* lib/json.rb, lib/json, ext/json, test/json:

  import JSON library.


git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@12428 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 562 insertions, 0 deletions

diff --git a/lib/json/pure/generator.rb b/lib/json/pure/generator.rb
new file mode 100644
index 000000000..498d78a66
--- /dev/null
+++ b/lib/json/pure/generator.rb
@@ -0,0 +1,321 @@
+module JSON
+  MAP = {
+    "\x0" => '\u0000',
+    "\x1" => '\u0001',
+    "\x2" => '\u0002',
+    "\x3" => '\u0003',
+    "\x4" => '\u0004',
+    "\x5" => '\u0005',
+    "\x6" => '\u0006',
+    "\x7" => '\u0007',
+    "\b"  =>  '\b',
+    "\t"  =>  '\t',
+    "\n"  =>  '\n',
+    "\xb" => '\u000b',
+    "\f"  =>  '\f',
+    "\r"  =>  '\r',
+    "\xe" => '\u000e',
+    "\xf" => '\u000f',
+    "\x10" => '\u0010',
+    "\x11" => '\u0011',
+    "\x12" => '\u0012',
+    "\x13" => '\u0013',
+    "\x14" => '\u0014',
+    "\x15" => '\u0015',
+    "\x16" => '\u0016',
+    "\x17" => '\u0017',
+    "\x18" => '\u0018',
+    "\x19" => '\u0019',
+    "\x1a" => '\u001a',
+    "\x1b" => '\u001b',
+    "\x1c" => '\u001c',
+    "\x1d" => '\u001d',
+    "\x1e" => '\u001e',
+    "\x1f" => '\u001f',
+    '"'   =>  '\"',
+    '\\'  =>  '\\\\',
+    '/'   =>  '\/',
+  } # :nodoc:
+
+  # Convert a UTF8 encoded Ruby string _string_ to a JSON string, encoded with
+  # UTF16 big endian characters as \u????, and return it.
+  def utf8_to_json(string) # :nodoc:
+    string = string.gsub(/["\\\/\x0-\x1f]/) { |c| MAP[c] }
+    string.gsub!(/(
+                    (?:
+                      [\xc2-\xdf][\x80-\xbf]    |
+                      [\xe0-\xef][\x80-\xbf]{2} |
+                      [\xf0-\xf4][\x80-\xbf]{3}
+                    )+ |
+                    [\x80-\xc1\xf5-\xff]       # invalid
+                  )/nx) { |c|
+      c.size == 1 and raise GeneratorError, "invalid utf8 byte: '#{c}'"
+      s = JSON::UTF8toUTF16.iconv(c).unpack('H*')[0]
+      s.gsub!(/.{4}/n, '\\\\u\&')
+    }
+    string
+  rescue Iconv::Failure => e
+    raise GeneratorError, "Caught #{e.class}: #{e}"
+  end
+  module_function :utf8_to_json
+
+  module Pure
+    module Generator
+      # This class is used to create State instances, that are use to hold data
+      # while generating a JSON text from a a Ruby data structure.
+      class State
+        # Creates a State object from _opts_, which ought to be Hash to create
+        # a new State instance configured by _opts_, something else to create
+        # an unconfigured instance. If _opts_ is a State object, it is just
+        # returned.
+        def self.from_state(opts)
+          case opts
+          when self
+            opts
+          when Hash
+            new(opts)
+          else
+            new
+          end
+        end
+
+        # Instantiates a new State object, configured by _opts_.
+        #
+        # _opts_ can have the following keys:
+        #
+        # * *indent*: a string used to indent levels (default: ''),
+        # * *space*: a string that is put after, a : or , delimiter (default: ''),
+        # * *space_before*: a string that is put before a : pair delimiter (default: ''),
+        # * *object_nl*: a string that is put at the end of a JSON object (default: ''), 
+        # * *array_nl*: a string that is put at the end of a JSON array (default: ''),
+        # * *check_circular*: true if checking for circular data structures
+        #   should be done, false (the default) otherwise.
+        def initialize(opts = {})
+          @indent         = opts[:indent]       || ''
+          @space          = opts[:space]        || ''
+          @space_before   = opts[:space_before] || ''
+          @object_nl      = opts[:object_nl]    || ''
+          @array_nl       = opts[:array_nl]     || ''
+          @check_circular = !!(opts[:check_circular] || false)
+          @seen           = {}
+        end
+
+        # This string is used to indent levels in the JSON text.
+        attr_accessor :indent
+
+        # This string is used to insert a space between the tokens in a JSON
+        # string.
+        attr_accessor :space
+
+        # This string is used to insert a space before the ':' in JSON objects.
+        attr_accessor :space_before
+
+        # This string is put at the end of a line that holds a JSON object (or
+        # Hash).
+        attr_accessor :object_nl
+
+        # This string is put at the end of a line that holds a JSON array.
+        attr_accessor :array_nl
+
+        # Returns true, if circular data structures should be checked,
+        # otherwise returns false.
+        def check_circular?
+          @check_circular
+        end
+
+        # Returns _true_, if _object_ was already seen during this generating
+        # run. 
+        def seen?(object)
+          @seen.key?(object.__id__)
+        end
+
+        # Remember _object_, to find out if it was already encountered (if a
+        # cyclic data structure is if a cyclic data structure is rendered). 
+        def remember(object)
+          @seen[object.__id__] = true
+        end
+
+        # Forget _object_ for this generating run.
+        def forget(object)
+          @seen.delete object.__id__
+        end
+      end
+
+      module GeneratorMethods
+        module Object
+          # Converts this object to a string (calling #to_s), converts
+          # it to a JSON string, and returns the result. This is a fallback, if no
+          # special method #to_json was defined for some object.
+          def to_json(*) to_s.to_json end
+        end
+
+        module Hash
+          # Returns a JSON string containing a JSON object, that is unparsed from
+          # this Hash instance.
+          # _state_ is a JSON::State object, that can also be used to configure the
+          # produced JSON string output further.
+          # _depth_ is used to find out nesting depth, to indent accordingly.
+          def to_json(state = nil, depth = 0, *)
+            if state
+              state = JSON.state.from_state(state)
+              json_check_circular(state) { json_transform(state, depth) }
+            else
+              json_transform(state, depth)
+            end
+          end
+
+          private
+
+          def json_check_circular(state)
+            if state
+              state.seen?(self) and raise JSON::CircularDatastructure,
+                  "circular data structures not supported!"
+              state.remember self
+            end
+            yield
+          ensure
+            state and state.forget self
+          end
+
+          def json_shift(state, depth)
+            state and not state.object_nl.empty? or return ''
+            state.indent * depth
+          end
+
+          def json_transform(state, depth)
+            delim = ','
+            delim << state.object_nl if state
+            result = '{'
+            result << state.object_nl if state
+            result << map { |key,value|
+              s = json_shift(state, depth + 1)
+              s << key.to_s.to_json(state, depth + 1)
+              s << state.space_before if state
+              s << ':'
+              s << state.space if state
+              s << value.to_json(state, depth + 1)
+            }.join(delim)
+            result << state.object_nl if state
+            result << json_shift(state, depth)
+            result << '}'
+            result
+          end
+        end
+
+        module Array
+          # Returns a JSON string containing a JSON array, that is unparsed from
+          # this Array instance.
+          # _state_ is a JSON::State object, that can also be used to configure the
+          # produced JSON string output further.
+          # _depth_ is used to find out nesting depth, to indent accordingly.
+          def to_json(state = nil, depth = 0, *)
+            if state
+              state = JSON.state.from_state(state)
+              json_check_circular(state) { json_transform(state, depth) }
+            else
+              json_transform(state, depth)
+            end
+          end
+
+          private
+
+          def json_check_circular(state)
+            if state
+              state.seen?(self) and raise JSON::CircularDatastructure,
+                "circular data structures not supported!"
+              state.remember self
+            end
+            yield
+          ensure
+            state and state.forget self
+          end
+
+          def json_shift(state, depth)
+            state and not state.array_nl.empty? or return ''
+            state.indent * depth
+          end
+
+          def json_transform(state, depth)
+            delim = ','
+            delim << state.array_nl if state
+            result = '['
+            result << state.array_nl if state
+            result << map { |value|
+              json_shift(state, depth + 1) << value.to_json(state, depth + 1)
+            }.join(delim)
+            result << state.array_nl if state
+            result << json_shift(state, depth) 
+            result << ']'
+            result
+          end
+        end
+
+        module Integer
+          # Returns a JSON string representation for this Integer number.
+          def to_json(*) to_s end
+        end
+
+        module Float
+          # Returns a JSON string representation for this Float number.
+          def to_json(*) to_s end
+        end
+
+        module String
+          # This string should be encoded with UTF-8 A call to this method
+          # returns a JSON string encoded with UTF16 big endian characters as
+          # \u????.
+          def to_json(*)
+            '"' << JSON.utf8_to_json(self) << '"'
+          end
+
+          # Module that holds the extinding methods if, the String module is
+          # included.
+          module Extend
+            # Raw Strings are JSON Objects (the raw bytes are stored in an array for the
+            # key "raw"). The Ruby String can be created by this module method.
+            def json_create(o)
+              o['raw'].pack('C*')
+            end
+          end
+
+          # Extends _modul_ with the String::Extend module.
+          def self.included(modul)
+            modul.extend Extend
+          end
+
+          # This method creates a raw object hash, that can be nested into
+          # other data structures and will be unparsed as a raw string. This
+          # method should be used, if you want to convert raw strings to JSON
+          # instead of UTF-8 strings, e. g. binary data.
+          def to_json_raw_object
+            {
+              JSON.create_id  => self.class.name,
+              'raw'           => self.unpack('C*'),
+            }
+          end
+
+          # This method creates a JSON text from the result of
+          # a call to to_json_raw_object of this String.
+          def to_json_raw(*args)
+            to_json_raw_object.to_json(*args)
+          end
+        end
+
+        module TrueClass
+          # Returns a JSON string for true: 'true'.
+          def to_json(*) 'true' end
+        end
+
+        module FalseClass
+          # Returns a JSON string for false: 'false'.
+          def to_json(*) 'false' end
+        end
+
+        module NilClass
+          # Returns a JSON string for nil: 'null'.
+          def to_json(*) 'null' end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/json/pure/parser.rb b/lib/json/pure/parser.rb
new file mode 100644
index 000000000..6118fe489
--- /dev/null
+++ b/lib/json/pure/parser.rb
@@ -0,0 +1,241 @@
+require 'strscan'
+
+module JSON
+  module Pure
+    # This class implements the JSON parser that is used to parse a JSON string
+    # into a Ruby data structure.
+    class Parser < StringScanner
+      STRING                = /" ((?:[^\x0-\x1f"\\] |
+                                  \\["\\\/bfnrt] |
+                                  \\u[0-9a-fA-F]{4} |
+                                  \\[\x20-\xff])*)
+                              "/nx
+      INTEGER               = /(-?0|-?[1-9]\d*)/
+      FLOAT                 = /(-?
+                                (?:0|[1-9]\d*)
+                                (?:
+                                  \.\d+(?i:e[+-]?\d+) |
+                                  \.\d+ |
+                                  (?i:e[+-]?\d+)
+                                )
+                                )/x
+      OBJECT_OPEN           = /\{/
+      OBJECT_CLOSE          = /\}/
+      ARRAY_OPEN            = /\[/
+      ARRAY_CLOSE           = /\]/
+      PAIR_DELIMITER        = /:/
+      COLLECTION_DELIMITER  = /,/
+      TRUE                  = /true/
+      FALSE                 = /false/
+      NULL                  = /null/
+      IGNORE                = %r(
+        (?:
+         //[^\n\r]*[\n\r]| # line comments
+         /\*               # c-style comments
+         (?:
+          [^*/]|        # normal chars
+          /[^*]|        # slashes that do not start a nested comment
+          \*[^/]|       # asterisks that do not end this comment
+          /(?=\*/)      # single slash before this comment's end 
+         )*
+           \*/               # the End of this comment
+           |[ \t\r\n]+       # whitespaces: space, horicontal tab, lf, cr
+        )+
+      )mx
+
+      UNPARSED = Object.new
+
+      # Creates a new JSON::Pure::Parser instance for the string _source_.
+      #
+      # It will be configured by the _opts_ hash. _opts_ can have the following
+      # keys:
+      # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
+      #   structures. Disable depth checking with :max_nesting => false.
+      def initialize(source, opts = {})
+        super
+        if !opts.key?(:max_nesting) # defaults to 19
+          @max_nesting = 19
+        elsif opts[:max_nesting]
+          @max_nesting = opts[:max_nesting]
+        else
+          @max_nesting = 0
+        end
+        @create_id = JSON.create_id
+      end
+
+      alias source string
+
+      # Parses the current JSON string _source_ and returns the complete data
+      # structure as a result.
+      def parse
+        reset
+        obj = nil
+        until eos?
+          case
+          when scan(OBJECT_OPEN)
+            obj and raise ParserError, "source '#{peek(20)}' not in JSON!"
+            @current_nesting = 1
+            obj = parse_object
+          when scan(ARRAY_OPEN)
+            obj and raise ParserError, "source '#{peek(20)}' not in JSON!"
+            @current_nesting = 1
+            obj = parse_array
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "source '#{peek(20)}' not in JSON!"
+          end
+        end
+        obj or raise ParserError, "source did not contain any JSON!"
+        obj
+      end
+
+      private
+
+      # Unescape characters in strings.
+      UNESCAPE_MAP = Hash.new { |h, k| h[k] = k.chr }
+      UNESCAPE_MAP.update({
+        ?"  => '"',
+        ?\\ => '\\',
+        ?/  => '/',
+        ?b  => "\b",
+        ?f  => "\f",
+        ?n  => "\n",
+        ?r  => "\r",
+        ?t  => "\t",
+        ?u  => nil, 
+      })
+
+      def parse_string
+        if scan(STRING)
+          return '' if self[1].empty?
+          self[1].gsub(%r((?:\\[\\bfnrt"/]|(?:\\u(?:[A-Fa-f\d]{4}))+|\\[\x20-\xff]))n) do |c|
+            if u = UNESCAPE_MAP[c[1]]
+              u
+            else # \uXXXX
+              bytes = ''
+              i = 0
+              while c[6 * i] == ?\\ && c[6 * i + 1] == ?u 
+                bytes << c[6 * i + 2, 2].to_i(16) << c[6 * i + 4, 2].to_i(16)
+                i += 1
+              end
+              JSON::UTF16toUTF8.iconv(bytes)
+            end
+          end
+        else
+          UNPARSED
+        end
+      rescue Iconv::Failure => e
+        raise GeneratorError, "Caught #{e.class}: #{e}"
+      end
+
+      def parse_value
+        case
+        when scan(FLOAT)
+          Float(self[1])
+        when scan(INTEGER)
+          Integer(self[1])
+        when scan(TRUE)
+          true
+        when scan(FALSE)
+          false
+        when scan(NULL)
+          nil
+        when (string = parse_string) != UNPARSED
+          string
+        when scan(ARRAY_OPEN)
+          @current_nesting += 1
+          ary = parse_array
+          @current_nesting -= 1
+          ary
+        when scan(OBJECT_OPEN)
+          @current_nesting += 1
+          obj = parse_object
+          @current_nesting -= 1
+          obj
+        else
+          UNPARSED
+        end
+      end
+
+      def parse_array
+        raise NestingError, "nesting of #@current_nesting is to deep" if
+          @max_nesting.nonzero? && @current_nesting > @max_nesting
+        result = []
+        delim = false
+        until eos?
+          case
+          when (value = parse_value) != UNPARSED
+            delim = false
+            result << value
+            skip(IGNORE)
+            if scan(COLLECTION_DELIMITER)
+              delim = true
+            elsif match?(ARRAY_CLOSE)
+              ;
+            else
+              raise ParserError, "expected ',' or ']' in array at '#{peek(20)}'!"
+            end
+          when scan(ARRAY_CLOSE)
+            if delim
+              raise ParserError, "expected next element in array at '#{peek(20)}'!"
+            end
+            break
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "unexpected token in array at '#{peek(20)}'!"
+          end
+        end
+        result
+      end
+
+      def parse_object
+        raise NestingError, "nesting of #@current_nesting is to deep" if
+          @max_nesting.nonzero? && @current_nesting > @max_nesting
+        result = {}
+        delim = false
+        until eos?
+          case
+          when (string = parse_string) != UNPARSED
+            skip(IGNORE)
+            unless scan(PAIR_DELIMITER)
+              raise ParserError, "expected ':' in object at '#{peek(20)}'!"
+            end
+            skip(IGNORE)
+            unless (value = parse_value).equal? UNPARSED
+              result[string] = value
+              delim = false
+              skip(IGNORE)
+              if scan(COLLECTION_DELIMITER)
+                delim = true
+              elsif match?(OBJECT_CLOSE)
+                ;
+              else
+                raise ParserError, "expected ',' or '}' in object at '#{peek(20)}'!"
+              end
+            else
+              raise ParserError, "expected value in object at '#{peek(20)}'!"
+            end
+          when scan(OBJECT_CLOSE)
+            if delim
+              raise ParserError, "expected next name, value pair in object at '#{peek(20)}'!"
+            end
+            if klassname = result[@create_id]
+              klass = JSON.deep_const_get klassname
+              break unless klass and klass.json_creatable?
+              result = klass.json_create(result)
+              result
+            end
+            break
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "unexpected token in object at '#{peek(20)}'!"
+          end
+        end
+        result
+      end
+    end
+  end
+end