I’d like to define a schema called
TwitterUsername and specify that it must be a string whose first character is the “@” symbol. Or I’d like to define a type called
format and specify that it’s a string but must be one of five pre-defined values. (surprised I can’t annotate with a
These are sort of weird value-type based operations and I am trying to suss out the boundaries of the existing type system as well as plans around it. Anyone messed around with this?