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Edit File: okjson.rb
# encoding: UTF-8 # # Copyright 2011, 2012 Keith Rarick # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. # See https://github.com/kr/okjson for updates. require 'stringio' module MultiJson # Some parts adapted from # https://golang.org/src/encoding/json/decode.go and # https://golang.org/src/unicode/utf8/utf8.go module OkJson Upstream = '45' extend self # 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. def decode(s) ts = lex(s) v, ts = textparse(ts) if ts.length > 0 raise Error, 'trailing garbage' end v end # 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. 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 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 private # 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. 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 # Parses a "value" in the sense of RFC 4627. # Returns the parsed value and any trailing tokens. 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 # Parses an "object" in the sense of RFC 4627. # Returns the parsed value and any trailing tokens. 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 # Parses a "member" in the sense of RFC 4627. # Returns the parsed values and any trailing tokens. 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 # Parses an "array" in the sense of RFC 4627. # Returns the parsed value and any trailing tokens. 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 def eat(typ, ts) if ts[0][0] != typ raise Error, "expected #{typ} (got #{ts[0].inspect})" end ts[1..-1] end # Scans s and returns a list of json tokens, # excluding white space (as defined in RFC 4627). 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 # Scans the first token in s and # returns a 3-element list, or nil # if s does not begin with a valid token. # # 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. 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, ?\t, ?\n, ?\r then [:space, s[0,1], s[0,1]] else numtok(s) end end def nulltok(s); s[0,4] == 'null' ? [:val, 'null', nil] : [] end def truetok(s); s[0,4] == 'true' ? [:val, 'true', true] : [] end def falsetok(s); s[0,5] == 'false' ? [:val, 'false', false] : [] end 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[2] && !m[3] [:val, m[0], Integer(m[0])] elsif m[2] [:val, m[0], Float(m[0])] else [:val, m[0], Integer(m[1])*(10**m[3][1..-1].to_i(10))] end else [] end end 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 def abbrev(s) t = s[0,10] p = t['`'] t = t[0,p] if p t = t + '...' if t.length < s.length '`' + t + '`' end # 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. def unquote(q) q = q[1...-1] a = q.dup # allocate a big enough string # In ruby >= 1.9, a[w] is a codepoint, not a byte. if rubydoesenc? a.force_encoding('UTF-8') end r, w = 0, 0 while r < q.length c = q[r] if 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 if rubydoesenc? a[w] = '' << uchar w += 1 else w += ucharenc(a, w, uchar) end else raise Error, "invalid escape char #{q[r]} in \"#{q}\"" end elsif 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. # In ruby >= 1.9, c is a codepoint, not a byte, # in which case this is still what we want. a[w] = c r += 1 w += 1 end end a[0,w] end # Encodes unicode character u as UTF-8 # bytes in string a at position i. # Returns the number of bytes written. def ucharenc(a, i, u) if u <= Uchar1max a[i] = (u & 0xff).chr 1 elsif u <= Uchar2max a[i+0] = (Utag2 | ((u>>6)&0xff)).chr a[i+1] = (Utagx | (u&Umaskx)).chr 2 elsif 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 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 def subst(u1, u2) if Usurr1 <= u1 && u1 < Usurr2 && Usurr2 <= u2 && u2 < Usurr3 return ((u1-Usurr1)<<10) | (u2-Usurr2) + Usurrself end return Ucharerr end def surrogate?(u) Usurr1 <= u && u < Usurr3 end def nibble(c) if ?0 <= c && c <= ?9 then c.ord - ?0.ord elsif ?a <= c && c <= ?z then c.ord - ?a.ord + 10 elsif ?A <= c && c <= ?Z then c.ord - ?A.ord + 10 else raise Error, "invalid hex code #{c}" end end def objenc(x) '{' + x.map{|k,v| keyenc(k) + ':' + valenc(v)}.join(',') + '}' end def arrenc(a) '[' + a.map{|x| valenc(x)}.join(',') + ']' end def keyenc(k) case k when String then strenc(k) else raise Error, "Hash key is not a string: #{k.inspect}" end end 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] # In ruby >= 1.9, s[r] is a codepoint, not a byte. if rubydoesenc? begin # c.ord will raise an error if c is invalid UTF-8 if c.ord < Spc.ord c = "\\u%04x" % [c.ord] end t.write(c) rescue t.write(Ustrerr) end elsif c < Spc t.write("\\u%04x" % c) elsif Spc <= c && c <= ?~ t.putc(c) else n = ucharcopy(t, s, r) # ensure valid UTF-8 output r += n - 1 # r is incremented below end end r += 1 end t.putc(?") t.string end def numenc(x) if ((x.nan? || x.infinite?) rescue false) raise Error, "Numeric cannot be represented: #{x}" end "#{x}" end # Copies the valid UTF-8 bytes of a single character # from string s at position i to I/O object t, and # returns the number of bytes copied. # If no valid UTF-8 char exists at position i, # ucharcopy writes Ustrerr and returns 1. def ucharcopy(t, s, i) n = s.length - i raise Utf8Error if n < 1 c0 = s[i].ord # 1-byte, 7-bit sequence? if c0 < Utagx t.putc(c0) return 1 end raise Utf8Error if c0 < Utag2 # unexpected continuation byte? raise Utf8Error if n < 2 # need continuation byte c1 = s[i+1].ord raise Utf8Error if c1 < Utagx || Utag2 <= c1 # 2-byte, 11-bit sequence? if c0 < Utag3 raise Utf8Error if ((c0&Umask2)<<6 | (c1&Umaskx)) <= Uchar1max t.putc(c0) t.putc(c1) return 2 end # need second continuation byte raise Utf8Error if n < 3 c2 = s[i+2].ord raise Utf8Error if c2 < Utagx || Utag2 <= c2 # 3-byte, 16-bit sequence? if c0 < Utag4 u = (c0&Umask3)<<12 | (c1&Umaskx)<<6 | (c2&Umaskx) raise Utf8Error if u <= Uchar2max t.putc(c0) t.putc(c1) t.putc(c2) return 3 end # need third continuation byte raise Utf8Error if n < 4 c3 = s[i+3].ord raise Utf8Error 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) raise Utf8Error if u <= Uchar3max t.putc(c0) t.putc(c1) t.putc(c2) t.putc(c3) return 4 end raise Utf8Error rescue Utf8Error t.write(Ustrerr) return 1 end def rubydoesenc? ::String.method_defined?(:force_encoding) end class Utf8Error < ::StandardError end class Error < ::StandardError end Utagx = 0b1000_0000 Utag2 = 0b1100_0000 Utag3 = 0b1110_0000 Utag4 = 0b1111_0000 Utag5 = 0b1111_1000 Umaskx = 0b0011_1111 Umask2 = 0b0001_1111 Umask3 = 0b0000_1111 Umask4 = 0b0000_0111 Uchar1max = (1<<7) - 1 Uchar2max = (1<<11) - 1 Uchar3max = (1<<16) - 1 Ucharerr = 0xFFFD # unicode "replacement char" Ustrerr = "\xef\xbf\xbd" # unicode "replacement char" Usurrself = 0x10000 Usurr1 = 0xd800 Usurr2 = 0xdc00 Usurr3 = 0xe000 Spc = ' '[0] Unesc = {?b=>?\b, ?f=>?\f, ?n=>?\n, ?r=>?\r, ?t=>?\t} end end