This function should strip any sanitization that has been applied to content within an iCal string.

iex> ICalendar.Util.Deserialize.desanitized(~s(lorem\\, ipsum))
"lorem, ipsum"

This function builds an rrule struct.

RRULE:FREQ=WEEKLY;WKST=SU;UNTIL=20201204T045959Z;INTERVAL=2;BYDAY=TH,WE;BYSETPOS=-1

will get turned into:

%{
  byday: ["TH", "WE"],
  freq: "WEEKLY",
  bysetpos: [-1],
  interval: 2,
  until: ~U[2020-12-04 04:59:59Z]
}

This function extracts the key and value parts from each line of a iCalendar string.

iex> ICalendar.Util.Deserialize.retrieve_kvs("lorem:ipsum")
%ICalendar.Property{key: "LOREM", params: %{}, value: "ipsum"}

This function extracts parameter data from a key in an iCalendar string.

iex> ICalendar.Util.Deserialize.retrieve_params(
...>   "DTSTART;TZID=America/Chicago")
["DTSTART", %{"TZID" => "America/Chicago"}]

It should be able to handle multiple parameters per key:

iex> ICalendar.Util.Deserialize.retrieve_params(
...>   "KEY;LOREM=ipsum;DOLOR=sit")
["KEY", %{"LOREM" => "ipsum", "DOLOR" => "sit"}]

This function is designed to parse iCal datetime strings into erlang dates.

It should be able to handle dates from the past:

iex> {:ok, date} = ICalendar.Util.Deserialize.to_date("19930407T153022Z")
...> Timex.to_erl(date)
{{1993, 4, 7}, {15, 30, 22}}

As well as the future:

iex> {:ok, date} = ICalendar.Util.Deserialize.to_date("39930407T153022Z")
...> Timex.to_erl(date)
{{3993, 4, 7}, {15, 30, 22}}

And should return error for incorrect dates:

iex> ICalendar.Util.Deserialize.to_date("1993/04/07")
{:error, "Expected `2 digit month` at line 1, column 5."}

It should handle timezones from the Olson Database:

iex> {:ok, date} = ICalendar.Util.Deserialize.to_date("19980119T020000",
...> %{"TZID" => "America/Chicago"})
...> [Timex.to_erl(date), date.time_zone]
[{{1998, 1, 19}, {2, 0, 0}}, "America/Chicago"]