Type aliases - pf-lang/pipefish GitHub Wiki
Type aliases are constructed in the newtype section, as you would expect, and take the form ` = alias , e.g:
newtype
ℤ = alias int
Strings = alias list{string}
These will alias both the types and their constructors, e.g. ℤ("42") means the same as int("42"); or Strings["fee", "fie", "fo", "fum"] means the same as list{string}["fee", "fie", "fo", "fum"].