_oasis

OASISFormat:  0.4
OCamlVersion: >= 4.02.0
Name:         phonedb
Version:      0.1
Maintainers:  test
Homepage:     test
Synopsis:     Some short description
Authors:      hathlesstroubles@gmail.com
License:      BSD-3-clause
Plugins:      META (0.4), DevFiles (0.4)
AlphaFeatures: ocamlbuild_more_args

Description:
  Some cool description

# This is a comment and this below creates an binary program    
Executable phonedb
  Path: src
  BuildTools:ocamlbuild
  install: true
  MainIs: phonedb.ml
  CompiledObject: native

Executable "test_phonedb"
  Path: test
  BuildTools:ocamlbuild
  install: false
  Build$: flag(tests)
  MainIs: phonedb_test.ml
  CompiledObject: native
  BuildDepends: oUnit

Test "test_phonedb"
  Run$: flag(tests)
  TestTools: test_phonedb
  Command: $test_phonedb
  WorkingDirectory: test

phonedb.ml

(* A phone number is a sequence of four integers. *)
type phone_number = int * int * int * int;;

(* A contact has a name and a phone number. *)
type contact = {
  name         : string;
  phone_number : phone_number
};;

(* Here is a dumb contact. *)
let nobody = { name = ""; phone_number = (0, 0, 0, 0) };;

(* A database is a collection of contacts. *)
type database = {
  number_of_contacts : int;
  contacts : contact array;
};;

(* [make n] is the database with no contact and at most [n] contacts
    stored inside. *)
let make max_number_of_contacts =
  {
    number_of_contacts = 0;
    contacts = Array.make max_number_of_contacts nobody
  };;

(* Queries are represented by a code and a contact.
   - If the code is 0 then the contact must be inserted.
   - If the code is 1 then the contact must be deleted.
   - If the code is 2 then we are looking for a contact
     with the same name in the database. *)
type query = {
  code    : int;
  contact : contact;
}

let search db contact =
  let rec aux idx =
    if idx >= db.number_of_contacts then
      (false, db, nobody)
    else if db.contacts.(idx).name = contact.name then
      (true, db, db.contacts.(idx))
    else
      aux (idx + 1)
  in
  aux 0;;

let insert db contact =
    if db.number_of_contacts >= Array.length db.contacts then
        (false, db, nobody)
    else
        let (status, db, _) = search db contact in
        if status then (false, db, contact) else
            let cells i =
                if i = db.number_of_contacts then contact else db.contacts.(i)
        in
      let db' = {
          number_of_contacts = db.number_of_contacts + 1;
          contacts = Array.init (Array.length db.contacts) cells
        }
        in
      (true, db', contact);;

let delete db contact =
  let (status, db, contact) = search db contact in
  if not status then (false, db, contact)
  else
    let cells i =
      if db.contacts.(i).name = contact.name then
        nobody
      else
        db.contacts.(i) in
    let db' = {
        number_of_contacts = db.number_of_contacts - 1;
        contacts = Array.init (Array.length db.contacts) cells
      }
    in
    (true, db', contact);;

(* Engine parses and interprets the query. *)
let engine db { code ; contact } =
  if code = 0 then insert db contact
  else if code = 1 then delete db contact
  else if code = 2 then search db contact
  else (false, db, nobody);;

phonedb_test.ml

(* A phone number is a sequence of four integers. *)
type phone_number = int * int * int * int;;

(* A contact has a name and a phone number. *)
type contact = {
  name         : string;
  phone_number : phone_number
};;

(* Here is a dumb contact. *)
let nobody = { name = ""; phone_number = (0, 0, 0, 0) };;

(* A database is a collection of contacts. *)
type database = {
  number_of_contacts : int;
  contacts : contact array;
};;

(* [make n] is the database with no contact and at most [n] contacts
    stored inside. *)
let make max_number_of_contacts =
  {
    number_of_contacts = 0;
    contacts = Array.make max_number_of_contacts nobody
  };;

(* Queries are represented by a code and a contact.
   - If the code is 0 then the contact must be inserted.
   - If the code is 1 then the contact must be deleted.
   - If the code is 2 then we are looking for a contact
     with the same name in the database. *)
type query = {
  code    : int;
  contact : contact;
}

let search db contact =
  let rec aux idx =
    if idx >= db.number_of_contacts then
      (false, db, nobody)
    else if db.contacts.(idx).name = contact.name then
      (true, db, db.contacts.(idx))
    else
      aux (idx + 1)
  in
  aux 0;;

let insert db contact =
    if db.number_of_contacts >= Array.length db.contacts then
        (false, db, nobody)
    else
        let (status, db, _) = search db contact in
        if status then (false, db, contact) else
            let cells i =
                if i = db.number_of_contacts then contact else db.contacts.(i)
        in
      let db' = {
          number_of_contacts = db.number_of_contacts + 1;
          contacts = Array.init (Array.length db.contacts) cells
        }
        in
      (true, db', contact);;

let delete db contact =
  let (status, db, contact) = search db contact in
  if not status then (false, db, contact)
  else
    let cells i =
      if db.contacts.(i).name = contact.name then
        nobody
      else
        db.contacts.(i) in
    let db' = {
        number_of_contacts = db.number_of_contacts - 1;
        contacts = Array.init (Array.length db.contacts) cells
      }
    in
    (true, db', contact);;

(* Engine parses and interprets the query. *)
let engine db { code ; contact } =
  if code = 0 then insert db contact
  else if code = 1 then delete db contact
  else if code = 2 then search db contact
  else (false, db, nobody);;