lambda-parser Installation $ nvm use && npm ci Testing $ npm test Debug $ npm run debug Play around https://omrelli.ug/nearley-playground/ Note, you'll need to remove the line with @preprocessor esmodule from the grammar when loading it into the playground. Generate railroad $ npm run railroad View railroad http://htmlpreview.github.io/?https://github.com/neo4j-devtools/lambda-parser/blob/master/railroad.html