'use strict';

exports.__esModule = true;
// istanbul ignore next

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

var _exception = require('../exception');

var _exception2 = _interopRequireDefault(_exception);

function Visitor() {
  this.parents = [];
}

Visitor.prototype = {
  constructor: Visitor,
  mutating: false,

  // Visits a given value. If mutating, will replace the value if necessary.
  acceptKey: function acceptKey(node, name) {
    var value = this.accept(node[name]);
    if (this.mutating) {
      // Hacky sanity check: This may have a few false positives for type for the helper
      // methods but will generally do the right thing without a lot of overhead.
      if (value && !Visitor.prototype[value.type]) {
        throw new _exception2['default']('Unexpected node type "' + value.type + '" found when accepting ' + name + ' on ' + node.type);
      }
      node[name] = value;
    }
  },

  // Performs an accept operation with added sanity check to ensure
  // required keys are not removed.
  acceptRequired: function acceptRequired(node, name) {
    this.acceptKey(node, name);

    if (!node[name]) {
      throw new _exception2['default'](node.type + ' requires ' + name);
    }
  },

  // Traverses a given array. If mutating, empty respnses will be removed
  // for child elements.
  acceptArray: function acceptArray(array) {
    for (var i = 0, l = array.length; i < l; i++) {
      this.acceptKey(array, i);

      if (!array[i]) {
        array.splice(i, 1);
        i--;
        l--;
      }
    }
  },

  accept: function accept(object) {
    if (!object) {
      return;
    }

    /* istanbul ignore next: Sanity code */
    if (!this[object.type]) {
      throw new _exception2['default']('Unknown type: ' + object.type, object);
    }

    if (this.current) {
      this.parents.unshift(this.current);
    }
    this.current = object;

    var ret = this[object.type](object);

    this.current = this.parents.shift();

    if (!this.mutating || ret) {
      return ret;
    } else if (ret !== false) {
      return object;
    }
  },

  Program: function Program(program) {
    this.acceptArray(program.body);
  },

  MustacheStatement: visitSubExpression,
  Decorator: visitSubExpression,

  BlockStatement: visitBlock,
  DecoratorBlock: visitBlock,

  PartialStatement: visitPartial,
  PartialBlockStatement: function PartialBlockStatement(partial) {
    visitPartial.call(this, partial);

    this.acceptKey(partial, 'program');
  },

  ContentStatement: function ContentStatement() /* content */{},
  CommentStatement: function CommentStatement() /* comment */{},

  SubExpression: visitSubExpression,

  PathExpression: function PathExpression() /* path */{},

  StringLiteral: function StringLiteral() /* string */{},
  NumberLiteral: function NumberLiteral() /* number */{},
  BooleanLiteral: function BooleanLiteral() /* bool */{},
  UndefinedLiteral: function UndefinedLiteral() /* literal */{},
  NullLiteral: function NullLiteral() /* literal */{},

  Hash: function Hash(hash) {
    this.acceptArray(hash.pairs);
  },
  HashPair: function HashPair(pair) {
    this.acceptRequired(pair, 'value');
  }
};

function visitSubExpression(mustache) {
  this.acceptRequired(mustache, 'path');
  this.acceptArray(mustache.params);
  this.acceptKey(mustache, 'hash');
}
function visitBlock(block) {
  visitSubExpression.call(this, block);

  this.acceptKey(block, 'program');
  this.acceptKey(block, 'inverse');
}
function visitPartial(partial) {
  this.acceptRequired(partial, 'name');
  this.acceptArray(partial.params);
  this.acceptKey(partial, 'hash');
}

exports['default'] = Visitor;
module.exports = exports['default'];
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If mutating, will replace the value if necessary.\n  acceptKey: function(node, name) {\n    let value = this.accept(node[name]);\n    if (this.mutating) {\n      // Hacky sanity check: This may have a few false positives for type for the helper\n      // methods but will generally do the right thing without a lot of overhead.\n      if (value && !Visitor.prototype[value.type]) {\n        throw new Exception('Unexpected node type \"' + value.type + '\" found when accepting ' + name + ' on ' + node.type);\n      }\n      node[name] = value;\n    }\n  },\n\n  // Performs an accept operation with added sanity check to ensure\n  // required keys are not removed.\n  acceptRequired: function(node, name) {\n    this.acceptKey(node, name);\n\n    if (!node[name]) {\n      throw new Exception(node.type + ' requires ' + name);\n    }\n  },\n\n  // Traverses a given array. If mutating, empty respnses will be removed\n  // for child elements.\n  acceptArray: function(array) {\n    for (let i = 0, l = array.length; i < l; i++) {\n      this.acceptKey(array, i);\n\n      if (!array[i]) {\n        array.splice(i, 1);\n        i--;\n        l--;\n      }\n    }\n  },\n\n  accept: function(object) {\n    if (!object) {\n      return;\n    }\n\n    /* istanbul ignore next: Sanity code */\n    if (!this[object.type]) {\n      throw new Exception('Unknown type: ' + object.type, object);\n    }\n\n    if (this.current) {\n      this.parents.unshift(this.current);\n    }\n    this.current = object;\n\n    let ret = this[object.type](object);\n\n    this.current = this.parents.shift();\n\n    if (!this.mutating || ret) {\n      return ret;\n    } else if (ret !== false) {\n      return object;\n    }\n  },\n\n  Program: function(program) {\n    this.acceptArray(program.body);\n  },\n\n  MustacheStatement: visitSubExpression,\n  Decorator: visitSubExpression,\n\n  BlockStatement: visitBlock,\n  DecoratorBlock: visitBlock,\n\n  PartialStatement: visitPartial,\n  PartialBlockStatement: function(partial) {\n    visitPartial.call(this, partial);\n\n    this.acceptKey(partial, 'program');\n  },\n\n  ContentStatement: function(/* content */) {},\n  CommentStatement: function(/* comment */) {},\n\n  SubExpression: visitSubExpression,\n\n  PathExpression: function(/* path */) {},\n\n  StringLiteral: function(/* string */) {},\n  NumberLiteral: function(/* number */) {},\n  BooleanLiteral: function(/* bool */) {},\n  UndefinedLiteral: function(/* literal */) {},\n  NullLiteral: function(/* literal */) {},\n\n  Hash: function(hash) {\n    this.acceptArray(hash.pairs);\n  },\n  HashPair: function(pair) {\n    this.acceptRequired(pair, 'value');\n  }\n};\n\nfunction visitSubExpression(mustache) {\n  this.acceptRequired(mustache, 'path');\n  this.acceptArray(mustache.params);\n  this.acceptKey(mustache, 'hash');\n}\nfunction visitBlock(block) {\n  visitSubExpression.call(this, block);\n\n  this.acceptKey(block, 'program');\n  this.acceptKey(block, 'inverse');\n}\nfunction visitPartial(partial) {\n  this.acceptRequired(partial, 'name');\n  this.acceptArray(partial.params);\n  this.acceptKey(partial, 'hash');\n}\n\nexport default Visitor;\n"]}