[ec_date.erl] Redundant parse() clauses

[l3kn]

The parse clauses

parse([Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms | PAM], _Now, _Opts)
  when ?is_meridian(PAM) andalso
       (?is_us_sep(X) orelse ?is_world_sep(X))
       andalso ?is_year(Year) ->
    {{Year, Month, Day}, {hour(Hour, PAM), Min, Sec}, {Ms}};

and

parse([Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms], _Now, _Opts)
  when  (?is_us_sep(X) orelse ?is_world_sep(X))
        andalso ?is_year(Year) ->
    {{Year, Month, Day}, {hour(Hour,[]), Min, Sec}, {Ms}};

in the file ec_date.erl (lines 155 to 178) seem to be equivalent, since they both match lists without a value for PAM.

6> [Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms | PAM] = [2014,$-,8,$-,28,23,$:,39,$:,10,$.,1].   
[2014,45,8,45,28,23,58,39,58,10,46,1]
7> PAM.
[]
8> [Year,X,Month,X,Day,Hour,$:,Min,$:,Sec,$., Ms] = [2014,$-,8,$-,28,23,$:,39,$:,10,$.,1].
[2014,45,8,45,28,23,58,39,58,10,46,1]

In the first case PAM is set to [] which would pass the ?is_meridian(PAM) guard

-define( is_meridian(X), (X==[] orelse X==[am] orelse X==[pm]) ).

and result in hour(Hour, PAM) being equivalent to hour(Hour, []).

This affects the four clauses below (lines 173, 176, 184, 187), too. The only difference is that
in this case the first two clauses use the ?is_year(Year) guard and the latter two ?is_month(Month).

Note: I am not too familiar with Erlang and might be missing something.