$ npm install webidl-grammar-post-processorPost-processor for WebIDL's grammar.
$ npm install webidl-grammar-post-processor
$ pp-webidl --input [string] --output [string]
--help Show help [boolean]
--version Show version number [boolean]
--input, -i Path to input file [required]
--output, -o Path to output file. Defaults to overwriting input