xacro-parser/umd/index.cjs.map

Utility for parsing and converting ROS Xacro files in Javascript.

{"version":3,"file":"index.cjs","sources":["../src/utils.js","../node_modules/expr-eval-fork/dist/index.mjs","../src/ExpressionParser.js","../src/XacroParser.js","../src/XacroLoader.js"],"sourcesContent":["\nexport function getUrlBase(url) {\n    const tokens = url.split(/[\\\\/]/g);\n    tokens.pop();\n    if (tokens.length === 0) {\n        return './';\n    } else {\n        return tokens.join('/') + '/';\n    }\n}\n\n// XML Helpers\n// QuerySelectorAll that respects tag prefixes like 'xacro:'\nexport function getElementsWithName(node, name, res = []) {\n    if (node.tagName === name) {\n        res.push(node);\n    }\n    for (let i = 0, l = node.children.length; i < l; i++) {\n        const child = node.children[i];\n        getElementsWithName(child, name, res);\n    }\n    return res;\n}\n\n// Deep clone an xml node without the macro or property tags.\nexport function deepClone(node, stripPropsMacros) {\n    const cloned = node.cloneNode();\n    const childNodes = node.childNodes;\n    for (let i = 0, l = childNodes.length; i < l; i++) {\n        const child = childNodes[i];\n        const tagName = child.tagName;\n        if (!stripPropsMacros || (tagName !== 'xacro:property' && tagName !== 'xacro:macro')) {\n            cloned.appendChild(deepClone(child, stripPropsMacros));\n        }\n    }\n    return cloned;\n}\n\n// Takes an array of xml elements and removes the last elements that\n// are comments or newlines.\nexport function removeEndCommentsFromArray(arr) {\n    while (arr.length > 0) {\n        const el = arr[arr.length - 1];\n        if (el.nodeType !== el.ELEMENT_NODE) {\n            arr.pop();\n        } else {\n            break;\n        }\n    }\n}\n\n// Expression helpers\nexport function isOperator(str) {\n    const regexp = /^[()/*+\\-%|&=[\\]]+$/;\n    return regexp.test(str);\n}\n\nexport function isString(str) {\n    const regexp = /^(('[^']*?')|(\"[^\"]*?\")|(`[^`]*?`))$/;\n    return regexp.test(str);\n}\n\n// https://stackoverflow.com/a/175787\nexport function isNumber(str) {\n    return !isNaN(Number(str)) && !isNaN(parseFloat(str));\n}\n\n// TODO: this needs to tokenize numbers together\nexport function tokenize(str) {\n    // split text within quotes (', \", `) or operators\n    const regexp = /(('[^']*?')|(\"[^\"]*?\")|(`[^`]*?`)|([()/*+\\-%|!&=]+?))/g;\n    return str\n        .replace(regexp, m => ` ${ m } `)\n        .trim()\n        .split(/\\s+/g);\n}\n\nexport function normalizeExpression(str) {\n    // Remove any instances of \"--\" or \"++\" that might occur from negating a negative number\n    // by adding a space that are not in a string.\n    return str.replace(/[-+]{2,}/, val => {\n        let positive = true;\n        for (let i = 0, l = val.length; i < l; i++) {\n            const operator = val[i];\n            if (operator === '-') {\n                positive = !positive;\n            }\n        }\n\n        return positive ? '+' : '-';\n    });\n}\n\n// Property Set Helpers\nexport const PARENT_SCOPE = Symbol('parent');\n\n// merges a set of properties together into a single set retaining\n// the parent scope link as well.\nexport function mergePropertySets(...args) {\n    const res = {};\n    for (let i = 0, l = args.length; i < l; i++) {\n        const obj = args[i];\n        for (const key in obj) {\n            res[key] = obj[key];\n        }\n        if (PARENT_SCOPE in obj) {\n            res[PARENT_SCOPE] = obj[PARENT_SCOPE];\n        }\n    }\n    return res;\n}\n\n// Copies a property set and creates a link to the original set as a parent scope\nexport function createNewPropertyScope(properties) {\n    const res = mergePropertySets(properties);\n    res[PARENT_SCOPE] = properties;\n    return res;\n}\n","var INUMBER = 'INUMBER';\nvar IOP1 = 'IOP1';\nvar IOP2 = 'IOP2';\nvar IOP3 = 'IOP3';\nvar IVAR = 'IVAR';\nvar IVARNAME = 'IVARNAME';\nvar IFUNCALL = 'IFUNCALL';\nvar IFUNDEF = 'IFUNDEF';\nvar IEXPR = 'IEXPR';\nvar IEXPREVAL = 'IEXPREVAL';\nvar IMEMBER = 'IMEMBER';\nvar IENDSTATEMENT = 'IENDSTATEMENT';\nvar IARRAY = 'IARRAY';\n\nfunction Instruction(type, value) {\n  this.type = type;\n  this.value = (value !== undefined && value !== null) ? value : 0;\n}\n\nInstruction.prototype.toString = function () {\n  switch (this.type) {\n    case INUMBER:\n    case IOP1:\n    case IOP2:\n    case IOP3:\n    case IVAR:\n    case IVARNAME:\n    case IENDSTATEMENT:\n      return this.value;\n    case IFUNCALL:\n      return 'CALL ' + this.value;\n    case IFUNDEF:\n      return 'DEF ' + this.value;\n    case IARRAY:\n      return 'ARRAY ' + this.value;\n    case IMEMBER:\n      return '.' + this.value;\n    default:\n      return 'Invalid Instruction';\n  }\n};\n\nfunction unaryInstruction(value) {\n  return new Instruction(IOP1, value);\n}\n\nfunction binaryInstruction(value) {\n  return new Instruction(IOP2, value);\n}\n\nfunction ternaryInstruction(value) {\n  return new Instruction(IOP3, value);\n}\n\nfunction simplify(tokens, unaryOps, binaryOps, ternaryOps, values) {\n  var nstack = [];\n  var newexpression = [];\n  var n1, n2, n3;\n  var f;\n  for (var i = 0; i < tokens.length; i++) {\n    var item = tokens[i];\n    var type = item.type;\n    if (type === INUMBER || type === IVARNAME) {\n      if (Array.isArray(item.value)) {\n        nstack.push.apply(nstack, simplify(item.value.map(function (x) {\n          return new Instruction(INUMBER, x);\n        }).concat(new Instruction(IARRAY, item.value.length)), unaryOps, binaryOps, ternaryOps, values));\n      } else {\n        nstack.push(item);\n      }\n    } else if (type === IVAR && Object.hasOwn(values, item.value)) {\n      item = new Instruction(INUMBER, values[item.value]);\n      nstack.push(item);\n    } else if (type === IOP2 && nstack.length > 1) {\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      f = binaryOps[item.value];\n      item = new Instruction(INUMBER, f(n1.value, n2.value));\n      nstack.push(item);\n    } else if (type === IOP3 && nstack.length > 2) {\n      n3 = nstack.pop();\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      if (item.value === '?') {\n        nstack.push(n1.value ? n2.value : n3.value);\n      } else {\n        f = ternaryOps[item.value];\n        item = new Instruction(INUMBER, f(n1.value, n2.value, n3.value));\n        nstack.push(item);\n      }\n    } else if (type === IOP1 && nstack.length > 0) {\n      n1 = nstack.pop();\n      f = unaryOps[item.value];\n      item = new Instruction(INUMBER, f(n1.value));\n      nstack.push(item);\n    } else if (type === IEXPR) {\n      while (nstack.length > 0) {\n        newexpression.push(nstack.shift());\n      }\n      newexpression.push(new Instruction(IEXPR, simplify(item.value, unaryOps, binaryOps, ternaryOps, values)));\n    } else if (type === IMEMBER && nstack.length > 0) {\n      n1 = nstack.pop();\n      nstack.push(new Instruction(INUMBER, n1.value[item.value]));\n    /* } else if (type === IARRAY && nstack.length >= item.value) {\n      var length = item.value;\n      while (length-- > 0) {\n        newexpression.push(nstack.pop());\n      }\n      newexpression.push(new Instruction(IARRAY, item.value));\n    } */\n    } else {\n      while (nstack.length > 0) {\n        newexpression.push(nstack.shift());\n      }\n      newexpression.push(item);\n    }\n  }\n  while (nstack.length > 0) {\n    newexpression.push(nstack.shift());\n  }\n  return newexpression;\n}\n\nfunction substitute(tokens, variable, expr) {\n  var newexpression = [];\n  for (var i = 0; i < tokens.length; i++) {\n    var item = tokens[i];\n    var type = item.type;\n    if (type === IVAR && item.value === variable) {\n      for (var j = 0; j < expr.tokens.length; j++) {\n        var expritem = expr.tokens[j];\n        var replitem;\n        if (expritem.type === IOP1) {\n          replitem = unaryInstruction(expritem.value);\n        } else if (expritem.type === IOP2) {\n          replitem = binaryInstruction(expritem.value);\n        } else if (expritem.type === IOP3) {\n          replitem = ternaryInstruction(expritem.value);\n        } else {\n          replitem = new Instruction(expritem.type, expritem.value);\n        }\n        newexpression.push(replitem);\n      }\n    } else if (type === IEXPR) {\n      newexpression.push(new Instruction(IEXPR, substitute(item.value, variable, expr)));\n    } else {\n      newexpression.push(item);\n    }\n  }\n  return newexpression;\n}\n\n/**\n * Checks if a function reference 'f' is explicitly allowed to be executed.\n * This logic is the core security allowance gate.\n */\nfunction isAllowedFunc(f, expr, values) {\n  for (var key in expr.functions) {\n    if (expr.functions[key] === f) return true;\n  }\n\n  if (f.__expr_eval_safe_def) return true;\n\n  for (var vKey in values) {\n    if (typeof values[vKey] === 'object' && values[vKey] !== null) {\n      for (var subKey in values[vKey]) {\n        if (values[vKey][subKey] === f) return true;\n      }\n    }\n  }\n  return false;\n}\n\nfunction evaluate(tokens, expr, values) {\n  var nstack = [];\n  var n1, n2, n3;\n  var f, args, argCount;\n\n  if (isExpressionEvaluator(tokens)) {\n    return resolveExpression(tokens, values);\n  }\n\n  var numTokens = tokens.length;\n\n  for (var i = 0; i < numTokens; i++) {\n    var item = tokens[i];\n    var type = item.type;\n    if (type === INUMBER || type === IVARNAME) {\n      nstack.push(item.value);\n    } else if (type === IOP2) {\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      if (item.value === 'and') {\n        nstack.push(n1 ? !!evaluate(n2, expr, values) : false);\n      } else if (item.value === 'or') {\n        nstack.push(n1 ? true : !!evaluate(n2, expr, values));\n      } else if (item.value === '=') {\n        f = expr.binaryOps[item.value];\n        nstack.push(f(n1, evaluate(n2, expr, values), values));\n      } else {\n        f = expr.binaryOps[item.value];\n        nstack.push(f(resolveExpression(n1, values), resolveExpression(n2, values)));\n      }\n    } else if (type === IOP3) {\n      n3 = nstack.pop();\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      if (item.value === '?') {\n        nstack.push(evaluate(n1 ? n2 : n3, expr, values));\n      } else {\n        f = expr.ternaryOps[item.value];\n        nstack.push(f(resolveExpression(n1, values), resolveExpression(n2, values), resolveExpression(n3, values)));\n      }\n    } else if (type === IVAR) {\n      if (/^__proto__|prototype|constructor$/.test(item.value)) {\n        throw new Error('prototype access detected');\n      }\n      if (item.value in expr.functions) {\n        nstack.push(expr.functions[item.value]);\n      } else if (item.value in expr.unaryOps && expr.parser.isOperatorEnabled(item.value)) {\n        nstack.push(expr.unaryOps[item.value]);\n      } else {\n        var v = values[item.value];\n\n        if (v !== undefined) {\n          if (typeof v === 'function' && !isAllowedFunc(v, expr, values)) {\n            /* function is not registered, not marked safe, and not a member function. BLOCKED. */\n            throw new Error('Variable references an unallowed function: ' + item.value);\n          }\n          nstack.push(v);\n        } else {\n          throw new Error('undefined variable: ' + item.value);\n        }\n      }\n    } else if (type === IOP1) {\n      n1 = nstack.pop();\n      f = expr.unaryOps[item.value];\n      nstack.push(f(resolveExpression(n1, values)));\n    } else if (type === IFUNCALL) {\n      argCount = item.value;\n      args = [];\n      while (argCount-- > 0) {\n        args.unshift(resolveExpression(nstack.pop(), values));\n      }\n      f = nstack.pop();\n      if (!isAllowedFunc(f, expr, values)) {\n        throw new Error('Is not an allowed function.');\n      }\n      if (f.apply && f.call) {\n        nstack.push(f.apply(undefined, args));\n      } else {\n        throw new Error(f + ' is not a function');\n      }\n    } else if (type === IFUNDEF) {\n      // Create closure to keep references to arguments and expression\n      nstack.push((function () {\n        var n2 = nstack.pop();\n        var args = [];\n        var argCount = item.value;\n        while (argCount-- > 0) {\n          args.unshift(nstack.pop());\n        }\n        var n1 = nstack.pop();\n        var f = function () {\n          var scope = Object.assign({}, values);\n          for (var i = 0, len = args.length; i < len; i++) {\n            scope[args[i]] = arguments[i];\n          }\n          return evaluate(n2, expr, scope);\n        };\n        // f.name = n1\n        Object.defineProperty(f, 'name', {\n          value: n1,\n          writable: false\n        });\n        Object.defineProperty(f, '__expr_eval_safe_def', {\n          value: true,\n          writable: false\n        });\n        values[n1] = f;\n        return f;\n      })());\n    } else if (type === IEXPR) {\n      nstack.push(createExpressionEvaluator(item, expr));\n    } else if (type === IEXPREVAL) {\n      nstack.push(item);\n    } else if (type === IMEMBER) {\n      n1 = nstack.pop();\n      nstack.push(n1[item.value]);\n    } else if (type === IENDSTATEMENT) {\n      nstack.pop();\n    } else if (type === IARRAY) {\n      argCount = item.value;\n      args = [];\n      while (argCount-- > 0) {\n        args.unshift(nstack.pop());\n      }\n      nstack.push(args);\n    } else {\n      throw new Error('invalid Expression');\n    }\n  }\n  if (nstack.length > 1) {\n    throw new Error('invalid Expression (parity)');\n  }\n  // Explicitly return zero to avoid test issues caused by -0\n  return nstack[0] === 0 ? 0 : resolveExpression(nstack[0], values);\n}\n\nfunction createExpressionEvaluator(token, expr, values) {\n  if (isExpressionEvaluator(token)) return token;\n  return {\n    type: IEXPREVAL,\n    value: function (scope) {\n      return evaluate(token.value, expr, scope);\n    }\n  };\n}\n\nfunction isExpressionEvaluator(n) {\n  return n && n.type === IEXPREVAL;\n}\n\nfunction resolveExpression(n, values) {\n  return isExpressionEvaluator(n) ? n.value(values) : n;\n}\n\nfunction expressionToString(tokens, toJS) {\n  var nstack = [];\n  var n1, n2, n3;\n  var f, args, argCount;\n  for (var i = 0; i < tokens.length; i++) {\n    var item = tokens[i];\n    var type = item.type;\n    if (type === INUMBER) {\n      if (typeof item.value === 'number' && item.value < 0) {\n        nstack.push('(' + item.value + ')');\n      } else if (Array.isArray(item.value)) {\n        nstack.push('[' + item.value.map(escapeValue).join(', ') + ']');\n      } else {\n        nstack.push(escapeValue(item.value));\n      }\n    } else if (type === IOP2) {\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      f = item.value;\n      if (toJS) {\n        if (f === '^') {\n          nstack.push('Math.pow(' + n1 + ', ' + n2 + ')');\n        } else if (f === 'and') {\n          nstack.push('(!!' + n1 + ' && !!' + n2 + ')');\n        } else if (f === 'or') {\n          nstack.push('(!!' + n1 + ' || !!' + n2 + ')');\n        } else if (f === '||') {\n          nstack.push('(function(a,b){ return Array.isArray(a) && Array.isArray(b) ? a.concat(b) : String(a) + String(b); }((' + n1 + '),(' + n2 + ')))');\n        } else if (f === '==') {\n          nstack.push('(' + n1 + ' === ' + n2 + ')');\n        } else if (f === '!=') {\n          nstack.push('(' + n1 + ' !== ' + n2 + ')');\n        } else if (f === '[') {\n          nstack.push(n1 + '[(' + n2 + ') | 0]');\n        } else {\n          nstack.push('(' + n1 + ' ' + f + ' ' + n2 + ')');\n        }\n      } else {\n        if (f === '[') {\n          nstack.push(n1 + '[' + n2 + ']');\n        } else {\n          nstack.push('(' + n1 + ' ' + f + ' ' + n2 + ')');\n        }\n      }\n    } else if (type === IOP3) {\n      n3 = nstack.pop();\n      n2 = nstack.pop();\n      n1 = nstack.pop();\n      f = item.value;\n      if (f === '?') {\n        nstack.push('(' + n1 + ' ? ' + n2 + ' : ' + n3 + ')');\n      } else {\n        throw new Error('invalid Expression');\n      }\n    } else if (type === IVAR || type === IVARNAME) {\n      nstack.push(item.value);\n    } else if (type === IOP1) {\n      n1 = nstack.pop();\n      f = item.value;\n      if (f === '-' || f === '+') {\n        nstack.push('(' + f + n1 + ')');\n      } else if (toJS) {\n        if (f === 'not') {\n          nstack.push('(' + '!' + n1 + ')');\n        } else if (f === '!') {\n          nstack.push('fac(' + n1 + ')');\n        } else {\n          nstack.push(f + '(' + n1 + ')');\n        }\n      } else if (f === '!') {\n        nstack.push('(' + n1 + '!)');\n      } else {\n        nstack.push('(' + f + ' ' + n1 + ')');\n      }\n    } else if (type === IFUNCALL) {\n      argCount = item.value;\n      args = [];\n      while (argCount-- > 0) {\n        args.unshift(nstack.pop());\n      }\n      f = nstack.pop();\n      nstack.push(f + '(' + args.join(', ') + ')');\n    } else if (type === IFUNDEF) {\n      n2 = nstack.pop();\n      argCount = item.value;\n      args = [];\n      while (argCount-- > 0) {\n        args.unshift(nstack.pop());\n      }\n      n1 = nstack.pop();\n      if (toJS) {\n        nstack.push('(' + n1 + ' = function(' + args.join(', ') + ') { return ' + n2 + ' })');\n      } else {\n        nstack.push('(' + n1 + '(' + args.join(', ') + ') = ' + n2 + ')');\n      }\n    } else if (type === IMEMBER) {\n      n1 = nstack.pop();\n      nstack.push(n1 + '.' + item.value);\n    } else if (type === IARRAY) {\n      argCount = item.value;\n      args = [];\n      while (argCount-- > 0) {\n        args.unshift(nstack.pop());\n      }\n      nstack.push('[' + args.join(', ') + ']');\n    } else if (type === IEXPR) {\n      nstack.push('(' + expressionToString(item.value, toJS) + ')');\n    } else if (type === IENDSTATEMENT) ; else {\n      throw new Error('invalid Expression');\n    }\n  }\n  if (nstack.length > 1) {\n    if (toJS) {\n      nstack = [nstack.join(',')];\n    } else {\n      nstack = [nstack.join(';')];\n    }\n  }\n  return String(nstack[0]);\n}\n\nfunction escapeValue(v) {\n  if (typeof v === 'string') {\n    return JSON.stringify(v).replace(/\\u2028/g, '\\\\u2028').replace(/\\u2029/g, '\\\\u2029');\n  }\n  return v;\n}\n\nfunction contains(array, obj) {\n  for (var i = 0; i < array.length; i++) {\n    if (array[i] === obj) {\n      return true;\n    }\n  }\n  return false;\n}\n\nfunction getSymbols(tokens, symbols, options) {\n  options = options || {};\n  var withMembers = !!options.withMembers;\n  var prevVar = null;\n\n  for (var i = 0; i < tokens.length; i++) {\n    var item = tokens[i];\n    if (item.type === IVAR || item.type === IVARNAME) {\n      if (!withMembers && !contains(symbols, item.value)) {\n        symbols.push(item.value);\n      } else if (prevVar !== null) {\n        if (!contains(symbols, prevVar)) {\n          symbols.push(prevVar);\n        }\n        prevVar = item.value;\n      } else {\n        prevVar = item.value;\n      }\n    } else if (item.type === IMEMBER && withMembers && prevVar !== null) {\n      prevVar += '.' + item.value;\n    } else if (item.type === IEXPR) {\n      getSymbols(item.value, symbols, options);\n    } else if (prevVar !== null) {\n      if (!contains(symbols, prevVar)) {\n        symbols.push(prevVar);\n      }\n      prevVar = null;\n    }\n  }\n\n  if (prevVar !== null && !contains(symbols, prevVar)) {\n    symbols.push(prevVar);\n  }\n}\n\nfunction Expression(tokens, parser) {\n  this.tokens = tokens;\n  this.parser = parser;\n  this.unaryOps = parser.unaryOps;\n  this.binaryOps = parser.binaryOps;\n  this.ternaryOps = parser.ternaryOps;\n  this.functions = parser.functions;\n}\n\nExpression.prototype.simplify = function (values) {\n  values = values || {};\n  return new Expression(simplify(this.tokens, this.unaryOps, this.binaryOps, this.ternaryOps, values), this.parser);\n};\n\nExpression.prototype.substitute = function (variable, expr) {\n  if (!(expr instanceof Expression)) {\n    expr = this.parser.parse(String(expr));\n  }\n\n  return new Expression(substitute(this.tokens, variable, expr), this.parser);\n};\n\nExpression.prototype.evaluate = function (values) {\n  values = values || {};\n  return evaluate(this.tokens, this, values);\n};\n\nExpression.prototype.toString = function () {\n  return expressionToString(this.tokens, false);\n};\n\nExpression.prototype.symbols = function (options) {\n  options = options || {};\n  var vars = [];\n  getSymbols(this.tokens, vars, options);\n  return vars;\n};\n\nExpression.prototype.variables = function (options) {\n  options = options || {};\n  var vars = [];\n  getSymbols(this.tokens, vars, options);\n  var functions = this.functions;\n  return vars.filter(function (name) {\n    return !(name in functions);\n  });\n};\n\nExpression.prototype.toJSFunction = function (param, variables) {\n  var expr = this;\n  var f = new Function(param, 'with(this.functions) with (this.ternaryOps) with (this.binaryOps) with (this.unaryOps) { return ' + expressionToString(this.simplify(variables).tokens, true) + '; }'); // eslint-disable-line no-new-func\n  return function () {\n    return f.apply(expr, arguments);\n  };\n};\n\nvar TEOF = 'TEOF';\nvar TOP = 'TOP';\nvar TNUMBER = 'TNUMBER';\nvar TSTRING = 'TSTRING';\nvar TPAREN = 'TPAREN';\nvar TBRACKET = 'TBRACKET';\nvar TCOMMA = 'TCOMMA';\nvar TNAME = 'TNAME';\nvar TSEMICOLON = 'TSEMICOLON';\n\nfunction Token(type, value, index) {\n  this.type = type;\n  this.value = value;\n  this.index = index;\n}\n\nToken.prototype.toString = function () {\n  return this.type + ': ' + this.value;\n};\n\nfunction TokenStream(parser, expression) {\n  this.pos = 0;\n  this.current = null;\n  this.unaryOps = parser.unaryOps;\n  this.binaryOps = parser.binaryOps;\n  this.ternaryOps = parser.ternaryOps;\n  this.consts = parser.consts;\n  this.expression = expression;\n  this.savedPosition = 0;\n  this.savedCurrent = null;\n  this.options = parser.options;\n  this.parser = parser;\n}\n\nTokenStream.prototype.newToken = function (type, value, pos) {\n  return new Token(type, value, pos != null ? pos : this.pos);\n};\n\nTokenStream.prototype.save = function () {\n  this.savedPosition = this.pos;\n  this.savedCurrent = this.current;\n};\n\nTokenStream.prototype.restore = function () {\n  this.pos = this.savedPosition;\n  this.current = this.savedCurrent;\n};\n\nTokenStream.prototype.next = function () {\n  if (this.pos >= this.expression.length) {\n    return this.newToken(TEOF, 'EOF');\n  }\n\n  if (this.isWhitespace() || this.isComment()) {\n    return this.next();\n  } else if (this.isRadixInteger() ||\n      this.isNumber() ||\n      this.isOperator() ||\n      this.isString() ||\n      this.isParen() ||\n      this.isBracket() ||\n      this.isComma() ||\n      this.isSemicolon() ||\n      this.isNamedOp() ||\n      this.isConst() ||\n      this.isName()) {\n    return this.current;\n  } else {\n    this.parseError('Unknown character \"' + this.expression.charAt(this.pos) + '\"');\n  }\n};\n\nTokenStream.prototype.isString = function () {\n  var r = false;\n  var startPos = this.pos;\n  var quote = this.expression.charAt(startPos);\n\n  if (quote === '\\'' || quote === '\"') {\n    var index = this.expression.indexOf(quote, startPos + 1);\n    while (index >= 0 && this.pos < this.expression.length) {\n      this.pos = index + 1;\n      if (this.expression.charAt(index - 1) !== '\\\\') {\n        var rawString = this.expression.substring(startPos + 1, index);\n        this.current = this.newToken(TSTRING, this.unescape(rawString), startPos);\n        r = true;\n        break;\n      }\n      index = this.expression.indexOf(quote, index + 1);\n    }\n  }\n  return r;\n};\n\nTokenStream.prototype.isParen = function () {\n  var c = this.expression.charAt(this.pos);\n  if (c === '(' || c === ')') {\n    this.current = this.newToken(TPAREN, c);\n    this.pos++;\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isBracket = function () {\n  var c = this.expression.charAt(this.pos);\n  if ((c === '[' || c === ']') && this.isOperatorEnabled('[')) {\n    this.current = this.newToken(TBRACKET, c);\n    this.pos++;\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isComma = function () {\n  var c = this.expression.charAt(this.pos);\n  if (c === ',') {\n    this.current = this.newToken(TCOMMA, ',');\n    this.pos++;\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isSemicolon = function () {\n  var c = this.expression.charAt(this.pos);\n  if (c === ';') {\n    this.current = this.newToken(TSEMICOLON, ';');\n    this.pos++;\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isConst = function () {\n  var startPos = this.pos;\n  var i = startPos;\n  for (; i < this.expression.length; i++) {\n    var c = this.expression.charAt(i);\n    if (c.toUpperCase() === c.toLowerCase()) {\n      if (i === this.pos || (c !== '_' && c !== '.' && (c < '0' || c > '9'))) {\n        break;\n      }\n    }\n  }\n  if (i > startPos) {\n    var str = this.expression.substring(startPos, i);\n    if (str in this.consts) {\n      this.current = this.newToken(TNUMBER, this.consts[str]);\n      this.pos += str.length;\n      return true;\n    }\n  }\n  return false;\n};\n\nTokenStream.prototype.isNamedOp = function () {\n  var startPos = this.pos;\n  var i = startPos;\n  for (; i < this.expression.length; i++) {\n    var c = this.expression.charAt(i);\n    if (c.toUpperCase() === c.toLowerCase()) {\n      if (i === this.pos || (c !== '_' && (c < '0' || c > '9'))) {\n        break;\n      }\n    }\n  }\n  if (i > startPos) {\n    var str = this.expression.substring(startPos, i);\n    if (this.isOperatorEnabled(str) && (str in this.binaryOps || str in this.unaryOps || str in this.ternaryOps)) {\n      this.current = this.newToken(TOP, str);\n      this.pos += str.length;\n      return true;\n    }\n  }\n  return false;\n};\n\nTokenStream.prototype.isName = function () {\n  var startPos = this.pos;\n  var i = startPos;\n  var hasLetter = false;\n  for (; i < this.expression.length; i++) {\n    var c = this.expression.charAt(i);\n    if (c.toUpperCase() === c.toLowerCase()) {\n      if (i === this.pos && (c === '$' || c === '_')) {\n        if (c === '_') {\n          hasLetter = true;\n        }\n        continue;\n      } else if (i === this.pos || !hasLetter || (c !== '_' && (c < '0' || c > '9'))) {\n        break;\n      }\n    } else {\n      hasLetter = true;\n    }\n  }\n  if (hasLetter) {\n    var str = this.expression.substring(startPos, i);\n    this.current = this.newToken(TNAME, str);\n    this.pos += str.length;\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isWhitespace = function () {\n  var r = false;\n  var c = this.expression.charAt(this.pos);\n  while (c === ' ' || c === '\\t' || c === '\\n' || c === '\\r') {\n    r = true;\n    this.pos++;\n    if (this.pos >= this.expression.length) {\n      break;\n    }\n    c = this.expression.charAt(this.pos);\n  }\n  return r;\n};\n\nvar codePointPattern = /^[0-9a-f]{4}$/i;\n\nTokenStream.prototype.unescape = function (v) {\n  var index = v.indexOf('\\\\');\n  if (index < 0) {\n    return v;\n  }\n\n  var buffer = v.substring(0, index);\n  while (index >= 0) {\n    var c = v.charAt(++index);\n    switch (c) {\n      case '\\'':\n        buffer += '\\'';\n        break;\n      case '\"':\n        buffer += '\"';\n        break;\n      case '\\\\':\n        buffer += '\\\\';\n        break;\n      case '/':\n        buffer += '/';\n        break;\n      case 'b':\n        buffer += '\\b';\n        break;\n      case 'f':\n        buffer += '\\f';\n        break;\n      case 'n':\n        buffer += '\\n';\n        break;\n      case 'r':\n        buffer += '\\r';\n        break;\n      case 't':\n        buffer += '\\t';\n        break;\n      case 'u':\n        // interpret the following 4 characters as the hex of the unicode code point\n        var codePoint = v.substring(index + 1, index + 5);\n        if (!codePointPattern.test(codePoint)) {\n          this.parseError('Illegal escape sequence: \\\\u' + codePoint);\n        }\n        buffer += String.fromCharCode(parseInt(codePoint, 16));\n        index += 4;\n        break;\n      default:\n        throw this.parseError('Illegal escape sequence: \"\\\\' + c + '\"');\n    }\n    ++index;\n    var backslash = v.indexOf('\\\\', index);\n    buffer += v.substring(index, backslash < 0 ? v.length : backslash);\n    index = backslash;\n  }\n\n  return buffer;\n};\n\nTokenStream.prototype.isComment = function () {\n  var c = this.expression.charAt(this.pos);\n  if (c === '/' && this.expression.charAt(this.pos + 1) === '*') {\n    this.pos = this.expression.indexOf('*/', this.pos) + 2;\n    if (this.pos === 1) {\n      this.pos = this.expression.length;\n    }\n    return true;\n  }\n  return false;\n};\n\nTokenStream.prototype.isRadixInteger = function () {\n  var pos = this.pos;\n\n  if (pos >= this.expression.length - 2 || this.expression.charAt(pos) !== '0') {\n    return false;\n  }\n  ++pos;\n\n  var radix;\n  var validDigit;\n  if (this.expression.charAt(pos) === 'x') {\n    radix = 16;\n    validDigit = /^[0-9a-f]$/i;\n    ++pos;\n  } else if (this.expression.charAt(pos) === 'b') {\n    radix = 2;\n    validDigit = /^[01]$/i;\n    ++pos;\n  } else {\n    return false;\n  }\n\n  var valid = false;\n  var startPos = pos;\n\n  while (pos < this.expression.length) {\n    var c = this.expression.charAt(pos);\n    if (validDigit.test(c)) {\n      pos++;\n      valid = true;\n    } else {\n      break;\n    }\n  }\n\n  if (valid) {\n    this.current = this.newToken(TNUMBER, parseInt(this.expression.substring(startPos, pos), radix));\n    this.pos = pos;\n  }\n  return valid;\n};\n\nTokenStream.prototype.isNumber = function () {\n  var valid = false;\n  var pos = this.pos;\n  var startPos = pos;\n  var resetPos = pos;\n  var foundDot = false;\n  var foundDigits = false;\n  var c;\n\n  while (pos < this.expression.length) {\n    c = this.expression.charAt(pos);\n    if ((c >= '0' && c <= '9') || (!foundDot && c === '.')) {\n      if (c === '.') {\n        foundDot = true;\n      } else {\n        foundDigits = true;\n      }\n      pos++;\n      valid = foundDigits;\n    } else {\n      break;\n    }\n  }\n\n  if (valid) {\n    resetPos = pos;\n  }\n\n  if (c === 'e' || c === 'E') {\n    pos++;\n    var acceptSign = true;\n    var validExponent = false;\n    while (pos < this.expression.length) {\n      c = this.expression.charAt(pos);\n      if (acceptSign && (c === '+' || c === '-')) {\n        acceptSign = false;\n      } else if (c >= '0' && c <= '9') {\n        validExponent = true;\n        acceptSign = false;\n      } else {\n        break;\n      }\n      pos++;\n    }\n\n    if (!validExponent) {\n      pos = resetPos;\n    }\n  }\n\n  if (valid) {\n    this.current = this.newToken(TNUMBER, parseFloat(this.expression.substring(startPos, pos)));\n    this.pos = pos;\n  } else {\n    this.pos = resetPos;\n  }\n  return valid;\n};\n\nTokenStream.prototype.isOperator = function () {\n  var startPos = this.pos;\n  var c = this.expression.charAt(this.pos);\n\n  if (c === '+' || c === '-' || c === '*' || c === '/' || c === '%' || c === '^' || c === '?' || c === ':' || c === '.') {\n    this.current = this.newToken(TOP, c);\n  } else if (c === '∙' || c === '•') {\n    this.current = this.newToken(TOP, '*');\n  } else if (c === '>') {\n    if (this.expression.charAt(this.pos + 1) === '=') {\n      this.current = this.newToken(TOP, '>=');\n      this.pos++;\n    } else {\n      this.current = this.newToken(TOP, '>');\n    }\n  } else if (c === '<') {\n    if (this.expression.charAt(this.pos + 1) === '=') {\n      this.current = this.newToken(TOP, '<=');\n      this.pos++;\n    } else {\n      this.current = this.newToken(TOP, '<');\n    }\n  } else if (c === '|') {\n    if (this.expression.charAt(this.pos + 1) === '|') {\n      this.current = this.newToken(TOP, '||');\n      this.pos++;\n    } else {\n      return false;\n    }\n  } else if (c === '=') {\n    if (this.expression.charAt(this.pos + 1) === '=') {\n      this.current = this.newToken(TOP, '==');\n      this.pos++;\n    } else {\n      this.current = this.newToken(TOP, c);\n    }\n  } else if (c === '!') {\n    if (this.expression.charAt(this.pos + 1) === '=') {\n      this.current = this.newToken(TOP, '!=');\n      this.pos++;\n    } else {\n      this.current = this.newToken(TOP, c);\n    }\n  } else {\n    return false;\n  }\n  this.pos++;\n\n  if (this.isOperatorEnabled(this.current.value)) {\n    return true;\n  } else {\n    this.pos = startPos;\n    return false;\n  }\n};\n\nTokenStream.prototype.isOperatorEnabled = function (op) {\n  return this.parser.isOperatorEnabled(op);\n};\n\nTokenStream.prototype.getCoordinates = function () {\n  var line = 0;\n  var column;\n  var newline = -1;\n  do {\n    line++;\n    column = this.pos - newline;\n    newline = this.expression.indexOf('\\n', newline + 1);\n  } while (newline >= 0 && newline < this.pos);\n\n  return {\n    line: line,\n    column: column\n  };\n};\n\nTokenStream.prototype.parseError = function (msg) {\n  var coords = this.getCoordinates();\n  throw new Error('parse error [' + coords.line + ':' + coords.column + ']: ' + msg);\n};\n\nfunction ParserState(parser, tokenStream, options) {\n  this.parser = parser;\n  this.tokens = tokenStream;\n  this.current = null;\n  this.nextToken = null;\n  this.next();\n  this.savedCurrent = null;\n  this.savedNextToken = null;\n  this.allowMemberAccess = options.allowMemberAccess !== false;\n}\n\nParserState.prototype.next = function () {\n  this.current = this.nextToken;\n  return (this.nextToken = this.tokens.next());\n};\n\nParserState.prototype.tokenMatches = function (token, value) {\n  if (typeof value === 'undefined') {\n    return true;\n  } else if (Array.isArray(value)) {\n    return contains(value, token.value);\n  } else if (typeof value === 'function') {\n    return value(token);\n  } else {\n    return token.value === value;\n  }\n};\n\nParserState.prototype.save = function () {\n  this.savedCurrent = this.current;\n  this.savedNextToken = this.nextToken;\n  this.tokens.save();\n};\n\nParserState.prototype.restore = function () {\n  this.tokens.restore();\n  this.current = this.savedCurrent;\n  this.nextToken = this.savedNextToken;\n};\n\nParserState.prototype.accept = function (type, value) {\n  if (this.nextToken.type === type && this.tokenMatches(this.nextToken, value)) {\n    this.next();\n    return true;\n  }\n  return false;\n};\n\nParserState.prototype.expect = function (type, value) {\n  if (!this.accept(type, value)) {\n    var coords = this.tokens.getCoordinates();\n    throw new Error('parse error [' + coords.line + ':' + coords.column + ']: Expected ' + (value || type));\n  }\n};\n\nParserState.prototype.parseAtom = function (instr) {\n  var unaryOps = this.tokens.unaryOps;\n  function isPrefixOperator(token) {\n    return token.value in unaryOps;\n  }\n\n  if (this.accept(TNAME) || this.accept(TOP, isPrefixOperator)) {\n    instr.push(new Instruction(IVAR, this.current.value));\n  } else if (this.accept(TNUMBER)) {\n    instr.push(new Instruction(INUMBER, this.current.value));\n  } else if (this.accept(TSTRING)) {\n    instr.push(new Instruction(INUMBER, this.current.value));\n  } else if (this.accept(TPAREN, '(')) {\n    this.parseExpression(instr);\n    this.expect(TPAREN, ')');\n  } else if (this.accept(TBRACKET, '[')) {\n    if (this.accept(TBRACKET, ']')) {\n      instr.push(new Instruction(IARRAY, 0));\n    } else {\n      var argCount = this.parseArrayList(instr);\n      instr.push(new Instruction(IARRAY, argCount));\n    }\n  } else {\n    throw new Error('unexpected ' + this.nextToken);\n  }\n};\n\nParserState.prototype.parseExpression = function (instr) {\n  var exprInstr = [];\n  if (this.parseUntilEndStatement(instr, exprInstr)) {\n    return;\n  }\n  this.parseVariableAssignmentExpression(exprInstr);\n  if (this.parseUntilEndStatement(instr, exprInstr)) {\n    return;\n  }\n  this.pushExpression(instr, exprInstr);\n};\n\nParserState.prototype.pushExpression = function (instr, exprInstr) {\n  for (var i = 0, len = exprInstr.length; i < len; i++) {\n    instr.push(exprInstr[i]);\n  }\n};\n\nParserState.prototype.parseUntilEndStatement = function (instr, exprInstr) {\n  if (!this.accept(TSEMICOLON)) return false;\n  if (this.nextToken && this.nextToken.type !== TEOF && !(this.nextToken.type === TPAREN && this.nextToken.value === ')')) {\n    exprInstr.push(new Instruction(IENDSTATEMENT));\n  }\n  if (this.nextToken.type !== TEOF) {\n    this.parseExpression(exprInstr);\n  }\n  instr.push(new Instruction(IEXPR, exprInstr));\n  return true;\n};\n\nParserState.prototype.parseArrayList = function (instr) {\n  var argCount = 0;\n\n  while (!this.accept(TBRACKET, ']')) {\n    this.parseExpression(instr);\n    ++argCount;\n    while (this.accept(TCOMMA)) {\n      this.parseExpression(instr);\n      ++argCount;\n    }\n  }\n\n  return argCount;\n};\n\nParserState.prototype.parseVariableAssignmentExpression = function (instr) {\n  this.parseConditionalExpression(instr);\n  while (this.accept(TOP, '=')) {\n    var varName = instr.pop();\n    var varValue = [];\n    var lastInstrIndex = instr.length - 1;\n    if (varName.type === IFUNCALL) {\n      if (!this.tokens.isOperatorEnabled('()=')) {\n        throw new Error('function definition is not permitted');\n      }\n      for (var i = 0, len = varName.value + 1; i < len; i++) {\n        var index = lastInstrIndex - i;\n        if (instr[index].type === IVAR) {\n          instr[index] = new Instruction(IVARNAME, instr[index].value);\n        }\n      }\n      this.parseVariableAssignmentExpression(varValue);\n      instr.push(new Instruction(IEXPR, varValue));\n      instr.push(new Instruction(IFUNDEF, varName.value));\n      continue;\n    }\n    if (varName.type !== IVAR && varName.type !== IMEMBER) {\n      throw new Error('expected variable for assignment');\n    }\n    this.parseVariableAssignmentExpression(varValue);\n    instr.push(new Instruction(IVARNAME, varName.value));\n    instr.push(new Instruction(IEXPR, varValue));\n    instr.push(binaryInstruction('='));\n  }\n};\n\nParserState.prototype.parseConditionalExpression = function (instr) {\n  this.parseOrExpression(instr);\n  while (this.accept(TOP, '?')) {\n    var trueBranch = [];\n    var falseBranch = [];\n    this.parseConditionalExpression(trueBranch);\n    this.expect(TOP, ':');\n    this.parseConditionalExpression(falseBranch);\n    instr.push(new Instruction(IEXPR, trueBranch));\n    instr.push(new Instruction(IEXPR, falseBranch));\n    instr.push(ternaryInstruction('?'));\n  }\n};\n\nParserState.prototype.parseOrExpression = function (instr) {\n  this.parseAndExpression(instr);\n  while (this.accept(TOP, 'or')) {\n    var falseBranch = [];\n    this.parseAndExpression(falseBranch);\n    instr.push(new Instruction(IEXPR, falseBranch));\n    instr.push(binaryInstruction('or'));\n  }\n};\n\nParserState.prototype.parseAndExpression = function (instr) {\n  this.parseComparison(instr);\n  while (this.accept(TOP, 'and')) {\n    var trueBranch = [];\n    this.parseComparison(trueBranch);\n    instr.push(new Instruction(IEXPR, trueBranch));\n    instr.push(binaryInstruction('and'));\n  }\n};\n\nvar COMPARISON_OPERATORS = ['==', '!=', '<', '<=', '>=', '>', 'in'];\n\nParserState.prototype.parseComparison = function (instr) {\n  this.parseAddSub(instr);\n  while (this.accept(TOP, COMPARISON_OPERATORS)) {\n    var op = this.current;\n    this.parseAddSub(instr);\n    instr.push(binaryInstruction(op.value));\n  }\n};\n\nvar ADD_SUB_OPERATORS = ['+', '-', '||'];\n\nParserState.prototype.parseAddSub = function (instr) {\n  this.parseTerm(instr);\n  while (this.accept(TOP, ADD_SUB_OPERATORS)) {\n    var op = this.current;\n    this.parseTerm(instr);\n    instr.push(binaryInstruction(op.value));\n  }\n};\n\nvar TERM_OPERATORS = ['*', '/', '%'];\n\nParserState.prototype.parseTerm = function (instr) {\n  this.parseFactor(instr);\n  while (this.accept(TOP, TERM_OPERATORS)) {\n    var op = this.current;\n    this.parseFactor(instr);\n    instr.push(binaryInstruction(op.value));\n  }\n};\n\nParserState.prototype.parseFactor = function (instr) {\n  var unaryOps = this.tokens.unaryOps;\n  function isPrefixOperator(token) {\n    return token.value in unaryOps;\n  }\n\n  this.save();\n  if (this.accept(TOP, isPrefixOperator)) {\n    if (this.current.value !== '-' && this.current.value !== '+') {\n      if (this.nextToken.type === TPAREN && this.nextToken.value === '(') {\n        this.restore();\n        this.parseExponential(instr);\n        return;\n      } else if (this.nextToken.type === TSEMICOLON || this.nextToken.type === TCOMMA || this.nextToken.type === TEOF || (this.nextToken.type === TPAREN && this.nextToken.value === ')')) {\n        this.restore();\n        this.parseAtom(instr);\n        return;\n      }\n    }\n\n    var op = this.current;\n    this.parseFactor(instr);\n    instr.push(unaryInstruction(op.value));\n  } else {\n    this.parseExponential(instr);\n  }\n};\n\nParserState.prototype.parseExponential = function (instr) {\n  this.parsePostfixExpression(instr);\n  while (this.accept(TOP, '^')) {\n    this.parseFactor(instr);\n    instr.push(binaryInstruction('^'));\n  }\n};\n\nParserState.prototype.parsePostfixExpression = function (instr) {\n  this.parseFunctionCall(instr);\n  while (this.accept(TOP, '!')) {\n    instr.push(unaryInstruction('!'));\n  }\n};\n\nParserState.prototype.parseFunctionCall = function (instr) {\n  var unaryOps = this.tokens.unaryOps;\n  function isPrefixOperator(token) {\n    return token.value in unaryOps;\n  }\n\n  if (this.accept(TOP, isPrefixOperator)) {\n    var op = this.current;\n    this.parseAtom(instr);\n    instr.push(unaryInstruction(op.value));\n  } else {\n    this.parseMemberExpression(instr);\n    while (this.accept(TPAREN, '(')) {\n      if (this.accept(TPAREN, ')')) {\n        instr.push(new Instruction(IFUNCALL, 0));\n      } else {\n        var argCount = this.parseArgumentList(instr);\n        instr.push(new Instruction(IFUNCALL, argCount));\n      }\n    }\n  }\n};\n\nParserState.prototype.parseArgumentList = function (instr) {\n  var argCount = 0;\n\n  while (!this.accept(TPAREN, ')')) {\n    this.parseExpression(instr);\n    ++argCount;\n    while (this.accept(TCOMMA)) {\n      this.parseExpression(instr);\n      ++argCount;\n    }\n  }\n\n  return argCount;\n};\n\nParserState.prototype.parseMemberExpression = function (instr) {\n  this.parseAtom(instr);\n  while (this.accept(TOP, '.') || this.accept(TBRACKET, '[')) {\n    var op = this.current;\n\n    if (op.value === '.') {\n      if (!this.allowMemberAccess) {\n        throw new Error('unexpected \".\", member access is not permitted');\n      }\n\n      this.expect(TNAME);\n      instr.push(new Instruction(IMEMBER, this.current.value));\n    } else if (op.value === '[') {\n      if (!this.tokens.isOperatorEnabled('[')) {\n        throw new Error('unexpected \"[]\", arrays are disabled');\n      }\n\n      this.parseExpression(instr);\n      this.expect(TBRACKET, ']');\n      instr.push(binaryInstruction('['));\n    } else {\n      throw new Error('unexpected symbol: ' + op.value);\n    }\n  }\n};\n\nfunction add(a, b) {\n  return Number(a) + Number(b);\n}\n\nfunction sub(a, b) {\n  return a - b;\n}\n\nfunction mul(a, b) {\n  return a * b;\n}\n\nfunction div(a, b) {\n  return a / b;\n}\n\nfunction mod(a, b) {\n  return a % b;\n}\n\nfunction concat(a, b) {\n  if (Array.isArray(a) && Array.isArray(b)) {\n    return a.concat(b);\n  }\n  return '' + a + b;\n}\n\nfunction equal(a, b) {\n  return a === b;\n}\n\nfunction notEqual(a, b) {\n  return a !== b;\n}\n\nfunction greaterThan(a, b) {\n  return a > b;\n}\n\nfunction lessThan(a, b) {\n  return a < b;\n}\n\nfunction greaterThanEqual(a, b) {\n  return a >= b;\n}\n\nfunction lessThanEqual(a, b) {\n  return a <= b;\n}\n\nfunction andOperator(a, b) {\n  return Boolean(a && b);\n}\n\nfunction orOperator(a, b) {\n  return Boolean(a || b);\n}\n\nfunction inOperator(a, b) {\n  return contains(b, a);\n}\n\nfunction sinh(a) {\n  return ((Math.exp(a) - Math.exp(-a)) / 2);\n}\n\nfunction cosh(a) {\n  return ((Math.exp(a) + Math.exp(-a)) / 2);\n}\n\nfunction tanh(a) {\n  if (a === Infinity) return 1;\n  if (a === -Infinity) return -1;\n  return (Math.exp(a) - Math.exp(-a)) / (Math.exp(a) + Math.exp(-a));\n}\n\nfunction asinh(a) {\n  if (a === -Infinity) return a;\n  return Math.log(a + Math.sqrt((a * a) + 1));\n}\n\nfunction acosh(a) {\n  return Math.log(a + Math.sqrt((a * a) - 1));\n}\n\nfunction atanh(a) {\n  return (Math.log((1 + a) / (1 - a)) / 2);\n}\n\nfunction log10(a) {\n  return Math.log(a) * Math.LOG10E;\n}\n\nfunction neg(a) {\n  return -a;\n}\n\nfunction not(a) {\n  return !a;\n}\n\nfunction trunc(a) {\n  return a < 0 ? Math.ceil(a) : Math.floor(a);\n}\n\nfunction random(a) {\n  return Math.random() * (a || 1);\n}\n\nfunction factorial(a) { // a!\n  return gamma(a + 1);\n}\n\nfunction isInteger(value) {\n  return isFinite(value) && (value === Math.round(value));\n}\n\nvar GAMMA_G = 4.7421875;\nvar GAMMA_P = [\n  0.99999999999999709182,\n  57.156235665862923517, -59.597960355475491248,\n  14.136097974741747174, -0.49191381609762019978,\n  0.33994649984811888699e-4,\n  0.46523628927048575665e-4, -0.98374475304879564677e-4,\n  0.15808870322491248884e-3, -0.21026444172410488319e-3,\n  0.21743961811521264320e-3, -0.16431810653676389022e-3,\n  0.84418223983852743293e-4, -0.26190838401581408670e-4,\n  0.36899182659531622704e-5\n];\n\n// Gamma function from math.js\nfunction gamma(n) {\n  var t, x;\n\n  if (isInteger(n)) {\n    if (n <= 0) {\n      return isFinite(n) ? Infinity : NaN;\n    }\n\n    if (n > 171) {\n      return Infinity; // Will overflow\n    }\n\n    var value = n - 2;\n    var res = n - 1;\n    while (value > 1) {\n      res *= value;\n      value--;\n    }\n\n    if (res === 0) {\n      res = 1; // 0! is per definition 1\n    }\n\n    return res;\n  }\n\n  if (n < 0.5) {\n    return Math.PI / (Math.sin(Math.PI * n) * gamma(1 - n));\n  }\n\n  if (n >= 171.35) {\n    return Infinity; // will overflow\n  }\n\n  if (n > 85.0) { // Extended Stirling Approx\n    var twoN = n * n;\n    var threeN = twoN * n;\n    var fourN = threeN * n;\n    var fiveN = fourN * n;\n    return Math.sqrt(2 * Math.PI / n) * Math.pow((n / Math.E), n) *\n      (1 + (1 / (12 * n)) + (1 / (288 * twoN)) - (139 / (51840 * threeN)) -\n      (571 / (2488320 * fourN)) + (163879 / (209018880 * fiveN)) +\n      (5246819 / (75246796800 * fiveN * n)));\n  }\n\n  --n;\n  x = GAMMA_P[0];\n  for (var i = 1; i < GAMMA_P.length; ++i) {\n    x += GAMMA_P[i] / (n + i);\n  }\n\n  t = n + GAMMA_G + 0.5;\n  return Math.sqrt(2 * Math.PI) * Math.pow(t, n + 0.5) * Math.exp(-t) * x;\n}\n\nfunction stringOrArrayLength(s) {\n  if (Array.isArray(s)) {\n    return s.length;\n  }\n  return String(s).length;\n}\n\nfunction hypot() {\n  var sum = 0;\n  var larg = 0;\n  for (var i = 0; i < arguments.length; i++) {\n    var arg = Math.abs(arguments[i]);\n    var div;\n    if (larg < arg) {\n      div = larg / arg;\n      sum = (sum * div * div) + 1;\n      larg = arg;\n    } else if (arg > 0) {\n      div = arg / larg;\n      sum += div * div;\n    } else {\n      sum += arg;\n    }\n  }\n  return larg === Infinity ? Infinity : larg * Math.sqrt(sum);\n}\n\nfunction condition(cond, yep, nope) {\n  return cond ? yep : nope;\n}\n\n/**\n* Decimal adjustment of a number.\n* From @escopecz.\n*\n* @param {Number} value The number.\n* @param {Integer} exp  The exponent (the 10 logarithm of the adjustment base).\n* @return {Number} The adjusted value.\n*/\nfunction roundTo(value, exp) {\n  // If the exp is undefined or zero...\n  if (typeof exp === 'undefined' || +exp === 0) {\n    return Math.round(value);\n  }\n  value = +value;\n  exp = -(+exp);\n  // If the value is not a number or the exp is not an integer...\n  if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) {\n    return NaN;\n  }\n  // Shift\n  value = value.toString().split('e');\n  value = Math.round(+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp)));\n  // Shift back\n  value = value.toString().split('e');\n  return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp));\n}\n\nfunction setVar(name, value, variables) {\n  if (variables) variables[name] = value;\n  return value;\n}\n\nfunction arrayIndex(array, index) {\n  return array[index | 0];\n}\n\nfunction max(array) {\n  if (arguments.length === 1 && Array.isArray(array)) {\n    return Math.max.apply(Math, array);\n  } else {\n    return Math.max.apply(Math, arguments);\n  }\n}\n\nfunction min(array) {\n  if (arguments.length === 1 && Array.isArray(array)) {\n    return Math.min.apply(Math, array);\n  } else {\n    return Math.min.apply(Math, arguments);\n  }\n}\n\nfunction arrayMap(f, a) {\n  if (typeof f !== 'function') {\n    throw new Error('First argument to map is not a function');\n  }\n  if (!Array.isArray(a)) {\n    throw new Error('Second argument to map is not an array');\n  }\n  return a.map(function (x, i) {\n    return f(x, i);\n  });\n}\n\nfunction arrayFold(f, init, a) {\n  if (typeof f !== 'function') {\n    throw new Error('First argument to fold is not a function');\n  }\n  if (!Array.isArray(a)) {\n    throw new Error('Second argument to fold is not an array');\n  }\n  return a.reduce(function (acc, x, i) {\n    return f(acc, x, i);\n  }, init);\n}\n\nfunction arrayFilter(f, a) {\n  if (typeof f !== 'function') {\n    throw new Error('First argument to filter is not a function');\n  }\n  if (!Array.isArray(a)) {\n    throw new Error('Second argument to filter is not an array');\n  }\n  return a.filter(function (x, i) {\n    return f(x, i);\n  });\n}\n\nfunction stringOrArrayIndexOf(target, s) {\n  if (!(Array.isArray(s) || typeof s === 'string')) {\n    throw n