CODEWITHSUNDEEP
erlangrecord
Marcin Majewski
Marcin Majewski

Reputation: 1047

Error in erlang when using records

I have created a simple program that should simulate an address book:

%% API
-export([]).
-export([createAddressBook/0]).
-export([checkIfExist/3]).
-export([addContact/3]).
-record(entry,{nameAndSurname,n_phone,email}).

createAddressBook() ->
  Test = #entry{nameAndSurname = {"Marcin", "Majewski"}, n_phone = [997], email=["[email protected]"]},
  [Test].

checkIfExist(_,_,[]) -> false;
checkIfExist(Name,Surname,[H|L]) ->
  if
    H#entry.nameAndSurname == {Name,Surname} -> true;
    true -> checkIfExist(Name,Surname,L)
  end.

addContact(Name,Surname,L)->
  case checkIfExist(Name,Surname,L) of
    true -> io:format("Entry already exist, nothing was created!");
    _ -> newEntry = #entry{nameAndSurname = {Name,Surname}, n_phone = [],email = []},lists:append(L,newEntry)
  end.

But when I invoke:

X=module_name:createAddressBook().
B=module_name:addContact("Name","Surname",X).

I am getting an error:

** exception error: no match of right hand side value 
{entry,{"Name","Surname"},[],[]}
in function addContact

I do not understand what causes this problem.

Upvotes: 0

Views: 78

Answers (1)

Viacheslav Kovalev
Viacheslav Kovalev

Reputation: 1745

You are tryin to assign record to atom:

newEntry = #entry{nameAndSurname = {Name,Surname}, n_phone = [],email = []},lists:append(L,newEntry)

Since newEntry starts from lowercase letter, erlang treats it as atom, but not variable. Just change it:

NewEntry = #entry{nameAndSurname = {Name,Surname}, n_phone = [],email]},
lists:append(L,NewEntry)

Upvotes: 2

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