Scratch pad for my safe-stringify method.

JSON-safeStringify2.js

var _ = require('underscore');
var escape = require('escape-html');

function ord(string) {
  return string;
  //return '' + string.charCodeAt();
}

function pad(string, zeros) {
  var count = zeros - string.length;
  while (count) {
    string = '0' + string;
    count--;
  }
  return string;
}

var jsEscapes = {
  '\\': '\\u005c',
  '\'': '\\u0027',
  '"': '\\u0022',
  '>': '\\u003E',
  '<': '\\u003C',
  '&': '\\u0026',
  '=': '\\u003D',
  '-': '\\u002D',
  ';': '\\u003B',
  '\u2028': '\\u2028',
  '\u2029': '\\u2029',
};

// Excape every ASCII character with a value less than 32.
_.times(32, function (z) {
  jsEscapes[String.fromCharCode(z)] = '\\u' + pad(z.toString(16), 4);
});

function recur(item) {
  var ret;
  if (_.isObject(item) || _.isArray(item)) {
    if (item.toJSON) {
      ret = item = item.toJSON();
    } else {
      ret = new item.constructor();
    }
    _.each(item, function (val, key) {
      ret[key] = recur(val);
    });
  } else if (_.isString(item)) {
    ret = escape(item);
  } else {
    ret = item;
  }
  return ret;
}

module.exports = {
  stringify: function (item) {
    return JSON.stringify(item);
  },
  safeStringify: function (item) {
    var string = JSON.stringify(item);
    var safe = '';
    var pos = 0;

    for (var i = 0; i < string.length; i++) {
      if (ch = jsEscapes[string[i]]) {
        safe += string.slice(pos, i) + ch;
        pos = i + 1;
      }
    }
    safe += string.slice(pos);

    console.log(safe);
    return safe;
  },
  parse: function () {
    return JSON.parse.apply(JSON, arguments);
  },
};

// python

/*
_js_escapes = {
    ord('\\'): '\\u005C',
    ord('\''): '\\u0027',
    ord('"'): '\\u0022',
    ord('>'): '\\u003E',
    ord('<'): '\\u003C',
    ord('&'): '\\u0026',
    ord('='): '\\u003D',
    ord('-'): '\\u002D',
    ord(';'): '\\u003B',
    ord('\u2028'): '\\u2028',
    ord('\u2029'): '\\u2029'
}

# Escape every ASCII character with a value less than 32.
_js_escapes.update((ord('%c' % z), '\\u%04X' % z) for z in range(32))


def escapejs(value):
    """Hex encodes characters for use in JavaScript strings."""
    return mark_safe(force_text(value).translate(_js_escapes))
escapejs = allow_lazy(escapejs, six.text_type, SafeText)
*/