| title | File system interface |
|---|
Basic Types: integer, number, string, enumeration, symbol/key/UUID
String: finite array of code points
Enumerations: Month, Day of Week, CUSIP, State, ... (???define by regular exprssion)
Union/Sum type
Product type
Project, Restrict, Join(relational product)
Reduce(group by using monids)
Hierarchy as union type. union(a/b, a/c/d, ...)
$ ls
instrument
model
$ cd instrument
$ ls
bond
stock
futures
$ cd bond
$ ls
basic
municipal
treasury
$ ls basic
coupon
dated
maturity