Homeworks which was completed while I was being intern.

HOMEWORK I

Tasks:

1. Write module bool.erl and define dunctions b_not/1, b_and/2, b or/2 и b_nand/2 on atoms true and false.
2. Write a function, that return list like [ 1, 2,..., N -1, N ]. Example: [1,2,3] = create(3).
3. Write a function, that return reversed list like [N, N-1, ..., 1]. Example: [3,2,1] = reverse_create(3).
4. Write a function that print numbers in range [1, N].
5. Write a function that print odd numbers in range [1, N].
6. Write a module db.erl for key-value database. Using functions from module lists is not allowed. Interface: db:new() => Db. db:destroy(Db) => ok. db:write(Key, Element, Db) => NewDb. db:delete(Key, Db) => NewDb. db:read(Key, Db) => {ok, Element} | {error, instance}. db:match(Element, Db) => [Keyl, ..., KeyN].
7. Write a function, that return list's elements which are less or equal then number. Example: [1,2,3] = filter([1,2,3,4,5], 3).
8. Write a function that reverse list: [3,2,1] = reverse([1,2,3]).
9. Write a function that receive list of lists as argument and return their concatenation. Example: [1,2,3,4,five] = concatenate([[1,2,3], [], [4,five]]).
10. Write function flatten. Example: [1,2,3,4,5,6] = flatten([[1, [2, [3], []]], [[[4]]], [5,6]]).
11. Write a computer of ariphmetic's expressions.

11.1. Write a parser. Parser receive string and return parsed expression. For example, {minus, {plus, {num, 2}, {num, 3}}, {num, 4}} = parse("((2 + 3)-4)").

11.2. Write a computer. Computer compute value of parsed expressions.

11.3. Write a printer. Printer print parsed expression to the screen.

11.4. Write a simplyfier. It simplify parsed expressions. For example, {num, 2} = simplify({plus, {num, 2}, {num, 0}}).

11.5. Write a compiler. Compiler transform parsed expression to the actions of stack-based machine.

11.6. Write a simulator. Simulator execute result of compiling.

11.7. Append if expessions.

Result:

Task	File
1	modules/bool.erl
2,3	modules/create_list.erl
4,5	modules/print_num.erl
6	modules/db.erl
7,8,9,10	modules/list.erl
11	modules/calc.erl

HOMEWORK II

Tasks:

1. Change code of database from previous homework. Database must work in separated process. The function write must return tuple {error, Reason} if process died.
2. Create ring of processess. Some sent message must move through ring M times.
3. Create graph of processes and implement finding of connected component on this graph.
4. Create a lottery between processes. The processes must select one "best of the best" process.

Result:

Task	File
1	modules/db.erl
2	modules/process_ring.erl
3	modules/process_graph.erl
4	modules/process_game.erl

HOMEWORK III

Task:

1. Create your own supervisor.

Result:

1. modules/mysupervisor.erl

LAZY LISTS

Task:

1. Create any lazy list.

Result:

1. modules/lazy_fib.erl

HOMEWORK IV (monday 16.01.2017)

Tasks:

1. Implement pattern observer with interface: add_handler(Observer, Event, Callback). fire(Observer, Event).
2. Test it on some example.
3. Do same things with gen_event.

Result:

Task	File
1	modules/observer.erl
2	modules/mouse_observer.erl,modules/mouse.erl,modules/mouse_test.erl
3	modules/mouse_observer2.erl,modules/mouse_test.erl

HOMEWORK V

Task:

1. Rewrite database module with gen_server.
2. Implement supervisor for database using behaviour supervisor.
3. Create application using behaviour application.

Result:

1. apps/db.

HOMEWORK VI

Task:

1. Rewrite database module with ets tables instead of lists.

Result:

1. apps/db.

FINAL PROJECT

Task:

1. Create REST API for database.

Result:

1. apps/http_db