module Spring::OkJson
Constants
- Spc
- Uchar1max
- Uchar2max
- Uchar3max
- Ucharerr
- Umask2
- Umask3
- Umask4
- Umaskx
- Unesc
- Upstream
- Ustrerr
- Usurr1
- Usurr2
- Usurr3
- Usurrself
- Utag2
- Utag3
- Utag4
- Utag5
- Utagx
Public Instance Methods
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/spring/json.rb, line 68 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.
# File lib/spring/json.rb, line 87 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
# File lib/spring/json.rb, line 97 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 raise Error, "cannot encode #{x.class}: #{x.inspect}" end end
Private Instance Methods
# File lib/spring/json.rb, line 313 def abbrev(s) t = s[0,10] p = t['`'] t = t[0,p] if p t = t + '...' if t.length < s.length '`' + t + '`' end
# File lib/spring/json.rb, line 456 def arrenc(a) '[' + a.map{|x| valenc(x)}.join(',') + ']' end
Parses an “array” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.
# File lib/spring/json.rb, line 197 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
# File lib/spring/json.rb, line 225 def eat(typ, ts) if ts[0][0] != typ raise Error, "expected #{typ} (got #{ts[0].inspect})" end ts[1..-1] end
# File lib/spring/json.rb, line 285 def falsetok(s); s[0,5] == 'false' ? [:val, 'false', false] : [] end
# File lib/spring/json.rb, line 420 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
# File lib/spring/json.rb, line 461 def keyenc(k) case k when String then strenc(k) else raise Error, "Hash key is not a string: #{k.inspect}" end end
Scans s and returns a list of json tokens, excluding white space (as defined in RFC 4627).
# File lib/spring/json.rb, line 235 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
# File lib/spring/json.rb, line 441 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
# File lib/spring/json.rb, line 283 def nulltok(s); s[0,4] == 'null' ? [:val, 'null', nil] : [] end
# File lib/spring/json.rb, line 513 def numenc(x) if ((x.nan? || x.infinite?) rescue false) raise Error, "Numeric cannot be represented: #{x}" end "#{x}" end
# File lib/spring/json.rb, line 288 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**Integer(m[3][1..-1]))] end else [] end end
# File lib/spring/json.rb, line 451 def objenc(x) '{' + x.map{|k,v| keyenc(k) + ':' + valenc(v)}.join(',') + '}' end
Parses an “object” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.
# File lib/spring/json.rb, line 154 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.
# File lib/spring/json.rb, line 184 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
# File lib/spring/json.rb, line 591 def rubydoesenc? ::String.method_defined?(:force_encoding) end
# File lib/spring/json.rb, line 470 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
# File lib/spring/json.rb, line 304 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
# File lib/spring/json.rb, line 428 def subst(u1, u2) if Usurr1 <= u1 && u1 < Usurr2 && Usurr2 <= u2 && u2 < Usurr3 return ((u1-Usurr1)<<10) | (u2-Usurr2) + Usurrself end return Ucharerr end
# File lib/spring/json.rb, line 436 def surrogate?(u) Usurr1 <= u && u < Usurr3 end
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/spring/json.rb, line 119 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
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.
# File lib/spring/json.rb, line 264 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
# File lib/spring/json.rb, line 284 def truetok(s); s[0,4] == 'true' ? [:val, 'true', true] : [] 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.
# File lib/spring/json.rb, line 526 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
Encodes unicode character u as UTF-8 bytes in string a at position i. Returns the number of bytes written.
# File lib/spring/json.rb, line 397 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
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.
# File lib/spring/json.rb, line 325 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
Parses a “value” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.
# File lib/spring/json.rb, line 136 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