Types in records

Author: elbrujohalcon

README.md

@@ -43,6 +43,7 @@ Table of Contents:
     * [Records go first](#records-go-first)
     * [Don't share your records](#dont-share-your-records)
     * [Avoid records in specs](#avoid-records-in-specs)
+    * [Types in records](#types-in-records)
   * [Misc](#misc)
     * [Write function specs](#write-function-specs)
     * [Use -callback attributes over behaviour_info/1](use--callback-attributes-over-behaviour_info1)
@@ -333,6 +334,14 @@ Erlang syntax is horrible amirite? So you might as well make the best of it, rig
 
 *Reasoning*: Types can be exported, which aids documentation and, using ``opaque`` types it also helps with encapsulation and abstraction.
 
+***
+#####  Types in records
+> Always add type definitions to your record fields
+
+*Examples*: [record_types](src/record_types.erl)
+
+*Reasoning*: Records define data structures, and one of the most important parts of that definition is the type of the constituent pieces.
+
 ### Misc
 
 ***

src/col_width.erl

@@ -1,6 +1,6 @@
 -module(col_width).
 
--record(rec, {field1, field2, field3}).
+-record(rec, {field1 :: any(), field2 :: any(), field3 :: any()}).
 
 -export([bad/2, good/2]).
 

src/record_names.erl

@@ -3,9 +3,9 @@
 -export([records/0]).
 
 -record(badName, {}).
--record(bad_field_name, {badFieldName}).
--record('UPPERCASE', {'THIS_IS_BAD'}).
+-record(bad_field_name, {badFieldName :: any()}).
+-record('UPPERCASE', {'THIS_IS_BAD' :: any()}).
 
--record(good_name, {good_field_name}).
+-record(good_name, {good_field_name :: any()}).
 
 records() -> [#badName{}, #bad_field_name{}, #'UPPERCASE'{}, #good_name{}].

src/record_placement.erl

@@ -2,10 +2,16 @@
 
 -export([good/0, bad/0]).
 
--record(good, {this, record, appears, before, the_functions}).
+-record(good, { this_record   :: any()
+              , appears       :: any()
+              , before        :: any()
+              , the_functions :: any()}).
 
 good() -> [#good{}].
 
--record(bad, {this, record, appears, below, a_function}).
+-record(bad,  { this_record :: any()
+              , appears     :: any()
+              , below       :: any()
+              , a_function  :: any()}).
 
 bad() -> [#bad{}].

src/record_spec.erl

@@ -1,6 +1,6 @@
 -module(record_spec).
 
--record(state, {field1, field2}).
+-record(state, {field1:: any(), field2:: any()}).
 
 -opaque state() :: #state{}.
 

src/record_types.erl

@@ -0,0 +1,9 @@
+-module(record_types).
+
+-export([records/0]).
+
+-record(bad, {no_type}).
+
+-record(good, {with_type :: string()}).
+
+records() -> [#bad{}, #good{}].