The crux of the original parser--the data collected by Steve Souders over the years--has been extracted into a separate YAML file so as to be reusable as is by implementations in other programming languages.
ua-parser is just a small wrapper around this data.
Once setup, you can directly include the source file (UaParser.d) in your working directory or you can generate a library and add the path to dmd.conf.
Please refer to the example.d file. To run the example, execute the following command in terminal:
rdmd --force example.d