Couldn't find the language specification anywhere, it basically the Nix source? The repo's README refers to the Nix manual, but it seems incomplete. For example
power-bi-angular
tomcat6
ronin
lightning
amazon-device-messaging
theme-customizer
iproute
hdf5
lightningchart
mo-cap
linguistics
go-github
filetime
file-manager
listener
make-shared
toast-ui-editor
access-specifier
pass-by-rvalue-reference
tcheckbox
boot2docker
session-reuse
srp-protocol
fragmentstateadapter
react-chartjs
pdf-generation
ln
duckduckgo
prometheus-python-client
rserve