sucrase/dist/sucrase-babylon/parser/statement.js

Super-fast alternative to Babel for when you can target modern JS runtimes

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var N = _interopRequireWildcard(require("../types"));

var _types2 = require("../tokenizer/types");

var _expression = _interopRequireDefault(require("./expression"));

var _whitespace = require("../util/whitespace");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

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; } }

/* eslint max-len: 0 */
// Reused empty array added for node fields that are always empty.
const empty = [];
const loopLabel = {
  kind: "loop"
},
      switchLabel = {
  kind: "switch"
};

class StatementParser extends _expression.default {
  // ### Statement parsing
  // Parse a program. Initializes the parser, reads any number of
  // statements, and wraps them in a Program node.  Optionally takes a
  // `program` argument.  If present, the statements will be appended
  // to its body instead of creating a new node.
  parseTopLevel(file, program) {
    program.sourceType = this.options.sourceType;
    this.parseBlockBody(program, true, true, _types2.types.eof);
    file.program = this.finishNode(program, "Program");
    file.comments = this.state.comments;
    if (this.options.tokens) file.tokens = this.state.tokens;
    return this.finishNode(file, "File");
  } // TODO


  stmtToDirective(stmt) {
    const expr = stmt.expression;
    const directiveLiteral = this.startNodeAt(expr.start, expr.loc.start);
    const directive = this.startNodeAt(stmt.start, stmt.loc.start);
    const raw = this.input.slice(expr.start, expr.end);
    const val = directiveLiteral.value = raw.slice(1, -1); // remove quotes

    this.addExtra(directiveLiteral, "raw", raw);
    this.addExtra(directiveLiteral, "rawValue", val);
    directive.value = this.finishNodeAt(directiveLiteral, "DirectiveLiteral", expr.end, expr.loc.end);
    return this.finishNodeAt(directive, "Directive", stmt.end, stmt.loc.end);
  } // Parse a single statement.
  //
  // If expecting a statement and finding a slash operator, parse a
  // regular expression literal. This is to handle cases like
  // `if (foo) /blah/.exec(foo)`, where looking at the previous token
  // does not help.


  parseStatement(declaration, topLevel) {
    if (this.match(_types2.types.at)) {
      this.parseDecorators(true);
    }

    return this.parseStatementContent(declaration, topLevel);
  }

  parseStatementContent(declaration, topLevel) {
    const starttype = this.state.type;
    const node = this.startNode(); // Most types of statements are recognized by the keyword they
    // start with. Many are trivial to parse, some require a bit of
    // complexity.

    switch (starttype) {
      case _types2.types._break:
      case _types2.types._continue:
        // $FlowFixMe
        return this.parseBreakContinueStatement(node, starttype.keyword);

      case _types2.types._debugger:
        return this.parseDebuggerStatement(node);

      case _types2.types._do:
        return this.parseDoStatement(node);

      case _types2.types._for:
        return this.parseForStatement(node);

      case _types2.types._function:
        if (this.lookahead().type === _types2.types.dot) break;
        if (!declaration) this.unexpected();
        return this.parseFunctionStatement(node);

      case _types2.types._class:
        if (!declaration) this.unexpected();
        return this.parseClass(node, true);

      case _types2.types._if:
        return this.parseIfStatement(node);

      case _types2.types._return:
        return this.parseReturnStatement(node);

      case _types2.types._switch:
        return this.parseSwitchStatement(node);

      case _types2.types._throw:
        return this.parseThrowStatement(node);

      case _types2.types._try:
        return this.parseTryStatement(node);

      case _types2.types._let:
      case _types2.types._const:
        if (!declaration) this.unexpected();
      // NOTE: falls through to _var

      case _types2.types._var:
        return this.parseVarStatement(node, starttype);

      case _types2.types._while:
        return this.parseWhileStatement(node);

      case _types2.types._with:
        return this.parseWithStatement(node);

      case _types2.types.braceL:
        return this.parseBlock();

      case _types2.types.semi:
        return this.parseEmptyStatement(node);

      case _types2.types._export:
      case _types2.types._import:
        {
          const nextToken = this.lookahead();

          if (nextToken.type === _types2.types.parenL || nextToken.type === _types2.types.dot) {
            break;
          }

          if (!this.options.allowImportExportEverywhere && !topLevel) {
            this.raise(this.state.start, "'import' and 'export' may only appear at the top level");
          }

          this.next();
          let result;

          if (starttype == _types2.types._import) {
            result = this.parseImport(node);
          } else {
            result = this.parseExport(node);
          }

          this.assertModuleNodeAllowed(node);
          return result;
        }

      case _types2.types.name:
        if (this.state.value === "async") {
          // peek ahead and see if next token is a function
          const state = this.state.clone();
          this.next();

          if (this.match(_types2.types._function) && !this.canInsertSemicolon()) {
            this.expect(_types2.types._function);
            return this.parseFunction(node, true, false, true);
          } else {
            this.state = state;
          }
        }

    } // If the statement does not start with a statement keyword or a
    // brace, it's an ExpressionStatement or LabeledStatement. We
    // simply start parsing an expression, and afterwards, if the
    // next token is a colon and the expression was a simple
    // Identifier node, we switch to interpreting it as a label.


    const maybeName = this.state.value;
    const expr = this.parseExpression();

    if (starttype === _types2.types.name && expr.type === "Identifier" && this.eat(_types2.types.colon)) {
      return this.parseLabeledStatement(node, maybeName, expr);
    } else {
      return this.parseExpressionStatement(node, expr);
    }
  }

  assertModuleNodeAllowed(node) {
    if (!this.options.allowImportExportEverywhere && !this.inModule) {
      this.raise(node.start, `'import' and 'export' may appear only with 'sourceType: "module"'`);
    }
  }

  takeDecorators(node) {
    const decorators = this.state.decoratorStack[this.state.decoratorStack.length - 1];

    if (decorators.length) {
      node.decorators = decorators;
      this.resetStartLocationFromNode(node, decorators[0]);
      this.state.decoratorStack[this.state.decoratorStack.length - 1] = [];
    }
  }

  parseDecorators(allowExport) {
    if (this.hasPlugin("decorators2")) {
      allowExport = false;
    }

    const currentContextDecorators = this.state.decoratorStack[this.state.decoratorStack.length - 1];

    while (this.match(_types2.types.at)) {
      const decorator = this.parseDecorator();
      currentContextDecorators.push(decorator);
    }

    if (this.match(_types2.types._export)) {
      if (allowExport) {
        return;
      } else {
        this.raise(this.state.start, "Using the export keyword between a decorator and a class is not allowed. Please use `export @dec class` instead");
      }
    }

    if (!this.match(_types2.types._class)) {
      this.raise(this.state.start, "Leading decorators must be attached to a class declaration");
    }
  }

  parseDecorator() {
    this.expectOnePlugin(["decorators", "decorators2"]);
    const node = this.startNode();
    this.next();

    if (this.hasPlugin("decorators2")) {
      const startPos = this.state.start;
      const startLoc = this.state.startLoc;
      let expr = this.parseIdentifier(false);

      while (this.eat(_types2.types.dot)) {
        const node = this.startNodeAt(startPos, startLoc);
        node.object = expr;
        node.property = this.parseIdentifier(true);
        node.computed = false;
        expr = this.finishNode(node, "MemberExpression");
      }

      if (this.eat(_types2.types.parenL)) {
        const node = this.startNodeAt(startPos, startLoc);
        node.callee = expr; // Every time a decorator class expression is evaluated, a new empty array is pushed onto the stack
        // So that the decorators of any nested class expressions will be dealt with separately

        this.state.decoratorStack.push([]);
        node.arguments = this.parseCallExpressionArguments(_types2.types.parenR, false);
        this.state.decoratorStack.pop();
        expr = this.finishNode(node, "CallExpression");
        this.toReferencedList(expr.arguments);
      }

      node.expression = expr;
    } else {
      node.expression = this.parseMaybeAssign();
    }

    return this.finishNode(node, "Decorator");
  }

  parseBreakContinueStatement(node, keyword) {
    const isBreak = keyword === "break";
    this.next();

    if (this.isLineTerminator()) {
      node.label = null;
    } else if (!this.match(_types2.types.name)) {
      this.unexpected();
    } else {
      node.label = this.parseIdentifier();
      this.semicolon();
    } // Verify that there is an actual destination to break or
    // continue to.


    let i;

    for (i = 0; i < this.state.labels.length; ++i) {
      const lab = this.state.labels[i];

      if (node.label == null || lab.name === node.label.name) {
        if (lab.kind != null && (isBreak || lab.kind === "loop")) break;
        if (node.label && isBreak) break;
      }
    }

    if (i === this.state.labels.length) {
      this.raise(node.start, "Unsyntactic " + keyword);
    }

    return this.finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement");
  }

  parseDebuggerStatement(node) {
    this.next();
    this.semicolon();
    return this.finishNode(node, "DebuggerStatement");
  }

  parseDoStatement(node) {
    this.next();
    this.state.labels.push(loopLabel);
    node.body = this.parseStatement(false);
    this.state.labels.pop();
    this.expect(_types2.types._while);
    node.test = this.parseParenExpression();
    this.eat(_types2.types.semi);
    return this.finishNode(node, "DoWhileStatement");
  } // Disambiguating between a `for` and a `for`/`in` or `for`/`of`
  // loop is non-trivial. Basically, we have to parse the init `var`
  // statement or expression, disallowing the `in` operator (see
  // the second parameter to `parseExpression`), and then check
  // whether the next token is `in` or `of`. When there is no init
  // part (semicolon immediately after the opening parenthesis), it
  // is a regular `for` loop.


  parseForStatement(node) {
    this.next();
    this.state.labels.push(loopLabel);
    let forAwait = false;

    if (this.state.inAsync && this.isContextual("await")) {
      this.expectPlugin("asyncGenerators");
      forAwait = true;
      this.next();
    }

    this.expect(_types2.types.parenL);

    if (this.match(_types2.types.semi)) {
      if (forAwait) {
        this.unexpected();
      }

      return this.parseFor(node, null);
    }

    if (this.match(_types2.types._var) || this.match(_types2.types._let) || this.match(_types2.types._const)) {
      const init = this.startNode();
      const varKind = this.state.type;
      this.next();
      this.parseVar(init, true, varKind);
      this.finishNode(init, "VariableDeclaration");

      if (this.match(_types2.types._in) || this.isContextual("of")) {
        if (init.declarations.length === 1 && !init.declarations[0].init) {
          return this.parseForIn(node, init, forAwait);
        }
      }

      if (forAwait) {
        this.unexpected();
      }

      return this.parseFor(node, init);
    }

    const refShorthandDefaultPos = {
      start: 0
    };
    const init = this.parseExpression(true, refShorthandDefaultPos);

    if (this.match(_types2.types._in) || this.isContextual("of")) {
      const description = this.isContextual("of") ? "for-of statement" : "for-in statement";
      this.toAssignable(init, undefined, description);
      this.checkLVal(init, undefined, undefined, description);
      return this.parseForIn(node, init, forAwait);
    } else if (refShorthandDefaultPos.start) {
      this.unexpected(refShorthandDefaultPos.start);
    }

    if (forAwait) {
      this.unexpected();
    }

    return this.parseFor(node, init);
  }

  parseFunctionStatement(node) {
    this.next();
    return this.parseFunction(node, true);
  }

  parseIfStatement(node) {
    this.next();
    node.test = this.parseParenExpression();
    node.consequent = this.parseStatement(false);
    node.alternate = this.eat(_types2.types._else) ? this.parseStatement(false) : null;
    return this.finishNode(node, "IfStatement");
  }

  parseReturnStatement(node) {
    if (!this.state.inFunction && !this.options.allowReturnOutsideFunction) {
      this.raise(this.state.start, "'return' outside of function");
    }

    this.next(); // In `return` (and `break`/`continue`), the keywords with
    // optional arguments, we eagerly look for a semicolon or the
    // possibility to insert one.

    if (this.isLineTerminator()) {
      node.argument = null;
    } else {
      node.argument = this.parseExpression();
      this.semicolon();
    }

    return this.finishNode(node, "ReturnStatement");
  }

  parseSwitchStatement(node) {
    this.next();
    node.discriminant = this.parseParenExpression();
    const cases = node.cases = [];
    this.expect(_types2.types.braceL);
    this.state.labels.push(switchLabel); // Statements under must be grouped (by label) in SwitchCase
    // nodes. `cur` is used to keep the node that we are currently
    // adding statements to.

    let cur;

    for (let sawDefault; !this.match(_types2.types.braceR);) {
      if (this.match(_types2.types._case) || this.match(_types2.types._default)) {
        const isCase = this.match(_types2.types._case);
        if (cur) this.finishNode(cur, "SwitchCase");
        cases.push(cur = this.startNode());
        cur.consequent = [];
        this.next();

        if (isCase) {
          cur.test = this.parseExpression();
        } else {
          if (sawDefault) {
            this.raise(this.state.lastTokStart, "Multiple default clauses");
          }

          sawDefault = true;
          cur.test = null;
        }

        this.expect(_types2.types.colon);
      } else {
        if (cur) {
          cur.consequent.push(this.parseStatement(true));
        } else {
          this.unexpected();
        }
      }
    }

    if (cur) this.finishNode(cur, "SwitchCase");
    this.next(); // Closing brace

    this.state.labels.pop();
    return this.finishNode(node, "SwitchStatement");
  }

  parseThrowStatement(node) {
    this.next();

    if (_whitespace.lineBreak.test(this.input.slice(this.state.lastTokEnd, this.state.start))) {
      this.raise(this.state.lastTokEnd, "Illegal newline after throw");
    }

    node.argument = this.parseExpression();
    this.semicolon();
    return this.finishNode(node, "ThrowStatement");
  }

  parseTryStatement(node) {
    this.next();
    node.block = this.parseBlock();
    node.handler = null;

    if (this.match(_types2.types._catch)) {
      const clause = this.startNode();
      this.next();

      if (this.match(_types2.types.parenL)) {
        this.expect(_types2.types.parenL);
        clause.param = this.parseBindingAtom();
        const clashes = Object.create(null);
        this.checkLVal(clause.param, true, clashes, "catch clause");
        this.expect(_types2.types.parenR);
      } else {
        this.expectPlugin("optionalCatchBinding");
        clause.param = null;
      }

      clause.body = this.parseBlock();
      node.handler = this.finishNode(clause, "CatchClause");
    }

    node.guardedHandlers = empty;
    node.finalizer = this.eat(_types2.types._finally) ? this.parseBlock() : null;

    if (!node.handler && !node.finalizer) {
      this.raise(node.start, "Missing catch or finally clause");
    }

    return this.finishNode(node, "TryStatement");
  }

  parseVarStatement(node, kind) {
    this.next();
    this.parseVar(node, false, kind);
    this.semicolon();
    return this.finishNode(node, "VariableDeclaration");
  }

  parseWhileStatement(node) {
    this.next();
    node.test = this.parseParenExpression();
    this.state.labels.push(loopLabel);
    node.body = this.parseStatement(false);
    this.state.labels.pop();
    return this.finishNode(node, "WhileStatement");
  }

  parseWithStatement(node) {
    if (this.state.strict) {
      this.raise(this.state.start, "'with' in strict mode");
    }

    this.next();
    node.object = this.parseParenExpression();
    node.body = this.parseStatement(false);
    return this.finishNode(node, "WithStatement");
  }

  parseEmptyStatement(node) {
    this.next();
    return this.finishNode(node, "EmptyStatement");
  }

  parseLabeledStatement(node, maybeName, expr) {
    for (const label of this.state.labels) {
      if (label.name === maybeName) {
        this.raise(expr.start, `Label '${maybeName}' is already declared`);
      }
    }

    const kind = this.state.type.isLoop ? "loop" : this.match(_types2.types._switch) ? "switch" : null;

    for (let i = this.state.labels.length - 1; i >= 0; i--) {
      const label = this.state.labels[i];

      if (label.statementStart === node.start) {
        label.statementStart = this.state.start;
        label.kind = kind;
      } else {
        break;
      }
    }

    this.state.labels.push({
      name: maybeName,
      kind: kind,
      statementStart: this.state.start
    });
    node.body = this.parseStatement(true);

    if (node.body.type == "ClassDeclaration" || node.body.type == "VariableDeclaration" && node.body.kind !== "var" || node.body.type == "FunctionDeclaration" && (this.state.strict || node.body.generator || node.body.async)) {
      this.raise(node.body.start, "Invalid labeled declaration");
    }

    this.state.labels.pop();
    node.label = expr;
    return this.finishNode(node, "LabeledStatement");
  }

  parseExpressionStatement(node, expr) {
    node.expression = expr;
    this.semicolon();
    return this.finishNode(node, "ExpressionStatement");
  } // Parse a semicolon-enclosed block of statements, handling `"use
  // strict"` declarations when `allowStrict` is true (used for
  // function bodies).


  parseBlock(allowDirectives) {
    const node = this.startNode();
    this.expect(_types2.types.braceL);
    this.parseBlockBody(node, allowDirectives, false, _types2.types.braceR);
    return this.finishNode(node, "BlockStatement");
  }

  isValidDirective(stmt) {
    return stmt.type === "ExpressionStatement" && stmt.expression.type === "StringLiteral" && !stmt.expression.extra.parenthesized;
  }

  parseBlockBody(node, allowDirectives, topLevel, end) {
    const body = node.body = [];
    const directives = node.directives = [];
    this.parseBlockOrModuleBlockBody(body, allowDirectives ? directives : undefined, topLevel, end);
  } // Undefined directives means that directives are not allowed.


  parseBlockOrModuleBlockBody(body, directives, topLevel, end) {
    let parsedNonDirective = false;
    let oldStrict;
    let octalPosition;

    while (!this.eat(end)) {
      if (!parsedNonDirective && this.state.containsOctal && !octalPosition) {
        octalPosition = this.state.octalPosition;
      }

      const stmt = this.parseStatement(true, topLevel);

      if (directives && !parsedNonDirective && this.isValidDirective(stmt)) {
        const directive = this.stmtToDirective(stmt);
        directives.push(directive);

        if (oldStrict === undefined && directive.value.value === "use strict") {
          oldStrict = this.state.strict;
          this.setStrict(true);

          if (octalPosition) {
            this.raise(octalPosition, "Octal literal in strict mode");
          }
        }

        continue;
      }

      parsedNonDirective = true;
      body.push(stmt);
    }

    if (oldStrict === false) {
      this.setStrict(false);
    }
  } // Parse a regular `for` loop. The disambiguation code in
  // `parseStatement` will already have parsed the init statement or
  // expression.


  parseFor(node, init) {
    node.init = init;
    this.expect(_types2.types.semi);
    node.test = this.match(_types2.types.semi) ? null : this.parseExpression();
    this.expect(_types2.types.semi);
    node.update = this.match(_types2.types.parenR) ? null : this.parseExpression();
    this.expect(_types2.types.parenR);
    node.body = this.parseStatement(false);
    this.state.labels.pop();
    return this.finishNode(node, "ForStatement");
  } // Parse a `for`/`in` and `for`/`of` loop, which are almost
  // same from parser's perspective.


  parseForIn(node, init, forAwait) {
    const type = this.match(_types2.types._in) ? "ForInStatement" : "ForOfStatement";

    if (forAwait) {
      this.eatContextual("of");
    } else {
      this.next();
    }

    if (type === "ForOfStatement") {
      node.await = !!forAwait;
    }

    node.left = init;
    node.right = this.parseExpression();
    this.expect(_types2.types.parenR);
    node.body = this.parseStatement(false);
    this.state.labels.pop();
    return this.finishNode(node, type);
  } // Parse a list of variable declarations.


  parseVar(node, isFor, kind) {
    const declarations = node.declarations = []; // $FlowFixMe

    node.kind = kind.keyword;

    for (;;) {
      const decl = this.startNode();
      this.parseVarHead(decl);

      if (this.eat(_types2.types.eq)) {
        decl.init = this.parseMaybeAssign(isFor);
      } else {
        if (kind === _types2.types._const && !(this.match(_types2.types._in) || this.isContextual("of"))) {
          // `const` with no initializer is allowed in TypeScript. It could be a declaration `const x: number;`.
          if (!this.hasPlugin("typescript")) {
            this.unexpected();
          }
        } else if (decl.id.type !== "Identifier" && !(isFor && (this.match(_types2.types._in) || this.isContextual("of")))) {
          this.raise(this.state.lastTokEnd, "Complex binding patterns require an initialization value");
        }

        decl.init = null;
      }

      declarations.push(this.finishNode(decl, "VariableDeclarator"));
      if (!this.eat(_types2.types.comma)) break;
    }

    return node;
  }

  parseVarHead(decl) {
    decl.id = this.parseBindingAtom();
    this.checkLVal(decl.id, true, undefined, "variable declaration");
  } // Parse a function declaration or literal (depending on the
  // `isStatement` parameter).


  parseFunction(node, isStatement, allowExpressionBody, isAsync, optionalId) {
    const oldInFunc = this.state.inFunction;
    const oldInMethod = this.state.inMethod;
    const oldInGenerator = this.state.inGenerator;
    this.state.inFunction = true;
    this.state.inMethod = false;
    this.initFunction(node, isAsync);

    if (this.match(_types2.types.star)) {
      if (node.async) {
        this.expectPlugin("asyncGenerators");
      }

      node.generator = true;
      this.next();
    }

    if (isStatement && !optionalId && !this.match(_types2.types.name) && !this.match(_types2.types._yield)) {
      this.unexpected();
    } // When parsing function expression, the binding identifier is parsed
    // according to the rules inside the function.
    // e.g. (function* yield() {}) is invalid because "yield" is disallowed in
    // generators.
    // This isn't the case with function declarations: function* yield() {} is
    // valid because yield is parsed as if it was outside the generator.
    // Therefore, this.state.inGenerator is set before or after parsing the
    // function id according to the "isStatement" parameter.


    if (!isStatement) this.state.inGenerator = node.generator;

    if (this.match(_types2.types.name) || this.match(_types2.types._yield)) {
      node.id = this.parseBindingIdentifier();
    }

    if (isStatement) this.state.inGenerator = node.generator;
    this.parseFunctionParams(node);
    this.parseFunctionBodyAndFinish(node, isStatement ? "FunctionDeclaration" : "FunctionExpression", allowExpressionBody);
    this.state.inFunction = oldInFunc;
    this.state.inMethod = oldInMethod;
    this.state.inGenerator = oldInGenerator;
    return node;
  }

  parseFunctionParams(node, allowModifiers) {
    const oldInParameters = this.state.inParameters;
    this.state.inParameters = true;
    this.expect(_types2.types.parenL);
    node.params = this.parseBindingList(_types2.types.parenR,
    /* allowEmpty */
    false, allowModifiers);
    this.state.inParameters = oldInParameters;
  } // Parse a class declaration or literal (depending on the
  // `isStatement` parameter).


  parseClass(node, isStatement, optionalId) {
    this.next();
    this.takeDecorators(node);
    this.parseClassId(node, isStatement, optionalId);
    this.parseClassSuper(node);
    this.parseClassBody(node);
    return this.finishNode(node, isStatement ? "ClassDeclaration" : "ClassExpression");
  }

  isClassProperty() {
    return this.match(_types2.types.eq) || this.match(_types2.types.semi) || this.match(_types2.types.braceR);
  }

  isClassMethod() {
    return this.match(_types2.types.parenL);
  }

  isNonstaticConstructor(method) {
    return !method.computed && !method.static && (method.key.name === "constructor" || // Identifier
    method.key.value === "constructor") // String literal
    ;
  }

  parseClassBody(node) {
    // class bodies are implicitly strict
    const oldStrict = this.state.strict;
    this.state.strict = true;
    this.state.classLevel++;
    const state = {
      hadConstructor: false
    };
    let decorators = [];
    const classBody = this.startNode();
    classBody.body = [];
    this.expect(_types2.types.braceL);

    while (!this.eat(_types2.types.braceR)) {
      if (this.eat(_types2.types.semi)) {
        if (decorators.length > 0) {
          this.raise(this.state.lastTokEnd, "Decorators must not be followed by a semicolon");
        }

        continue;
      }

      if (this.match(_types2.types.at)) {
        decorators.push(this.parseDecorator());
        continue;
      }

      const member = this.startNode(); // steal the decorators if there are any

      if (decorators.length) {
        member.decorators = decorators;
        this.resetStartLocationFromNode(member, decorators[0]);
        decorators = [];
      }

      this.parseClassMember(classBody, member, state);

      if (this.hasPlugin("decorators2") && ["method", "get", "set"].indexOf(member.kind) === -1 && member.decorators && member.decorators.length > 0) {
        this.raise(member.start, "Stage 2 decorators may only be used with a class or a class method");
      }
    }

    if (decorators.length) {
      this.raise(this.state.start, "You have trailing decorators with no method");
    }

    node.body = this.finishNode(classBody, "ClassBody");
    this.state.classLevel--;
    this.state.strict = oldStrict;
  }

  parseClassMember(classBody, member, state) {
    let isStatic = false;

    if (this.match(_types2.types.name) && this.state.value === "static") {
      const key = this.parseIdentifier(true); // eats 'static'

      if (this.isClassMethod()) {
        const method = member; // a method named 'static'

        method.kind = "method";
        method.computed = false;
        method.key = key;
        method.static = false;
        this.pushClassMethod(classBody, method, false, false,
        /* isConstructor */
        false);
        return;
      } else if (this.isClassProperty()) {
        const prop = member; // a property named 'static'

        prop.computed = false;
        prop.key = key;
        prop.static = false;
        classBody.body.push(this.parseClassProperty(prop));
        return;
      } // otherwise something static


      isStatic = true;
    }

    this.parseClassMemberWithIsStatic(classBody, member, state, isStatic);
  }

  parseClassMemberWithIsStatic(classBody, member, state, isStatic) {
    const publicMethod = member;
    const privateMethod = member;
    const publicProp = member;
    const privateProp = member;
    const method = publicMethod;
    const publicMember = publicMethod;
    member.static = isStatic;

    if (this.eat(_types2.types.star)) {
      // a generator
      method.kind = "method";
      this.parseClassPropertyName(method);

      if (method.key.type === "PrivateName") {
        // Private generator method
        this.pushClassPrivateMethod(classBody, privateMethod, true, false);
        return;
      }

      if (this.isNonstaticConstructor(publicMethod)) {
        this.raise(publicMethod.key.start, "Constructor can't be a generator");
      }

      this.pushClassMethod(classBody, publicMethod, true, false,
      /* isConstructor */
      false);
      return;
    }

    const key = this.parseClassPropertyName(member);
    const isPrivate = key.type === "PrivateName"; // Check the key is not a computed expression or string literal.

    const isSimple = key.type === "Identifier";
    this.parsePostMemberNameModifiers(publicMember);

    if (this.isClassMethod()) {
      method.kind = "method";

      if (isPrivate) {
        this.pushClassPrivateMethod(classBody, privateMethod, false, false);
        return;
      } // a normal method


      const isConstructor = this.isNonstaticConstructor(publicMethod);

      if (isConstructor) {
        publicMethod.kind = "constructor";

        if (publicMethod.decorators) {
          this.raise(publicMethod.start, "You can't attach decorators to a class constructor");
        } // TypeScript allows multiple overloaded constructor declarations.


        if (state.hadConstructor && !this.hasPlugin("typescript")) {
          this.raise(key.start, "Duplicate constructor in the same class");
        }

        state.hadConstructor = true;
      }

      this.pushClassMethod(classBody, publicMethod, false, false, isConstructor);
    } else if (this.isClassProperty()) {
      if (isPrivate) {
        this.pushClassPrivateProperty(classBody, privateProp);
      } else {
        this.pushClassProperty(classBody, publicProp);
      }
    } else if (isSimple && key.name === "async" && !this.isLineTerminator()) {
      // an async method
      const isGenerator = this.match(_types2.types.star);

      if (isGenerator) {
        this.expectPlugin("asyncGenerators");
        this.next();
      }

      method.kind = "method"; // The so-called parsed name would have been "async": get the real name.

      this.parseClassPropertyName(method);

      if (method.key.type === "PrivateName") {
        // private async method
        this.pushClassPrivateMethod(classBody, privateMethod, isGenerator, true);
      } else {
        if (this.isNonstaticConstructor(publicMethod)) {
          this.raise(publicMethod.key.start, "Constructor can't be an async function");
        }

        this.pushClassMethod(classBody, publicMethod, isGenerator, true,
        /* isConstructor */
        false);
      }
    } else if (isSimple && (key.name === "get" || key.name === "set") && !(this.isLineTerminator() && this.match(_types2.types.star))) {
      // `get\n*` is an uninitialized property named 'get' followed by a generator.
      // a getter or setter
      method.kind = key.name; // The so-called parsed name would have been "get/set": get the real name.

      this.parseClassPropertyName(publicMethod);

      if (method.key.type === "PrivateName") {
        // private getter/setter
        this.pushClassPrivateMethod(classBody, privateMethod, false, false);
      } else {
        if (this.isNonstaticConstructor(publicMethod)) {
          this.raise(publicMethod.key.start, "Constructor can't have get/set modifier");
        }

        this.pushClassMethod(classBody, publicMethod, false, false,
        /* isConstructor */
        false);
      }

      this.checkGetterSetterParamCount(publicMethod);
    } else if (this.isLineTerminator()) {
      // an uninitialized class property (due to ASI, since we don't otherwise recognize the next token)
      if (isPrivate) {
        this.pushClassPrivateProperty(classBody, privateProp);
      } else {
        this.pushClassProperty(classBody, publicProp);
      }
    } else {
      this.unexpected();
    }
  }

  parseClassPropertyName(member) {
    const key = this.parsePropertyName(member);

    if (!member.computed && member.static && (key.name === "prototype" || key.value === "prototype")) {
      this.raise(key.start, "Classes may not have static property named prototype");
    }

    if (key.type === "PrivateName" && key.id.name === "constructor") {
      this.raise(key.start, "Classes may not have a private field named '#constructor'");
    }

    return key;
  }

  pushClassProperty(classBody, prop) {
    // This only affects properties, not methods.
    if (this.isNonstaticConstructor(prop)) {
      this.raise(prop.key.start, "Classes may not have a non-static field named 'constructor'");
    }

    classBody.body.push(this.parseClassProperty(prop));
  }

  pushClassPrivateProperty(classBody, prop) {
    this.expectPlugin("classPrivateProperties", prop.key.start);
    classBody.body.push(this.parseClassPrivateProperty(prop));
  }

  pushClassMethod(classBody, method, isGenerator, isAsync, isConstructor) {
    classBody.body.push(this.parseMethod(method, isGenerator, isAsync, isConstructor, "ClassMethod"));
  }

  pushClassPrivateMethod(classBody, method, isGenerator, isAsync) {
    this.expectPlugin("classPrivateMethods", method.key.start);
    classBody.body.push(this.parseMethod(method, isGenerator, isAsync,
    /* isConstructor */
    false, "ClassPrivateMethod"));
  } // Overridden in typescript.js


  parsePostMemberNameModifiers( // eslint-disable-next-line no-unused-vars
  methodOrProp) {} // Overridden in typescript.js


  parseAccessModifier() {
    return undefined;
  }

  parseClassPrivateProperty(node) {
    this.state.inClassProperty = true;
    node.value = this.eat(_types2.types.eq) ? this.parseMaybeAssign() : null;
    this.semicolon();
    this.state.inClassProperty = false;
    return this.finishNode(node, "ClassPrivateProperty");
  }

  parseClassProperty(node) {
    if (!node.typeAnnotation) {
      this.expectPlugin("classProperties");
    }

    this.state.inClassProperty = true;

    if (this.match(_types2.types.eq)) {
      this.expectPlugin("classProperties");
      this.next();
      node.value = this.parseMaybeAssign();
    } else {
      node.value = null;
    }

    this.semicolon();
    this.state.inClassProperty = false;
    return this.finishNode(node, "ClassProperty");
  }

  parseClassId(node, isStatement, optionalId) {
    if (this.match(_types2.types.name)) {
      node.id = this.parseIdentifier();
    } else {
      if (optionalId || !isStatement) {
        node.id = null;
      } else {
        this.unexpected(null, "A class name is required");
      }
    }
  }

  parseClassSuper(node) {
    node.superClass = this.eat(_types2.types._extends) ? this.parseExprSubscripts() : null;
  } // Parses module export declaration.
  // TODO: better type. Node is an N.AnyExport.


  parseExport(node) {
    // export * from '...'
    if (this.shouldParseExportStar()) {
      this.parseExportStar(node);
      if (node.type === "ExportAllDeclaration") return node;
    } else if (this.isExportDefaultSpecifier()) {
      this.expectPlugin("exportDefaultFrom");
      const specifier = this.startNode();
      specifier.exported = this.parseIdentifier(true);
      const specifiers = [this.finishNode(specifier, "ExportDefaultSpecifier")];
      node.specifiers = specifiers;

      if (this.match(_types2.types.comma) && this.lookahead().type === _types2.types.star) {
        this.expect(_types2.types.comma);
        const specifier = this.startNode();
        this.expect(_types2.types.star);
        this.expectContextual("as");
        specifier.exported = this.parseIdentifier();
        specifiers.push(this.finishNode(specifier, "ExportNamespaceSpecifier"));
      } else {
        this.parseExportSpecifiersMaybe(node);
      }

      this.parseExportFrom(node, true);
    } else if (this.eat(_types2.types._default)) {
      // export default ...
      let expr = this.startNode();
      let needsSemi = false;

      if (this.eat(_types2.types._function)) {
        expr = this.parseFunction(expr, true, false, false, true);
      } else if (this.isContextual("async") && this.lookahead().type === _types2.types._function) {
        // async function declaration
        this.eatContextual("async");
        this.eat(_types2.types._function);
        expr = this.parseFunction(expr, true, false, true, true);
      } else if (this.match(_types2.types._class)) {
        expr = this.parseClass(expr, true, true);
      } else {
        needsSemi = true;
        expr = this.parseMaybeAssign();
      }

      node.declaration = expr;
      if (needsSemi) this.semicolon();
      this.checkExport(node, true, true);
      return this.finishNode(node, "ExportDefaultDeclaration");
    } else if (this.shouldParseExportDeclaration()) {
      if (this.isContextual("async")) {
        const next = this.lookahead(); // export async;

        if (next.type !== _types2.types._function) {
          this.unexpected(next.start, `Unexpected token, expected "function"`);
        }
      }

      node.specifiers = [];
      node.source = null;
      node.declaration = this.parseExportDeclaration(node);
    } else {
      // export { x, y as z } [from '...']
      node.declaration = null;
      node.specifiers = this.parseExportSpecifiers();
      this.parseExportFrom(node);
    }

    this.checkExport(node, true);
    return this.finishNode(node, "ExportNamedDeclaration");
  } // eslint-disable-next-line no-unused-vars


  parseExportDeclaration(node) {
    return this.parseStatement(true);
  }

  isExportDefaultSpecifier() {
    if (this.match(_types2.types.name)) {
      return this.state.value !== "async";
    }

    if (!this.match(_types2.types._default)) {
      return false;
    }

    const lookahead = this.lookahead();
    return lookahead.type === _types2.types.comma || lookahead.type === _types2.types.name && lookahead.value === "from";
  }

  parseExportSpecifiersMaybe(node) {
    if (this.eat(_types2.types.comma)) {
      node.specifiers = node.specifiers.concat(this.parseExportSpecifiers());
    }
  }

  parseExportFrom(node, expect) {
    if (this.eatContextual("from")) {
      node.source = this.match(_types2.types.string) ? this.parseExprAtom() : this.unexpected();
      this.checkExport(node);
    } else {
      if (expect) {
        this.unexpected();
      } else {
        node.source = null;
      }
    }

    this.semicolon();
  }

  shouldParseExportStar() {
    return this.match(_types2.types.star);
  }

  parseExportStar(node) {
    this.expect(_types2.types.star);

    if (this.isContextual("as")) {
      this.parseExportNamespace(node);
    } else {
      this.parseExportFrom(node, true);
      this.finishNode(node, "ExportAllDeclaration");
    }
  }

  parseExportNamespace(node) {
    this.expectPlugin("exportNamespaceFrom");
    const specifier = this.startNodeAt(this.state.lastTokStart, this.state.lastTokStartLoc);
    this.next();
    specifier.exported = this.parseIdentifier(true);
    node.specifiers = [this.finishNode(specifier, "ExportNamespaceSpecifier")];
    this.parseExportSpecifiersMaybe(node);
    this.parseExportFrom(node, true);
  }

  shouldParseExportDeclaration() {
    return this.state.type.keyword === "var" || this.state.type.keyword === "const" || this.state.type.keyword === "let" || this.state.type.keyword === "function" || this.state.type.keyword === "class" || this.isContextual("async") || this.match(_types2.types.at) && this.expectPlugin("decorators2");
  }

  checkExport(node, checkNames, isDefault) {
    if (checkNames) {
      // Check for duplicate exports
      if (isDefault) {
        // Default exports
        this.checkDuplicateExports(node, "default");
      } else if (node.specifiers && node.specifiers.length) {
        // Named exports
        for (const specifier of node.specifiers) {
          this.checkDuplicateExports(specifier, specifier.exported.name);
        }
      } else if (node.declaration) {
        // Exported declarations
        if (node.declaration.type === "FunctionDeclaration" || node.declaration.type === "ClassDeclaration") {
          this.checkDuplicateExports(node, node.declaration.id.name);
        } else if (node.declaration.type === "VariableDeclaration") {
          for (const declaration of node.declaration.declarations) {
            this.checkDeclaration(declaration.id);
          }
        }
      }
    }

    const currentContextDecorators = this.state.decoratorStack[this.state.decoratorStack.length - 1];

    if (currentContextDecorators.length) {
      const isClass = node.declaration && (node.declaration.type === "ClassDeclaration" || node.declaration.type === "ClassExpression");

      if (!node.declaration || !isClass) {
        throw this.raise(node.start, "You can only use decorators on an export when exporting a class");
      }

      this.takeDecorators(node.declaration);
    }
  }

  checkDeclaration(node) {
    if (node.type === "ObjectPattern") {
      for (const prop of node.properties) {
        this.checkDeclaration(prop);
      }
    } else if (node.type === "ArrayPattern") {
      for (const elem of node.elements) {
        if (elem) {
          this.checkDeclaration(elem);
        }
      }
    } else if (node.type === "ObjectProperty") {
      this.checkDeclaration(node.value);
    } else if (node.type === "RestElement") {
      this.checkDeclaration(node.argument);
    } else if (node.type === "Identifier") {
      this.checkDuplicateExports(node, node.name);
    }
  }

  checkDuplicateExports(node, name) {
    if (this.state.exportedIdentifiers.indexOf(name) > -1) {
      this.raiseDuplicateExportError(node, name);
    }

    this.state.exportedIdentifiers.push(name);
  }

  raiseDuplicateExportError(node, name) {
    throw this.raise(node.start, name === "default" ? "Only one default export allowed per module." : `\`${name}\` has already been exported. Exported identifiers must be unique.`);
  } // Parses a comma-separated list of module exports.


  parseExportSpecifiers() {
    const nodes = [];
    let first = true;
    let needsFrom; // export { x, y as z } [from '...']

    this.expect(_types2.types.braceL);

    while (!this.eat(_types2.types.braceR)) {
      if (first) {
        first = false;
      } else {
        this.expect(_types2.types.comma);
        if (this.eat(_types2.types.braceR)) break;
      }

      const isDefault = this.match(_types2.types._default);
      if (isDefault && !needsFrom) needsFrom = true;
      const node = this.startNode();
      node.local = this.parseIdentifier(isDefault);
      node.exported = this.eatContextual("as") ? this.parseIdentifier(true) : node.local.__clone();
      nodes.push(this.finishNode(node, "ExportSpecifier"));
    } // https://github.com/ember-cli/ember-cli/pull/3739


    if (needsFrom && !this.isContextual("from")) {
      this.unexpected();
    }

    return nodes;
  } // Parses import declaration.


  parseImport(node) {
    // import '...'
    if (this.match(_types2.types.string)) {
      node.specifiers = [];
      node.source = this.parseExprAtom();
    } else {
      node.specifiers = [];
      this.parseImportSpecifiers(node);
      this.expectContextual("from");
      node.source = this.match(_types2.types.string) ? this.parseExprAtom() : this.unexpected();
    }

    this.semicolon();
    return this.finishNode(node, "ImportDeclaration");
  } // eslint-disable-next-line no-unused-vars


  shouldParseDefaultImport(node) {
    return this.match(_types2.types.name);
  }

  parseImportSpecifierLocal(node, specifier, type, contextDescription) {
    specifier.local = this.parseIdentifier();
    this.checkLVal(specifier.local, true, undefined, contextDescription);
    node.specifiers.push(this.finishNode(specifier, type));
  } // Parses a comma-separated list of module imports.


  parseImportSpecifiers(node) {
    let first = true;

    if (this.shouldParseDefaultImport(node)) {
      // import defaultObj, { x, y as z } from '...'
      this.parseImportSpecifierLocal(node, this.startNode(), "ImportDefaultSpecifier", "default import specifier");
      if (!this.eat(_types2.types.comma)) return;
    }

    if (this.match(_types2.types.star)) {
      const specifier = this.startNode();
      this.next();
      this.expectContextual("as");
      this.parseImportSpecifierLocal(node, specifier, "ImportNamespaceSpecifier", "import namespace specifier");
      return;
    }

    this.expect(_types2.types.braceL);

    while (!this.eat(_types2.types.braceR)) {
      if (first) {
        first = false;
      } else {
        // Detect an attempt to deep destructure
        if (this.eat(_types2.types.colon)) {
          this.unexpected(null, "ES2015 named imports do not destructure. Use another statement for destructuring after the import.");
        }

        this.expect(_types2.types.comma);
        if (this.eat(_types2.types.braceR)) break;
      }

      this.parseImportSpecifier(node);
    }
  }

  parseImportSpecifier(node) {
    const specifier = this.startNode();
    specifier.imported = this.parseIdentifier(true);

    if (this.eatContextual("as")) {
      specifier.local = this.parseIdentifier();
    } else {
      this.checkReservedWord(specifier.imported.name, specifier.start, true, true);
      specifier.local = specifier.imported.__clone();
    }

    this.checkLVal(specifier.local, true, undefined, "import specifier");
    node.specifiers.push(this.finishNode(specifier, "ImportSpecifier"));
  }

}

exports.default = StatementParser;