build: Add some required modules for node

1 files changed, 1019 insertions, 0 deletions

diff --git a/node_modules/snapdragon-util/index.js b/node_modules/snapdragon-util/index.js
new file mode 100644
index 0000000..68a030e
--- /dev/null
+++ b/node_modules/snapdragon-util/index.js
@@ -0,0 +1,1019 @@
+'use strict';
+
+var typeOf = require('kind-of');
+var utils = module.exports;
+
+/**
+ * Returns true if the given value is a node.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var node = new Node({type: 'foo'});
+ * console.log(utils.isNode(node)); //=> true
+ * console.log(utils.isNode({})); //=> false
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @returns {Boolean}
+ * @api public
+ */
+
+utils.isNode = function(node) {
+  return typeOf(node) === 'object' && node.isNode === true;
+};
+
+/**
+ * Emit an empty string for the given `node`.
+ *
+ * ```js
+ * // do nothing for beginning-of-string
+ * snapdragon.compiler.set('bos', utils.noop);
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @returns {undefined}
+ * @api public
+ */
+
+utils.noop = function(node) {
+  append(this, '', node);
+};
+
+/**
+ * Appdend `node.val` to `compiler.output`, exactly as it was created
+ * by the parser.
+ *
+ * ```js
+ * snapdragon.compiler.set('text', utils.identity);
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @returns {undefined}
+ * @api public
+ */
+
+utils.identity = function(node) {
+  append(this, node.val, node);
+};
+
+/**
+ * Previously named `.emit`, this method appends the given `val`
+ * to `compiler.output` for the given node. Useful when you know
+ * what value should be appended advance, regardless of the actual
+ * value of `node.val`.
+ *
+ * ```js
+ * snapdragon.compiler
+ *   .set('i', function(node) {
+ *     this.mapVisit(node);
+ *   })
+ *   .set('i.open', utils.append('<i>'))
+ *   .set('i.close', utils.append('</i>'))
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @returns {Function} Returns a compiler middleware function.
+ * @api public
+ */
+
+utils.append = function(val) {
+  return function(node) {
+    append(this, val, node);
+  };
+};
+
+/**
+ * Used in compiler middleware, this onverts an AST node into
+ * an empty `text` node and deletes `node.nodes` if it exists.
+ * The advantage of this method is that, as opposed to completely
+ * removing the node, indices will not need to be re-calculated
+ * in sibling nodes, and nothing is appended to the output.
+ *
+ * ```js
+ * utils.toNoop(node);
+ * // convert `node.nodes` to the given value instead of deleting it
+ * utils.toNoop(node, []);
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Array} `nodes` Optionally pass a new `nodes` value, to replace the existing `node.nodes` array.
+ * @api public
+ */
+
+utils.toNoop = function(node, nodes) {
+  if (nodes) {
+    node.nodes = nodes;
+  } else {
+    delete node.nodes;
+    node.type = 'text';
+    node.val = '';
+  }
+};
+
+/**
+ * Visit `node` with the given `fn`. The built-in `.visit` method in snapdragon
+ * automatically calls registered compilers, this allows you to pass a visitor
+ * function.
+ *
+ * ```js
+ * snapdragon.compiler.set('i', function(node) {
+ *   utils.visit(node, function(childNode) {
+ *     // do stuff with "childNode"
+ *     return childNode;
+ *   });
+ * });
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Function} `fn`
+ * @return {Object} returns the node after recursively visiting all child nodes.
+ * @api public
+ */
+
+utils.visit = function(node, fn) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isFunction(fn), 'expected a visitor function');
+  fn(node);
+  return node.nodes ? utils.mapVisit(node, fn) : node;
+};
+
+/**
+ * Map [visit](#visit) the given `fn` over `node.nodes`. This is called by
+ * [visit](#visit), use this method if you do not want `fn` to be called on
+ * the first node.
+ *
+ * ```js
+ * snapdragon.compiler.set('i', function(node) {
+ *   utils.mapVisit(node, function(childNode) {
+ *     // do stuff with "childNode"
+ *     return childNode;
+ *   });
+ * });
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Object} `options`
+ * @param {Function} `fn`
+ * @return {Object} returns the node
+ * @api public
+ */
+
+utils.mapVisit = function(node, fn) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isArray(node.nodes), 'expected node.nodes to be an array');
+  assert(isFunction(fn), 'expected a visitor function');
+
+  for (var i = 0; i < node.nodes.length; i++) {
+    utils.visit(node.nodes[i], fn);
+  }
+  return node;
+};
+
+/**
+ * Unshift an `*.open` node onto `node.nodes`.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * snapdragon.parser.set('brace', function(node) {
+ *   var match = this.match(/^{/);
+ *   if (match) {
+ *     var parent = new Node({type: 'brace'});
+ *     utils.addOpen(parent, Node);
+ *     console.log(parent.nodes[0]):
+ *     // { type: 'brace.open', val: '' };
+ *
+ *     // push the parent "brace" node onto the stack
+ *     this.push(parent);
+ *
+ *     // return the parent node, so it's also added to the AST
+ *     return brace;
+ *   }
+ * });
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Function} `Node` (required) Node constructor function from [snapdragon-node][].
+ * @param {Function} `filter` Optionaly specify a filter function to exclude the node.
+ * @return {Object} Returns the created opening node.
+ * @api public
+ */
+
+utils.addOpen = function(node, Node, val, filter) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isFunction(Node), 'expected Node to be a constructor function');
+
+  if (typeof val === 'function') {
+    filter = val;
+    val = '';
+  }
+
+  if (typeof filter === 'function' && !filter(node)) return;
+  var open = new Node({ type: node.type + '.open', val: val});
+  var unshift = node.unshift || node.unshiftNode;
+  if (typeof unshift === 'function') {
+    unshift.call(node, open);
+  } else {
+    utils.unshiftNode(node, open);
+  }
+  return open;
+};
+
+/**
+ * Push a `*.close` node onto `node.nodes`.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * snapdragon.parser.set('brace', function(node) {
+ *   var match = this.match(/^}/);
+ *   if (match) {
+ *     var parent = this.parent();
+ *     if (parent.type !== 'brace') {
+ *       throw new Error('missing opening: ' + '}');
+ *     }
+ *
+ *     utils.addClose(parent, Node);
+ *     console.log(parent.nodes[parent.nodes.length - 1]):
+ *     // { type: 'brace.close', val: '' };
+ *
+ *     // no need to return a node, since the parent
+ *     // was already added to the AST
+ *     return;
+ *   }
+ * });
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Function} `Node` (required) Node constructor function from [snapdragon-node][].
+ * @param {Function} `filter` Optionaly specify a filter function to exclude the node.
+ * @return {Object} Returns the created closing node.
+ * @api public
+ */
+
+utils.addClose = function(node, Node, val, filter) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isFunction(Node), 'expected Node to be a constructor function');
+
+  if (typeof val === 'function') {
+    filter = val;
+    val = '';
+  }
+
+  if (typeof filter === 'function' && !filter(node)) return;
+  var close = new Node({ type: node.type + '.close', val: val});
+  var push = node.push || node.pushNode;
+  if (typeof push === 'function') {
+    push.call(node, close);
+  } else {
+    utils.pushNode(node, close);
+  }
+  return close;
+};
+
+/**
+ * Wraps the given `node` with `*.open` and `*.close` nodes.
+ *
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Function} `Node` (required) Node constructor function from [snapdragon-node][].
+ * @param {Function} `filter` Optionaly specify a filter function to exclude the node.
+ * @return {Object} Returns the node
+ * @api public
+ */
+
+utils.wrapNodes = function(node, Node, filter) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isFunction(Node), 'expected Node to be a constructor function');
+
+  utils.addOpen(node, Node, filter);
+  utils.addClose(node, Node, filter);
+  return node;
+};
+
+/**
+ * Push the given `node` onto `parent.nodes`, and set `parent` as `node.parent.
+ *
+ * ```js
+ * var parent = new Node({type: 'foo'});
+ * var node = new Node({type: 'bar'});
+ * utils.pushNode(parent, node);
+ * console.log(parent.nodes[0].type) // 'bar'
+ * console.log(node.parent.type) // 'foo'
+ * ```
+ * @param {Object} `parent`
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Object} Returns the child node
+ * @api public
+ */
+
+utils.pushNode = function(parent, node) {
+  assert(utils.isNode(parent), 'expected parent node to be an instance of Node');
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+
+  node.define('parent', parent);
+  parent.nodes = parent.nodes || [];
+  parent.nodes.push(node);
+  return node;
+};
+
+/**
+ * Unshift `node` onto `parent.nodes`, and set `parent` as `node.parent.
+ *
+ * ```js
+ * var parent = new Node({type: 'foo'});
+ * var node = new Node({type: 'bar'});
+ * utils.unshiftNode(parent, node);
+ * console.log(parent.nodes[0].type) // 'bar'
+ * console.log(node.parent.type) // 'foo'
+ * ```
+ * @param {Object} `parent`
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {undefined}
+ * @api public
+ */
+
+utils.unshiftNode = function(parent, node) {
+  assert(utils.isNode(parent), 'expected parent node to be an instance of Node');
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+
+  node.define('parent', parent);
+  parent.nodes = parent.nodes || [];
+  parent.nodes.unshift(node);
+};
+
+/**
+ * Pop the last `node` off of `parent.nodes`. The advantage of
+ * using this method is that it checks for `node.nodes` and works
+ * with any version of `snapdragon-node`.
+ *
+ * ```js
+ * var parent = new Node({type: 'foo'});
+ * utils.pushNode(parent, new Node({type: 'foo'}));
+ * utils.pushNode(parent, new Node({type: 'bar'}));
+ * utils.pushNode(parent, new Node({type: 'baz'}));
+ * console.log(parent.nodes.length); //=> 3
+ * utils.popNode(parent);
+ * console.log(parent.nodes.length); //=> 2
+ * ```
+ * @param {Object} `parent`
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Number|Undefined} Returns the length of `node.nodes` or undefined.
+ * @api public
+ */
+
+utils.popNode = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  if (typeof node.pop === 'function') {
+    return node.pop();
+  }
+  return node.nodes && node.nodes.pop();
+};
+
+/**
+ * Shift the first `node` off of `parent.nodes`. The advantage of
+ * using this method is that it checks for `node.nodes` and works
+ * with any version of `snapdragon-node`.
+ *
+ * ```js
+ * var parent = new Node({type: 'foo'});
+ * utils.pushNode(parent, new Node({type: 'foo'}));
+ * utils.pushNode(parent, new Node({type: 'bar'}));
+ * utils.pushNode(parent, new Node({type: 'baz'}));
+ * console.log(parent.nodes.length); //=> 3
+ * utils.shiftNode(parent);
+ * console.log(parent.nodes.length); //=> 2
+ * ```
+ * @param {Object} `parent`
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Number|Undefined} Returns the length of `node.nodes` or undefined.
+ * @api public
+ */
+
+utils.shiftNode = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  if (typeof node.shift === 'function') {
+    return node.shift();
+  }
+  return node.nodes && node.nodes.shift();
+};
+
+/**
+ * Remove the specified `node` from `parent.nodes`.
+ *
+ * ```js
+ * var parent = new Node({type: 'abc'});
+ * var foo = new Node({type: 'foo'});
+ * utils.pushNode(parent, foo);
+ * utils.pushNode(parent, new Node({type: 'bar'}));
+ * utils.pushNode(parent, new Node({type: 'baz'}));
+ * console.log(parent.nodes.length); //=> 3
+ * utils.removeNode(parent, foo);
+ * console.log(parent.nodes.length); //=> 2
+ * ```
+ * @param {Object} `parent`
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Object|undefined} Returns the removed node, if successful, or undefined if it does not exist on `parent.nodes`.
+ * @api public
+ */
+
+utils.removeNode = function(parent, node) {
+  assert(utils.isNode(parent), 'expected parent.node to be an instance of Node');
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+
+  if (!parent.nodes) {
+    return null;
+  }
+
+  if (typeof parent.remove === 'function') {
+    return parent.remove(node);
+  }
+
+  var idx = parent.nodes.indexOf(node);
+  if (idx !== -1) {
+    return parent.nodes.splice(idx, 1);
+  }
+};
+
+/**
+ * Returns true if `node.type` matches the given `type`. Throws a
+ * `TypeError` if `node` is not an instance of `Node`.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var node = new Node({type: 'foo'});
+ * console.log(utils.isType(node, 'foo')); // false
+ * console.log(utils.isType(node, 'bar')); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {String} `type`
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isType = function(node, type) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  switch (typeOf(type)) {
+    case 'array':
+      var types = type.slice();
+      for (var i = 0; i < types.length; i++) {
+        if (utils.isType(node, types[i])) {
+          return true;
+        }
+      }
+      return false;
+    case 'string':
+      return node.type === type;
+    case 'regexp':
+      return type.test(node.type);
+    default: {
+      throw new TypeError('expected "type" to be an array, string or regexp');
+    }
+  }
+};
+
+/**
+ * Returns true if the given `node` has the given `type` in `node.nodes`.
+ * Throws a `TypeError` if `node` is not an instance of `Node`.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var node = new Node({
+ *   type: 'foo',
+ *   nodes: [
+ *     new Node({type: 'bar'}),
+ *     new Node({type: 'baz'})
+ *   ]
+ * });
+ * console.log(utils.hasType(node, 'xyz')); // false
+ * console.log(utils.hasType(node, 'baz')); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {String} `type`
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.hasType = function(node, type) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  if (!Array.isArray(node.nodes)) return false;
+  for (var i = 0; i < node.nodes.length; i++) {
+    if (utils.isType(node.nodes[i], type)) {
+      return true;
+    }
+  }
+  return false;
+};
+
+/**
+ * Returns the first node from `node.nodes` of the given `type`
+ *
+ * ```js
+ * var node = new Node({
+ *   type: 'foo',
+ *   nodes: [
+ *     new Node({type: 'text', val: 'abc'}),
+ *     new Node({type: 'text', val: 'xyz'})
+ *   ]
+ * });
+ *
+ * var textNode = utils.firstOfType(node.nodes, 'text');
+ * console.log(textNode.val);
+ * //=> 'abc'
+ * ```
+ * @param {Array} `nodes`
+ * @param {String} `type`
+ * @return {Object|undefined} Returns the first matching node or undefined.
+ * @api public
+ */
+
+utils.firstOfType = function(nodes, type) {
+  for (var i = 0; i < nodes.length; i++) {
+    var node = nodes[i];
+    if (utils.isType(node, type)) {
+      return node;
+    }
+  }
+};
+
+/**
+ * Returns the node at the specified index, or the first node of the
+ * given `type` from `node.nodes`.
+ *
+ * ```js
+ * var node = new Node({
+ *   type: 'foo',
+ *   nodes: [
+ *     new Node({type: 'text', val: 'abc'}),
+ *     new Node({type: 'text', val: 'xyz'})
+ *   ]
+ * });
+ *
+ * var nodeOne = utils.findNode(node.nodes, 'text');
+ * console.log(nodeOne.val);
+ * //=> 'abc'
+ *
+ * var nodeTwo = utils.findNode(node.nodes, 1);
+ * console.log(nodeTwo.val);
+ * //=> 'xyz'
+ * ```
+ *
+ * @param {Array} `nodes`
+ * @param {String|Number} `type` Node type or index.
+ * @return {Object} Returns a node or undefined.
+ * @api public
+ */
+
+utils.findNode = function(nodes, type) {
+  if (!Array.isArray(nodes)) {
+    return null;
+  }
+  if (typeof type === 'number') {
+    return nodes[type];
+  }
+  return utils.firstOfType(nodes, type);
+};
+
+/**
+ * Returns true if the given node is an "*.open" node.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var brace = new Node({type: 'brace'});
+ * var open = new Node({type: 'brace.open'});
+ * var close = new Node({type: 'brace.close'});
+ *
+ * console.log(utils.isOpen(brace)); // false
+ * console.log(utils.isOpen(open)); // true
+ * console.log(utils.isOpen(close)); // false
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isOpen = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  return node.type.slice(-5) === '.open';
+};
+
+/**
+ * Returns true if the given node is a "*.close" node.
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var brace = new Node({type: 'brace'});
+ * var open = new Node({type: 'brace.open'});
+ * var close = new Node({type: 'brace.close'});
+ *
+ * console.log(utils.isClose(brace)); // false
+ * console.log(utils.isClose(open)); // false
+ * console.log(utils.isClose(close)); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isClose = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  return node.type.slice(-6) === '.close';
+};
+
+/**
+ * Returns true if `node.nodes` **has** an `.open` node
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var brace = new Node({
+ *   type: 'brace',
+ *   nodes: []
+ * });
+ *
+ * var open = new Node({type: 'brace.open'});
+ * console.log(utils.hasOpen(brace)); // false
+ *
+ * brace.pushNode(open);
+ * console.log(utils.hasOpen(brace)); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.hasOpen = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  var first = node.first || node.nodes ? node.nodes[0] : null;
+  if (utils.isNode(first)) {
+    return first.type === node.type + '.open';
+  }
+  return false;
+};
+
+/**
+ * Returns true if `node.nodes` **has** a `.close` node
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var brace = new Node({
+ *   type: 'brace',
+ *   nodes: []
+ * });
+ *
+ * var close = new Node({type: 'brace.close'});
+ * console.log(utils.hasClose(brace)); // false
+ *
+ * brace.pushNode(close);
+ * console.log(utils.hasClose(brace)); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.hasClose = function(node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  var last = node.last || node.nodes ? node.nodes[node.nodes.length - 1] : null;
+  if (utils.isNode(last)) {
+    return last.type === node.type + '.close';
+  }
+  return false;
+};
+
+/**
+ * Returns true if `node.nodes` has both `.open` and `.close` nodes
+ *
+ * ```js
+ * var Node = require('snapdragon-node');
+ * var brace = new Node({
+ *   type: 'brace',
+ *   nodes: []
+ * });
+ *
+ * var open = new Node({type: 'brace.open'});
+ * var close = new Node({type: 'brace.close'});
+ * console.log(utils.hasOpen(brace)); // false
+ * console.log(utils.hasClose(brace)); // false
+ *
+ * brace.pushNode(open);
+ * brace.pushNode(close);
+ * console.log(utils.hasOpen(brace)); // true
+ * console.log(utils.hasClose(brace)); // true
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.hasOpenAndClose = function(node) {
+  return utils.hasOpen(node) && utils.hasClose(node);
+};
+
+/**
+ * Push the given `node` onto the `state.inside` array for the
+ * given type. This array is used as a specialized "stack" for
+ * only the given `node.type`.
+ *
+ * ```js
+ * var state = { inside: {}};
+ * var node = new Node({type: 'brace'});
+ * utils.addType(state, node);
+ * console.log(state.inside);
+ * //=> { brace: [{type: 'brace'}] }
+ * ```
+ * @param {Object} `state` The `compiler.state` object or custom state object.
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Array} Returns the `state.inside` stack for the given type.
+ * @api public
+ */
+
+utils.addType = function(state, node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isObject(state), 'expected state to be an object');
+
+  var type = node.parent
+    ? node.parent.type
+    : node.type.replace(/\.open$/, '');
+
+  if (!state.hasOwnProperty('inside')) {
+    state.inside = {};
+  }
+  if (!state.inside.hasOwnProperty(type)) {
+    state.inside[type] = [];
+  }
+
+  var arr = state.inside[type];
+  arr.push(node);
+  return arr;
+};
+
+/**
+ * Remove the given `node` from the `state.inside` array for the
+ * given type. This array is used as a specialized "stack" for
+ * only the given `node.type`.
+ *
+ * ```js
+ * var state = { inside: {}};
+ * var node = new Node({type: 'brace'});
+ * utils.addType(state, node);
+ * console.log(state.inside);
+ * //=> { brace: [{type: 'brace'}] }
+ * utils.removeType(state, node);
+ * //=> { brace: [] }
+ * ```
+ * @param {Object} `state` The `compiler.state` object or custom state object.
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @return {Array} Returns the `state.inside` stack for the given type.
+ * @api public
+ */
+
+utils.removeType = function(state, node) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isObject(state), 'expected state to be an object');
+
+  var type = node.parent
+    ? node.parent.type
+    : node.type.replace(/\.close$/, '');
+
+  if (state.inside.hasOwnProperty(type)) {
+    return state.inside[type].pop();
+  }
+};
+
+/**
+ * Returns true if `node.val` is an empty string, or `node.nodes` does
+ * not contain any non-empty text nodes.
+ *
+ * ```js
+ * var node = new Node({type: 'text'});
+ * utils.isEmpty(node); //=> true
+ * node.val = 'foo';
+ * utils.isEmpty(node); //=> false
+ * ```
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {Function} `fn`
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isEmpty = function(node, fn) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+
+  if (!Array.isArray(node.nodes)) {
+    if (node.type !== 'text') {
+      return true;
+    }
+    if (typeof fn === 'function') {
+      return fn(node, node.parent);
+    }
+    return !utils.trim(node.val);
+  }
+
+  for (var i = 0; i < node.nodes.length; i++) {
+    var child = node.nodes[i];
+    if (utils.isOpen(child) || utils.isClose(child)) {
+      continue;
+    }
+    if (!utils.isEmpty(child, fn)) {
+      return false;
+    }
+  }
+
+  return true;
+};
+
+/**
+ * Returns true if the `state.inside` stack for the given type exists
+ * and has one or more nodes on it.
+ *
+ * ```js
+ * var state = { inside: {}};
+ * var node = new Node({type: 'brace'});
+ * console.log(utils.isInsideType(state, 'brace')); //=> false
+ * utils.addType(state, node);
+ * console.log(utils.isInsideType(state, 'brace')); //=> true
+ * utils.removeType(state, node);
+ * console.log(utils.isInsideType(state, 'brace')); //=> false
+ * ```
+ * @param {Object} `state`
+ * @param {String} `type`
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isInsideType = function(state, type) {
+  assert(isObject(state), 'expected state to be an object');
+  assert(isString(type), 'expected type to be a string');
+
+  if (!state.hasOwnProperty('inside')) {
+    return false;
+  }
+
+  if (!state.inside.hasOwnProperty(type)) {
+    return false;
+  }
+
+  return state.inside[type].length > 0;
+};
+
+/**
+ * Returns true if `node` is either a child or grand-child of the given `type`,
+ * or `state.inside[type]` is a non-empty array.
+ *
+ * ```js
+ * var state = { inside: {}};
+ * var node = new Node({type: 'brace'});
+ * var open = new Node({type: 'brace.open'});
+ * console.log(utils.isInside(state, open, 'brace')); //=> false
+ * utils.pushNode(node, open);
+ * console.log(utils.isInside(state, open, 'brace')); //=> true
+ * ```
+ * @param {Object} `state` Either the `compiler.state` object, if it exists, or a user-supplied state object.
+ * @param {Object} `node` Instance of [snapdragon-node][]
+ * @param {String} `type` The `node.type` to check for.
+ * @return {Boolean}
+ * @api public
+ */
+
+utils.isInside = function(state, node, type) {
+  assert(utils.isNode(node), 'expected node to be an instance of Node');
+  assert(isObject(state), 'expected state to be an object');
+
+  if (Array.isArray(type)) {
+    for (var i = 0; i < type.length; i++) {
+      if (utils.isInside(state, node, type[i])) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  var parent = node.parent;
+  if (typeof type === 'string') {
+    return (parent && parent.type === type) || utils.isInsideType(state, type);
+  }
+
+  if (typeOf(type) === 'regexp') {
+    if (parent && parent.type && type.test(parent.type)) {
+      return true;
+    }
+
+    var keys = Object.keys(state.inside);
+    var len = keys.length;
+    var idx = -1;
+    while (++idx < len) {
+      var key = keys[idx];
+      var val = state.inside[key];
+
+      if (Array.isArray(val) && val.length !== 0 && type.test(key)) {
+        return true;
+      }
+    }
+  }
+  return false;
+};
+
+/**
+ * Get the last `n` element from the given `array`. Used for getting
+ * a node from `node.nodes.`
+ *
+ * @param {Array} `array`
+ * @param {Number} `n`
+ * @return {undefined}
+ * @api public
+ */
+
+utils.last = function(arr, n) {
+  return arr[arr.length - (n || 1)];
+};
+
+/**
+ * Cast the given `val` to an array.
+ *
+ * ```js
+ * console.log(utils.arrayify(''));
+ * //=> []
+ * console.log(utils.arrayify('foo'));
+ * //=> ['foo']
+ * console.log(utils.arrayify(['foo']));
+ * //=> ['foo']
+ * ```
+ * @param {any} `val`
+ * @return {Array}
+ * @api public
+ */
+
+utils.arrayify = function(val) {
+  if (typeof val === 'string' && val !== '') {
+    return [val];
+  }
+  if (!Array.isArray(val)) {
+    return [];
+  }
+  return val;
+};
+
+/**
+ * Convert the given `val` to a string by joining with `,`. Useful
+ * for creating a cheerio/CSS/DOM-style selector from a list of strings.
+ *
+ * @param {any} `val`
+ * @return {Array}
+ * @api public
+ */
+
+utils.stringify = function(val) {
+  return utils.arrayify(val).join(',');
+};
+
+/**
+ * Ensure that the given value is a string and call `.trim()` on it,
+ * or return an empty string.
+ *
+ * @param {String} `str`
+ * @return {String}
+ * @api public
+ */
+
+utils.trim = function(str) {
+  return typeof str === 'string' ? str.trim() : '';
+};
+
+/**
+ * Return true if val is an object
+ */
+
+function isObject(val) {
+  return typeOf(val) === 'object';
+}
+
+/**
+ * Return true if val is a string
+ */
+
+function isString(val) {
+  return typeof val === 'string';
+}
+
+/**
+ * Return true if val is a function
+ */
+
+function isFunction(val) {
+  return typeof val === 'function';
+}
+
+/**
+ * Return true if val is an array
+ */
+
+function isArray(val) {
+  return Array.isArray(val);
+}
+
+/**
+ * Shim to ensure the `.append` methods work with any version of snapdragon
+ */
+
+function append(compiler, val, node) {
+  if (typeof compiler.append !== 'function') {
+    return compiler.emit(val, node);
+  }
+  return compiler.append(val, node);
+}
+
+/**
+ * Simplified assertion. Throws an error is `val` is falsey.
+ */
+
+function assert(val, message) {
+  if (!val) throw new Error(message);
+}