infinite?
    return 'null'
  end rescue nil
  "#{x}"
end
numtok(s) click to toggle source
# File lib/vendor/okjson.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) click to toggle source
# File lib/vendor/okjson.rb, line 383
def objenc(x)
  '{' + x.map{|k,v| encode(k) + ':' + encode(v)}.join(',') + '}'
end
objparse(ts) click to toggle source

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

# File lib/vendor/okjson.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) click to toggle source

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

# File lib/vendor/okjson.rb, line 120
def pairparse(ts)
  (typ, _, k), ts = ts[0], ts[1..-1]
  if typ != :str
    raise Transcriptic::OkJson::ParserError, "unexpected #{k.inspect}"
  end
  ts = eat(':', ts)
  v, ts = valparse(ts)
  [k, v, ts]
end
strenc(s) click to toggle source
# File lib/vendor/okjson.rb, line 393
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) click to toggle source
# File lib/vendor/okjson.rb, line 240
def strtok(s)
  m = /"([^"\\]|\\["\/\\bfnrt]|\\u[0-9a-fA-F]{4})*"/.match(s)
  if ! m
    raise Transcriptic::OkJson::ParserError, "invalid string literal at #{abbrev(s)}"
  end
  [:str, m[0], unquote(m[0])]
end
subst(u1, u2) click to toggle source
# File lib/vendor/okjson.rb, line 328
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) click to toggle source
# File lib/vendor/okjson.rb, line 345
def surrogate?(u)
  Usurr1 <= u && u < Usurr3
end
textparse(ts) click to toggle source

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.

# File lib/vendor/okjson.rb, line 56
def textparse(ts)
  if ts.length < 0
    raise Transcriptic::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) click to toggle source

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.

# File lib/vendor/okjson.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) click to toggle source
# File lib/vendor/okjson.rb, line 222
def truetok(s);  s[0,4] == 'true'  && [:val, 'true',  true]  end
uchardec(s, i) click to toggle source

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

# File lib/vendor/okjson.rb, line 454
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) click to toggle source

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

# File lib/vendor/okjson.rb, line 511
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) click to toggle source

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 Transcriptic::OkJson::ParserError, an error if q contains control characters.

# File lib/vendor/okjson.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 Transcriptic::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 Transcriptic::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 Transcriptic::OkJson::ParserError, "invalid escape char #{q[r]} in \"#{q}\""
      end
    when c == ?", c < Spc
      raise Transcriptic::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) click to toggle source
# File lib/vendor/okjson.rb, line 336
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) click to toggle source

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

# File lib/vendor/okjson.rb, line 72
def valparse(ts)
  if ts.length < 0
    raise Transcriptic::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 Transcriptic::OkJson::ParserError, "unexpected #{val.inspect}"
  end
end