Distance function returns the distance (in meters) between two points of a given longitude and latitude relatively accurately (using a spherical approximation of the Earth) through the Haversin Distance Formula for great arc distance on a sphere with accuracy for small distances point coordinates are supplied in degrees and converted into rad.

NewClient returns a new Client.

NewSettingsFromYAML creates a new settings instance from a YAML config block.

NewWidget creates and returns an instance of Widget.

Client holds or configuration.

Item holds the interesting parts.

Settings defines the configuration properties for this module.

Widget is the container for your module's data.