numenor/lib/Parser/index.js

Customizable, safe evaluator of JavaScript-like expressions.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.ExpressionType = exports.ParserError = exports.Precedence = exports.Parselet = exports.Expression = exports.Parser = void 0;

var _Lexer = require("../Lexer");

var Expression = _interopRequireWildcard(require("./Expression"));

exports.Expression = Expression;

var Parselet = _interopRequireWildcard(require("./Parselet"));

exports.Parselet = Parselet;

var Precedence = _interopRequireWildcard(require("./Precedence"));

exports.Precedence = Precedence;

var Error = _interopRequireWildcard(require("./Error"));

exports.ParserError = Error;

var ExpressionType = _interopRequireWildcard(require("./ExpressionType"));

exports.ExpressionType = ExpressionType;

var _EventEmitter2 = require("../common/EventEmitter");

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) { var desc = Object.defineProperty && Object.getOwnPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : {}; if (desc.get || desc.set) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } } newObj.default = obj; return newObj; } }

function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }

function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }

function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }

function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }

function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

var ParserContext =
/*#__PURE__*/
function () {
  function ParserContext(fireEvent, lexer, prefix, infix) {
    var ignored = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : new Set();
    var context = arguments.length > 5 ? arguments[5] : undefined;

    _classCallCheck(this, ParserContext);

    this.fireEvent = fireEvent;
    this.lexer = lexer;
    this.prefix = prefix;
    this.infix = infix;
    this.ignored = ignored;
    this.context = context;

    _defineProperty(this, "queue", []);

    _defineProperty(this, "scopeStack", []);

    this.skipIgnored();
  }

  _createClass(ParserContext, [{
    key: "parse",
    value: function parse() {
      var precedence = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;
      var token = this.shift();
      var parser = this.getPrefix(token);

      if (parser === undefined) {
        throw new SyntaxError(Error.UnknownToken(token));
      }

      this.scopeStack.push(token.type);
      this.fireEvent('scope:enter', token.type, this.scopeStack);
      var expression = parser(this, token, this.context);
      this.fireEvent('scope:leave', this.scopeStack.pop(), this.scopeStack);
      this.fireEvent('node', {
        get node() {
          return expression;
        },

        replaceWith: function replaceWith(expr) {
          expression = expr;
        }
      });

      while (true) {
        var _parser = this.getInfix(this.token);

        if (_parser === undefined || precedence >= _parser.precedence) {
          break;
        }

        expression = _parser(this, expression, this.shift(), this.context);
      }

      return expression;
    }
  }, {
    key: "match",
    value: function match(tokenType) {
      return this.token.type === tokenType;
    }
  }, {
    key: "accept",
    value: function accept(tokenType) {
      if (!this.match(tokenType)) {
        return false;
      }

      this.shift();
      return true;
    }
  }, {
    key: "peek",
    value: function peek() {
      var offset = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;

      while (this.queue.length <= offset) {
        var token = this.lexer.shift();

        if (token.type === _Lexer.TokenType.EOF) {
          return token;
        }

        if (!this.ignored.has(token.type)) {
          this.queue.push(token);
        }
      }

      return this.queue[offset];
    }
  }, {
    key: "shift",
    value: function shift() {
      var token;

      do {
        if (this.queue.length > 0) {
          token = this.queue.shift();
        } else {
          token = this.lexer.shift();
        }
      } while (this.ignored.has(token.type));

      return token;
    }
  }, {
    key: "unshift",
    value: function unshift(token) {
      this.queue.unshift(token);
    }
  }, {
    key: "expect",
    value: function expect(tokenType) {
      if (this.token.type !== tokenType) {
        throw new SyntaxError(Error.UnexpectedToken(tokenType, this.token));
      }

      return this.shift();
    }
  }, {
    key: "skipIgnored",
    value: function skipIgnored() {
      while (this.ignored.has(this.lexer.token.type)) {
        this.lexer.next();
      }
    }
  }, {
    key: "getParser",
    value: function getParser(registry, token) {
      var parsers = registry.get(token.type);

      if (parsers) {
        var _iteratorNormalCompletion = true;
        var _didIteratorError = false;
        var _iteratorError = undefined;

        try {
          for (var _iterator = parsers[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
            var parser = _step.value;

            if (!parser.matches || parser.matches(this, token)) {
              return parser;
            }
          }
        } catch (err) {
          _didIteratorError = true;
          _iteratorError = err;
        } finally {
          try {
            if (!_iteratorNormalCompletion && _iterator.return != null) {
              _iterator.return();
            }
          } finally {
            if (_didIteratorError) {
              throw _iteratorError;
            }
          }
        }
      }

      return undefined;
    }
  }, {
    key: "getPrefix",
    value: function getPrefix(token) {
      var parser = this.getParser(this.prefix, token);
      return parser ? parser : parser;
    }
  }, {
    key: "getInfix",
    value: function getInfix(token) {
      var parser = this.getParser(this.infix, token);
      return parser ? parser : parser;
    }
  }, {
    key: "token",
    get: function get() {
      return this.peek(0);
    }
  }]);

  return ParserContext;
}();

var Parser =
/*#__PURE__*/
function (_EventEmitter) {
  _inherits(Parser, _EventEmitter);

  function Parser(lexer) {
    var _this;

    _classCallCheck(this, Parser);

    _this = _possibleConstructorReturn(this, _getPrototypeOf(Parser).call(this));
    _this.lexer = lexer;

    _defineProperty(_assertThisInitialized(_this), "parseletContext", void 0);

    _defineProperty(_assertThisInitialized(_this), "prefix", void 0);

    _defineProperty(_assertThisInitialized(_this), "infix", void 0);

    _defineProperty(_assertThisInitialized(_this), "ignored", void 0);

    _defineProperty(_assertThisInitialized(_this), "lexerState", void 0);

    _this.prefix = new Map();
    _this.infix = new Map();
    _this.ignored = new Set();
    _this.lexerState = _this.lexer.currentState;
    return _this;
  }

  _createClass(Parser, [{
    key: "parse",
    value: function parse(input, state) {
      var exhaustive = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : true;

      if (!state) {
        state = _Lexer.InitialLexerState;
      }

      this.lexer.initialize(input, state);
      var parserContext = new ParserContext(this.fireEvent.bind(this), this.lexer, this.prefix, this.infix, this.ignored, this.parseletContext);
      var expression = parserContext.parse();

      if (exhaustive && !parserContext.match(_Lexer.TokenType.EOF)) {
        throw new SyntaxError(Error.UnknownToken(parserContext.token));
      }

      var _parserContext$shift = parserContext.shift(),
          offset = _parserContext$shift.offset,
          line = _parserContext$shift.line,
          col = _parserContext$shift.col;

      this.lexerState = {
        offset: offset,
        line: line,
        col: col
      };
      return expression;
    }
  }, {
    key: "setPrefix",
    value: function setPrefix(tokenType, parser) {
      if (!this.prefix.has(tokenType)) {
        this.prefix.set(tokenType, []);
      }

      this.prefix.get(tokenType).push(parser);
    }
  }, {
    key: "setInfix",
    value: function setInfix(tokenType, parser) {
      if (!this.infix.has(tokenType)) {
        this.infix.set(tokenType, []);
      }

      this.infix.get(tokenType).push(parser);
    }
  }, {
    key: "ignore",
    value: function ignore(tokenType) {
      this.ignored.add(tokenType);
    }
  }, {
    key: "state",
    get: function get() {
      return this.lexerState;
    }
  }]);

  return Parser;
}(_EventEmitter2.EventEmitter);

exports.Parser = Parser;