Merge pull request #5 from mjeronimo/mjeronimo/add-block-comment

A couple more doc fixes from review comments

rclcpp/include/rclcpp/parameter_event_handler.hpp

@@ -59,19 +59,21 @@ struct ParameterEventCallbackHandle
 /// A class used to "handle" (monitor and respond to) changes to parameters.
 /**
  * The ParameterEventHandler class allows for the monitoring of changes to node parameters,
- * either a node's own parameters or parameters owned by other nodes in the system. Multiple
- * parameter callbacks can be set and will be invoked when the specified parameter changes.
+ * either a node's own parameters or parameters owned by other nodes in the system.
+ * Multiple parameter callbacks can be set and will be invoked when the specified parameter
+ * changes.
  *
- * The first step is to instance a ParameterEventHandler, providing a ROS node to use
- * to create any required subscriptions.
+ * The first step is to instantiate a ParameterEventHandler, providing a ROS node to use
+ * to create any required subscriptions:
  *
  *   auto param_handler = std::make_shared<rclcpp::ParameterEventHandler>(node);
  *
  * Next, you can supply a callback to the add_parameter_callback method, as follows:
  *
  *   auto cb1 = [&node](const rclcpp::Parameter & p) {
  *      RCLCPP_INFO(
- *        node->get_logger(), "cb1: Received an update to parameter \"%s\" of type %s: \"%ld\"",
+ *        node->get_logger(),
+ *        "cb1: Received an update to parameter \"%s\" of type %s: \"%ld\"",
  *        p.get_name().c_str(),
  *        p.get_type_name().c_str(),
  *        p.as_int());
@@ -80,15 +82,16 @@ struct ParameterEventCallbackHandle
  *
  * In this case, we didn't supply a node name (the third, optional, parameter) so the
  * default will be to monitor for changes to the "an_int_param" parameter associated with
- * the ROS node supplied in the ParameterEventHandler constructor. The callback, a lambda
- * function in this case, simply prints out the value of the parameter.
+ * the ROS node supplied in the ParameterEventHandler constructor.
+ * The callback, a lambda function in this case, simply prints out the value of the parameter.
  *
  * You may also monitor for changes to parameters in other nodes by supplying the node
  * name to add_parameter_callback:
  *
  *   auto cb2 = [&node](const rclcpp::Parameter & p) {
  *       RCLCPP_INFO(
- *         node->get_logger(), "cb2: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *         node->get_logger(),
+ *         "cb2: Received an update to parameter \"%s\" of type: %s: \"%s\"",
  *         p.get_name().c_str(),
  *         p.get_type_name().c_str(),
  *         p.as_string().c_str());
@@ -104,15 +107,16 @@ struct ParameterEventCallbackHandle
  *
  *   param_handler->remove_parameter_callback(handle2);
  *
- * You can also monitor for *all* parameter changes, using add_parameter_event_callback. In this
- * case, the callback will be invoked whenever any parameter changes in the system. You are likely
- * interested in a subset of these parameter changes, so in the callback it is convenient to use
- * a regular expression on the node names or namespaces of interest. For example,
+ * You can also monitor for *all* parameter changes, using add_parameter_event_callback.
+ * In this case, the callback will be invoked whenever any parameter changes in the system.
+ * You are likely interested in a subset of these parameter changes, so in the callback it
+ * is convenient to use a regular expression on the node names or namespaces of interest.
+ * For example:
  *
  *   auto cb3 =
  *     [fqn, remote_param_name, &node](const rcl_interfaces::msg::ParameterEvent::SharedPtr & event) {
  *       // Look for any updates to parameters in "/a_namespace" as well as any parameter changes
- *       // to our own node ("this_node").
+ *       // to our own node ("this_node")
  *       std::regex re("(/a_namespace/.*)|(/this_node)");
  *       if (regex_match(event->node, re)) {
  *         // Now that we know the event matches the regular expression we scanned for, we can
@@ -122,7 +126,8 @@ struct ParameterEventCallbackHandle
  *             *event, p, remote_param_name, fqn))
  *         {
  *           RCLCPP_INFO(
- *             node->get_logger(), "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *             node->get_logger(),
+ *             "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
  *             p.get_name().c_str(),
  *             p.get_type_name().c_str(),
  *             p.as_string().c_str());
@@ -133,7 +138,8 @@ struct ParameterEventCallbackHandle
  *         auto params = rclcpp::ParameterEventsSubscriber::get_parameters_from_event(*event);
  *         for (auto & p : params) {
  *           RCLCPP_INFO(
- *             node->get_logger(), "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *             node->get_logger(),
+ *             "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
  *             p.get_name().c_str(),
  *             p.get_type_name().c_str(),
  *             p.value_to_string().c_str());
@@ -145,7 +151,7 @@ struct ParameterEventCallbackHandle
  * For both parameter callbacks and parameter event callbacks, when multiple callbacks are added,
  * the callbacks are invoked last-in, first-called order (LIFO).
  *
- * To remove a parameter event callback, use
+ * To remove a parameter event callback, use:
  *
  *   param_handler->remove_event_parameter_callback(handle);
  */