let AST = {
  Program: function(statements, blockParams, strip, locInfo) {
    this.loc = locInfo;
    this.type = 'Program';
    this.body = statements;

    this.blockParams = blockParams;
    this.strip = strip;
  },

  MustacheStatement: function(path, params, hash, escaped, strip, locInfo) {
    this.loc = locInfo;
    this.type = 'MustacheStatement';

    this.path = path;
    this.params = params || [];
    this.hash = hash;
    this.escaped = escaped;

    this.strip = strip;
  },

  BlockStatement: function(path, params, hash, program, inverse, openStrip, inverseStrip, closeStrip, locInfo) {
    this.loc = locInfo;
    this.type = 'BlockStatement';

    this.path = path;
    this.params = params || [];
    this.hash = hash;
    this.program = program;
    this.inverse = inverse;

    this.openStrip = openStrip;
    this.inverseStrip = inverseStrip;
    this.closeStrip = closeStrip;
  },

  PartialStatement: function(name, params, hash, strip, locInfo) {
    this.loc = locInfo;
    this.type = 'PartialStatement';

    this.name = name;
    this.params = params || [];
    this.hash = hash;

    this.indent = '';
    this.strip = strip;
  },

  ContentStatement: function(string, locInfo) {
    this.loc = locInfo;
    this.type = 'ContentStatement';
    this.original = this.value = string;
  },

  CommentStatement: function(comment, strip, locInfo) {
    this.loc = locInfo;
    this.type = 'CommentStatement';
    this.value = comment;

    this.strip = strip;
  },

  SubExpression: function(path, params, hash, locInfo) {
    this.loc = locInfo;

    this.type = 'SubExpression';
    this.path = path;
    this.params = params || [];
    this.hash = hash;
  },

  PathExpression: function(data, depth, parts, original, locInfo) {
    this.loc = locInfo;
    this.type = 'PathExpression';

    this.data = data;
    this.original = original;
    this.parts = parts;
    this.depth = depth;
  },

  StringLiteral: function(string, locInfo) {
    this.loc = locInfo;
    this.type = 'StringLiteral';
    this.original =
      this.value = string;
  },

  NumberLiteral: function(number, locInfo) {
    this.loc = locInfo;
    this.type = 'NumberLiteral';
    this.original =
      this.value = Number(number);
  },

  BooleanLiteral: function(bool, locInfo) {
    this.loc = locInfo;
    this.type = 'BooleanLiteral';
    this.original =
      this.value = bool === 'true';
  },

  UndefinedLiteral: function(locInfo) {
    this.loc = locInfo;
    this.type = 'UndefinedLiteral';
    this.original = this.value = undefined;
  },

  NullLiteral: function(locInfo) {
    this.loc = locInfo;
    this.type = 'NullLiteral';
    this.original = this.value = null;
  },

  Hash: function(pairs, locInfo) {
    this.loc = locInfo;
    this.type = 'Hash';
    this.pairs = pairs;
  },
  HashPair: function(key, value, locInfo) {
    this.loc = locInfo;
    this.type = 'HashPair';
    this.key = key;
    this.value = value;
  },

  // Public API used to evaluate derived attributes regarding AST nodes
  helpers: {
    // a mustache is definitely a helper if:
    // * it is an eligible helper, and
    // * it has at least one parameter or hash segment
    helperExpression: function(node) {
      return !!(node.type === 'SubExpression' || node.params.length || node.hash);
    },

    scopedId: function(path) {
      return (/^\.|this\b/).test(path.original);
    },

    // an ID is simple if it only has one part, and that part is not
    // `..` or `this`.
    simpleId: function(path) {
      return path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth;
    }
  }
};


// Must be exported as an object rather than the root of the module as the jison lexer
// must modify the object to operate properly.
export default AST;