arpunk / memento

Mnesia wrapper for LFE

Memento

Introduction

Memento is an mnesia wrapper for LFE

Installation

Just add it to your rebar.config deps:

{deps, [
 ...
 {memento, {git, "[email protected]:arpunk/memento.git", {branch, "master"}}}
 ...
]}.

And then do the usual:

$ rebar3 compile

Usage

It’s very easy!

(defmodule testing-memento
  (import
    (from memento-table (write 2))
    (from memento-query (select 2))))

(include-lib "memento/include/table.lfe")
(include-lib "memento/include/transaction.lfe")

;; First time?
(memento:stop)
(memento-schema:create)
(memento:start)

;; Let's define some records
(defrecord person
  name
  age)

;; Now let's define our table properties
(set person-opts `[#(type set)
                   #(disc_copies [,(node)])])

;; Once we are ready we can create the table
(create-table person person-opts)

;; And the fun starts
(with-transaction
  (write 'person (make-person name "John Doe" age 31)))

;; Querying
(with-transaction
  (select 'person
          (match-spec
            (((tuple _ name age)) (when (> age 20))
              (tuple 'ok name)))))