clarinet.js

;(function (clarinet) {
  "use strict";

  // non node-js needs to set clarinet debug on root
  var env =(typeof process === 'object' && process.env)
    ? process.env
    : self;

  clarinet.parser            = function (opt) { return new CParser(opt);};
  clarinet.CParser           = CParser;
  clarinet.CStream           = CStream;
  clarinet.createStream      = createStream;
  clarinet.MAX_BUFFER_LENGTH = 64 * 1024;
  clarinet.DEBUG             = (env.CDEBUG==='debug');
  clarinet.INFO              = (env.CDEBUG==='debug' || env.CDEBUG==='info');
  clarinet.EVENTS            =
    [ "value"
    , "string"
    , "key"
    , "openobject"
    , "closeobject"
    , "openarray"
    , "closearray"
    , "error"
    , "end"
    , "ready"
    ];

  var buffers     = {
        textNode: undefined,
        numberNode: ""
    }
    , streamWraps = clarinet.EVENTS.filter(function (ev) {
          return ev !== "error" && ev !== "end";
        })
    , S           = 0
    , Stream
    ;

  clarinet.STATE =
    { BEGIN                             : S++
    , VALUE                             : S++ // general stuff
    , OPEN_OBJECT                       : S++ // {
    , CLOSE_OBJECT                      : S++ // }
    , OPEN_ARRAY                        : S++ // [
    , CLOSE_ARRAY                       : S++ // ]
    , TEXT_ESCAPE                       : S++ // \ stuff
    , STRING                            : S++ // ""
    , BACKSLASH                         : S++
    , END                               : S++ // No more stack
    , OPEN_KEY                          : S++ // , "a"
    , CLOSE_KEY                         : S++ // :
    , TRUE                              : S++ // r
    , TRUE2                             : S++ // u
    , TRUE3                             : S++ // e
    , FALSE                             : S++ // a
    , FALSE2                            : S++ // l
    , FALSE3                            : S++ // s
    , FALSE4                            : S++ // e
    , NULL                              : S++ // u
    , NULL2                             : S++ // l
    , NULL3                             : S++ // l
    , NUMBER_DECIMAL_POINT              : S++ // .
    , NUMBER_DIGIT                      : S++ // [0-9]
    };

  for (var s_ in clarinet.STATE) clarinet.STATE[clarinet.STATE[s_]] = s_;

  // switcharoo
  S = clarinet.STATE;

  const Char = {
    tab                 : 0x09,     // \t
    lineFeed            : 0x0A,     // \n
    carriageReturn      : 0x0D,     // \r
    space               : 0x20,     // " "

    doubleQuote         : 0x22,     // "
    plus                : 0x2B,     // +
    comma               : 0x2C,     // ,
    minus               : 0x2D,     // -
    period              : 0x2E,     // .

    _0                  : 0x30,     // 0
    _9                  : 0x39,     // 9

    colon               : 0x3A,     // :

    E                   : 0x45,     // E

    openBracket         : 0x5B,     // [
    backslash           : 0x5C,     // \
    closeBracket        : 0x5D,     // ]

    a                   : 0x61,     // a
    b                   : 0x62,     // b
    e                   : 0x65,     // e 
    f                   : 0x66,     // f
    l                   : 0x6C,     // l
    n                   : 0x6E,     // n
    r                   : 0x72,     // r
    s                   : 0x73,     // s
    t                   : 0x74,     // t
    u                   : 0x75,     // u

    openBrace           : 0x7B,     // {
    closeBrace          : 0x7D,     // }
  }

  if (!Object.create) {
    Object.create = function (o) {
      function f () { this["__proto__"] = o; }
      f.prototype = o;
      return new f;
    };
  }

  if (!Object.getPrototypeOf) {
    Object.getPrototypeOf = function (o) {
      return o["__proto__"];
    };
  }

  if (!Object.keys) {
    Object.keys = function (o) {
      var a = [];
      for (var i in o) if (o.hasOwnProperty(i)) a.push(i);
      return a;
    };
  }

  function checkBufferLength (parser) {
    var maxAllowed = Math.max(clarinet.MAX_BUFFER_LENGTH, 10)
      , maxActual = 0
      ;
    for (var buffer in buffers) {
      var len = parser[buffer] === undefined ? 0 : parser[buffer].length;
      if (len > maxAllowed) {
        switch (buffer) {
          case "text":
            closeText(parser);
          break;

          default:
            error(parser, "Max buffer length exceeded: "+ buffer);
        }
      }
      maxActual = Math.max(maxActual, len);
    }
    parser.bufferCheckPosition = (clarinet.MAX_BUFFER_LENGTH - maxActual)
                               + parser.position;
  }

  function clearBuffers (parser) {
    for (var buffer in buffers) {
      parser[buffer] = buffers[buffer];
    }
  }

  var stringTokenPattern = /[\\"\n]/g;

  function CParser (opt) {
    if (!(this instanceof CParser)) return new CParser (opt);

    var parser = this;
    clearBuffers(parser);
    parser.bufferCheckPosition = clarinet.MAX_BUFFER_LENGTH;
    parser.q        = parser.c = parser.p = "";
    parser.opt      = opt || {};
    parser.closed   = parser.closedRoot = parser.sawRoot = false;
    parser.tag      = parser.error = null;
    parser.state    = S.BEGIN;
    parser.stack    = new Array();
    // mostly just for error reporting
    parser.position = parser.column = 0;
    parser.line     = 1;
    parser.slashed  = false;
    parser.unicodeI = 0;
    parser.unicodeS = null;
    parser.depth    = 0;
    emit(parser, "onready");
  }

  CParser.prototype =
    { end    : function () { end(this); }
    , write  : write
    , resume : function () { this.error = null; return this; }
    , close  : function () { return this.write(null); }
    };

  try        { Stream = require("stream").Stream; }
  catch (ex) { Stream = function () {}; }

  function createStream (opt) { return new CStream(opt); }

  function CStream (opt) {
    if (!(this instanceof CStream)) return new CStream(opt);

    this._parser = new CParser(opt);
    this.writable = true;
    this.readable = true;

    //var Buffer = this.Buffer || function Buffer () {}; // if we don't have Buffers, fake it so we can do `var instanceof Buffer` and not throw an error
    this.bytes_remaining = 0; // number of bytes remaining in multi byte utf8 char to read after split boundary
    this.bytes_in_sequence = 0; // bytes in multi byte utf8 char to read
    this.temp_buffs = { "2": new Buffer(2), "3": new Buffer(3), "4": new Buffer(4) }; // for rebuilding chars split before boundary is reached
    this.string = '';

    var me = this;
    Stream.apply(me);

    this._parser.onend = function () { me.emit("end"); };
    this._parser.onerror = function (er) {
      me.emit("error", er);
      me._parser.error = null;
    };

    streamWraps.forEach(function (ev) {
      Object.defineProperty(me, "on" + ev,
        { get          : function () { return me._parser["on" + ev]; }
        , set          : function (h) {
            if (!h) {
              me.removeAllListeners(ev);
              me._parser["on"+ev] = h;
              return h;
            }
            me.on(ev, h);
          }
        , enumerable   : true
        , configurable : false
        });
    });
  }

  CStream.prototype = Object.create(Stream.prototype,
    { constructor: { value: CStream } });

  CStream.prototype.write = function (data) {
    data = new Buffer(data);
    for (var i = 0; i < data.length; i++) {
      var n = data[i];

      // check for carry over of a multi byte char split between data chunks
      // & fill temp buffer it with start of this data chunk up to the boundary limit set in the last iteration
      if (this.bytes_remaining > 0) {
        for (var j = 0; j < this.bytes_remaining; j++) {
          this.temp_buffs[this.bytes_in_sequence][this.bytes_in_sequence - this.bytes_remaining + j] = data[j];
        }
        this.string = this.temp_buffs[this.bytes_in_sequence].toString();
        this.bytes_in_sequence = this.bytes_remaining = 0;

        // move iterator forward by number of byte read during sequencing
        i = i + j - 1;

        // pass data to parser and move forward to parse rest of data
        this._parser.write(this.string);
        this.emit("data", this.string);
        continue;
      }

      // if no remainder bytes carried over, parse multi byte (>=128) chars one at a time
      if (this.bytes_remaining === 0 && n >= 128) {
        if ((n >= 194) && (n <= 223)) this.bytes_in_sequence = 2;
        if ((n >= 224) && (n <= 239)) this.bytes_in_sequence = 3;
        if ((n >= 240) && (n <= 244)) this.bytes_in_sequence = 4;
        if ((this.bytes_in_sequence + i) > data.length) { // if bytes needed to complete char fall outside data length, we have a boundary split

          for (var k = 0; k <= (data.length - 1 - i); k++) {
            this.temp_buffs[this.bytes_in_sequence][k] = data[i + k]; // fill temp data of correct size with bytes available in this chunk
          }
          this.bytes_remaining = (i + this.bytes_in_sequence) - data.length;

          // immediately return as we need another chunk to sequence the character
          return true;
        } else {
          this.string = data.slice(i, (i + this.bytes_in_sequence)).toString();
          i = i + this.bytes_in_sequence - 1;

          this._parser.write(this.string);
          this.emit("data", this.string);
          continue;
        }
      }

      // is there a range of characters that are immediately parsable?
      for (var p = i; p < data.length; p++) {
        if (data[p] >= 128) break;
      }
      this.string = data.slice(i, p).toString();
      this._parser.write(this.string);
      this.emit("data", this.string);
      i = p - 1;

      // handle any remaining characters using multibyte logic
      continue;
    }
  };

  CStream.prototype.end = function (chunk) {
    if (chunk && chunk.length) this._parser.write(chunk.toString());
    this._parser.end();
    return true;
  };

  CStream.prototype.on = function (ev, handler) {
    var me = this;
    if (!me._parser["on"+ev] && streamWraps.indexOf(ev) !== -1) {
      me._parser["on"+ev] = function () {
        var args = arguments.length === 1 ? [arguments[0]]
                 : Array.apply(null, arguments);
        args.splice(0, 0, ev);
        me.emit.apply(me, args);
      };
    }
    return Stream.prototype.on.call(me, ev, handler);
  };

  CStream.prototype.destroy = function () {
    clearBuffers(this._parser);
    this.emit("close");
  };

  function emit(parser, event, data) {
    if(clarinet.INFO) console.log('-- emit', event, data);
    if (parser[event]) parser[event](data);
  }

  function emitNode(parser, event, data) {
    closeValue(parser);
    emit(parser, event, data);
  }

  function closeValue(parser, event) {
    parser.textNode = textopts(parser.opt, parser.textNode);
    if (parser.textNode !== undefined) {
      emit(parser, (event ? event : "onvalue"), parser.textNode);
    }
    parser.textNode = undefined;
  }

  function closeNumber(parser) {
    if (parser.numberNode)
      emit(parser, "onvalue", parseFloat(parser.numberNode));
    parser.numberNode = "";
  }

  function textopts (opt, text) {
    if (text === undefined) {
      return text;
    }
    if (opt.trim) text = text.trim();
    if (opt.normalize) text = text.replace(/\s+/g, " ");
    return text;
  }

  function error (parser, er) {
    closeValue(parser);
    er += "\nLine: "+parser.line+
          "\nColumn: "+parser.column+
          "\nChar: "+parser.c;
    er = new Error(er);
    parser.error = er;
    emit(parser, "onerror", er);
    return parser;
  }

  function end(parser) {
    if (parser.state !== S.VALUE || parser.depth !== 0)
      error(parser, "Unexpected end");

    closeValue(parser);
    parser.c      = "";
    parser.closed = true;
    emit(parser, "onend");
    CParser.call(parser, parser.opt);
    return parser;
  }

  function isWhitespace(c) {
    return c === Char.carriageReturn || c === Char.lineFeed || c === Char.space || c === Char.tab;
  }

  function write (chunk) {
    var parser = this;
    if (this.error) throw this.error;
    if (parser.closed) return error(parser,
      "Cannot write after close. Assign an onready handler.");
    if (chunk === null) return end(parser);
    var i = 0, c = chunk.charCodeAt(0), p = parser.p;
    if (clarinet.DEBUG) console.log('write -> [' + chunk + ']');
    while (c) {
      p = c;
      parser.c = c = chunk.charCodeAt(i++);
      // if chunk doesnt have next, like streaming char by char
      // this way we need to check if previous is really previous
      // if not we need to reset to what the parser says is the previous
      // from buffer
      if(p !== c ) parser.p = p;
      else p = parser.p;

      if(!c) break;

      if (clarinet.DEBUG) console.log(i,c,clarinet.STATE[parser.state]);
      parser.position ++;
      if (c === Char.lineFeed) {
        parser.line ++;
        parser.column = 0;
      } else parser.column ++;
      switch (parser.state) {

        case S.BEGIN:
          if (c === Char.openBrace) parser.state = S.OPEN_OBJECT;
          else if (c === Char.openBracket) parser.state = S.OPEN_ARRAY;
          else if (!isWhitespace(c))
            error(parser, "Non-whitespace before {[.");
        continue;

        case S.OPEN_KEY:
        case S.OPEN_OBJECT:
          if (isWhitespace(c)) continue;
          if(parser.state === S.OPEN_KEY) parser.stack.push(S.CLOSE_KEY);
          else {
            if(c === Char.closeBrace) {
              emit(parser, 'onopenobject');
              this.depth++;
              emit(parser, 'oncloseobject');
              this.depth--;
              parser.state = parser.stack.pop() || S.VALUE;
              continue;
            } else  parser.stack.push(S.CLOSE_OBJECT);
          }
          if(c === Char.doubleQuote) parser.state = S.STRING;
          else error(parser, "Malformed object key should start with \"");
        continue;

        case S.CLOSE_KEY:
        case S.CLOSE_OBJECT:
          if (isWhitespace(c)) continue;
          var event = (parser.state === S.CLOSE_KEY) ? 'key' : 'object';
          if(c === Char.colon) {
            if(parser.state === S.CLOSE_OBJECT) {
              parser.stack.push(S.CLOSE_OBJECT);
              closeValue(parser, 'onopenobject');
               this.depth++;
            } else closeValue(parser, 'onkey');
            parser.state  = S.VALUE;
          } else if (c === Char.closeBrace) {
            emitNode(parser, 'oncloseobject');
            this.depth--;
            parser.state = parser.stack.pop() || S.VALUE;
          } else if(c === Char.comma) {
            if(parser.state === S.CLOSE_OBJECT)
              parser.stack.push(S.CLOSE_OBJECT);
            closeValue(parser);
            parser.state  = S.OPEN_KEY;
          } else error(parser, 'Bad object');
        continue;

        case S.OPEN_ARRAY: // after an array there always a value
        case S.VALUE:
          if (isWhitespace(c)) continue;
          if(parser.state===S.OPEN_ARRAY) {
            emit(parser, 'onopenarray');
            this.depth++;
            parser.state = S.VALUE;
            if(c === Char.closeBracket) {
              emit(parser, 'onclosearray');
              this.depth--;
              parser.state = parser.stack.pop() || S.VALUE;
              continue;
            } else {
              parser.stack.push(S.CLOSE_ARRAY);
            }
          }
               if(c === Char.doubleQuote) parser.state = S.STRING;
          else if(c === Char.openBrace) parser.state = S.OPEN_OBJECT;
          else if(c === Char.openBracket) parser.state = S.OPEN_ARRAY;
          else if(c === Char.t) parser.state = S.TRUE;
          else if(c === Char.f) parser.state = S.FALSE;
          else if(c === Char.n) parser.state = S.NULL;
          else if(c === Char.minus) { // keep and continue
            parser.numberNode += "-";
          } else if(Char._0 <= c && c <= Char._9) {
            parser.numberNode += String.fromCharCode(c);
            parser.state = S.NUMBER_DIGIT;
          } else               error(parser, "Bad value");
        continue;

        case S.CLOSE_ARRAY:
          if(c === Char.comma) {
            parser.stack.push(S.CLOSE_ARRAY);
            closeValue(parser, 'onvalue');
            parser.state  = S.VALUE;
          } else if (c === Char.closeBracket) {
            emitNode(parser, 'onclosearray');
            this.depth--;
            parser.state = parser.stack.pop() || S.VALUE;
          } else if (isWhitespace(c))
              continue;
          else error(parser, 'Bad array');
        continue;

        case S.STRING:
          if (parser.textNode === undefined) {
            parser.textNode = "";
          }

          // thanks thejh, this is an about 50% performance improvement.
          var starti              = i-1
            , slashed = parser.slashed
            , unicodeI = parser.unicodeI
            ;
          STRING_BIGLOOP: while (true) {
            if (clarinet.DEBUG)
              console.log(i,c,clarinet.STATE[parser.state]
                         ,slashed);
            // zero means "no unicode active". 1-4 mean "parse some more". end after 4.
            while (unicodeI > 0) {
              parser.unicodeS += String.fromCharCode(c);
              c = chunk.charCodeAt(i++);
              parser.position++;
              if (unicodeI === 4) {
                // TODO this might be slow? well, probably not used too often anyway
                parser.textNode += String.fromCharCode(parseInt(parser.unicodeS, 16));
                unicodeI = 0;
                starti = i-1;
              } else {
                unicodeI++;
              }
              // we can just break here: no stuff we skipped that still has to be sliced out or so
              if (!c) break STRING_BIGLOOP;
            }
            if (c === Char.doubleQuote && !slashed) {
              parser.state = parser.stack.pop() || S.VALUE;
              parser.textNode += chunk.substring(starti, i-1);
              parser.position += i - 1 - starti;
              break;
            }
            if (c === Char.backslash && !slashed) {
              slashed = true;
              parser.textNode += chunk.substring(starti, i-1);
              parser.position += i - 1 - starti;
              c = chunk.charCodeAt(i++);
              parser.position++;
              if (!c) break;
            }
            if (slashed) {
              slashed = false;
                   if (c === Char.n) { parser.textNode += '\n'; }
              else if (c === Char.r) { parser.textNode += '\r'; }
              else if (c === Char.t) { parser.textNode += '\t'; }
              else if (c === Char.f) { parser.textNode += '\f'; }
              else if (c === Char.b) { parser.textNode += '\b'; }
              else if (c === Char.u) {
                // \uxxxx. meh!
                unicodeI = 1;
                parser.unicodeS = '';
              } else {
                parser.textNode += String.fromCharCode(c);
              }
              c = chunk.charCodeAt(i++);
              parser.position++;
              starti = i-1;
              if (!c) break;
              else continue;
            }

            stringTokenPattern.lastIndex = i;
            var reResult = stringTokenPattern.exec(chunk);
            if (reResult === null) {
              i = chunk.length+1;
              parser.textNode += chunk.substring(starti, i-1);
              parser.position += i - 1 - starti;
              break;
            }
            i = reResult.index+1;
            c = chunk.charCodeAt(reResult.index);
            if (!c) {
              parser.textNode += chunk.substring(starti, i-1);
              parser.position += i - 1 - starti;
              break;
            }
          }
          parser.slashed = slashed;
          parser.unicodeI = unicodeI;
        continue;

        case S.TRUE:
          if (c === Char.r) parser.state = S.TRUE2;
          else error(parser, 'Invalid true started with t'+ c);
        continue;

        case S.TRUE2:
          if (c === Char.u) parser.state = S.TRUE3;
          else error(parser, 'Invalid true started with tr'+ c);
        continue;

        case S.TRUE3:
          if(c === Char.e) {
            emit(parser, "onvalue", true);
            parser.state = parser.stack.pop() || S.VALUE;
          } else error(parser, 'Invalid true started with tru'+ c);
        continue;

        case S.FALSE:
          if (c === Char.a) parser.state = S.FALSE2;
          else error(parser, 'Invalid false started with f'+ c);
        continue;

        case S.FALSE2:
          if (c === Char.l) parser.state = S.FALSE3;
          else error(parser, 'Invalid false started with fa'+ c);
        continue;

        case S.FALSE3:
          if (c === Char.s) parser.state = S.FALSE4;
          else error(parser, 'Invalid false started with fal'+ c);
        continue;

        case S.FALSE4:
          if (c === Char.e) {
            emit(parser, "onvalue", false);
            parser.state = parser.stack.pop() || S.VALUE;
          } else error(parser, 'Invalid false started with fals'+ c);
        continue;

        case S.NULL:
          if (c === Char.u) parser.state = S.NULL2;
          else error(parser, 'Invalid null started with n'+ c);
        continue;

        case S.NULL2:
          if (c === Char.l) parser.state = S.NULL3;
          else error(parser, 'Invalid null started with nu'+ c);
        continue;

        case S.NULL3:
          if(c === Char.l) {
            emit(parser, "onvalue", null);
            parser.state = parser.stack.pop() || S.VALUE;
          } else error(parser, 'Invalid null started with nul'+ c);
        continue;

        case S.NUMBER_DECIMAL_POINT:
          if(c === Char.period) {
            parser.numberNode += ".";
            parser.state       = S.NUMBER_DIGIT;
          } else error(parser, 'Leading zero not followed by .');
        continue;

        case S.NUMBER_DIGIT:
          if(Char._0 <= c && c <= Char._9) parser.numberNode += String.fromCharCode(c);
          else if (c === Char.period) {
            if(parser.numberNode.indexOf('.')!==-1)
              error(parser, 'Invalid number has two dots');
            parser.numberNode += ".";
          } else if (c === Char.e || c === Char.E) {
            if(parser.numberNode.indexOf('e')!==-1 ||
               parser.numberNode.indexOf('E')!==-1 )
               error(parser, 'Invalid number has two exponential');
            parser.numberNode += "e";
          } else if (c === Char.plus || c === Char.minus) {
            if(!(p === Char.e || p === Char.E))
              error(parser, 'Invalid symbol in number');
            parser.numberNode += String.fromCharCode(c);
          } else {
            closeNumber(parser);
            i--; // go back one
            parser.state = parser.stack.pop() || S.VALUE;
          }
        continue;

        default:
          error(parser, "Unknown state: " + parser.state);
      }
    }
    if (parser.position >= parser.bufferCheckPosition)
      checkBufferLength(parser);
    return parser;
  }

})(typeof exports === "undefined" ? clarinet = {} : exports);