IdentRelationAST allows us to reference a let binding in a relation (i.e.
IdentRelationAST allows us to reference a let binding in a relation (i.e. table) context. ExprF.IdentF allows us to reference a let binding in expression context. Ideally we can unify these two contexts, providing a single way to reference a let binding.
Can’t be a Map, because we need to arbitrarily transform the key
Represents the wildcard in a select projection For instance: "select foo.* from example" => ...(Splice(Some(Ident("foo"))))...
Represents the wildcard in a select projection For instance: "select foo.* from example" => ...(Splice(Some(Ident("foo"))))... "select * from example" => ...(Splice(None))...
Returns the name of the expression when viewed as a projection (of the optional relation), if available.