blob: e17f7a50b687a97d8a04b59be31c4cc62fbc6a61 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
(** Schema: maps attribute names to domain/type names.
A schema defines the structure of a relation by listing each attribute
and its associated domain (type). This is used for:
- Hashing relations (schema is part of the relation identity)
- Validation (checking tuple membership)
- Persistence (storing and loading relations with their structure) *)
type t = (string * string) list
let empty : t = []
let add name domain_name (schema : t) : t =
(name, domain_name) :: schema
let attributes (schema : t) =
List.map fst schema
let to_string schema =
List.map (fun (n, t) -> n ^ ":" ^ t) schema
|> String.concat ","
|
