@spec all(String.t(), non_neg_integer()) ::
  {:ok, [DateTime.t()]} | {:error, String.t()}

Given a RRule, return occurrences until a limit is reached

Note Maximum occurrences is limited to 65,535 to avoid order to prevent infinite loops

@spec all_between(String.t(), DateTime.t(), DateTime.t()) ::
  {:ok, {[DateTime.t()], boolean()}} | {:error, String.t()}

Given a RRule, return all occurrences between the given UTC DateTimes.

In the success case, the return will be {:ok, {occurrences, has_more }}. The has_more boolean is used to inform you if there are more occurrences that weren't returned due to the limits. Generally you'll only care about the occurrences

Note Maximum occurrences is limited to 65,535 to avoid order to prevent infinite loops

Example

iex> RRule.all_between("DTSTART:20120101T093000Z\nRRULE:FREQ=DAILY;COUNT=5", ~U[2012-01-01 09:00:00Z], ~U[2012-02-01 09:00:00Z])
{:ok,
{[~U[2012-01-01 09:30:00Z], ~U[2012-01-02 09:30:00Z], ~U[2012-01-03 09:30:00Z],
~U[2012-01-04 09:30:00Z], ~U[2012-01-05 09:30:00Z]], false}}

@spec all_between(String.t(), DateTime.t(), DateTime.t(), integer()) ::
  {:ok, {[DateTime.t()], boolean()}} | {:error, String.t()}

Given a RRule, return n occurrences between the given UTC DateTimes, where n is the limit

Note Limit cannot be greater than 65,535

@spec get_start_date(String.t()) :: {:ok, DateTime.t()} | {:error, String.t()}

Given a RRule string, return the UTC DateTime when the rule starts

Example

iex> RRule.get_start_date("DTSTART:20120101T093000Z\nRRULE:FREQ=DAILY;COUNT=5")
{:ok, ~U[2012-01-01 09:30:00Z]}

@spec parse(String.t()) :: String.t()

Given a RRule, returns the expanded representation if parsed successfully

Example

iex> RRule.parse("DTSTART:20120101T093000Z\nRRULE:FREQ=DAILY;COUNT=5")
{:ok, "DTSTART:20120101T093000Z\nRRULE:FREQ=DAILY;COUNT=5;BYHOUR=9;BYMINUTE=30;BYSECOND=0"}

@spec validate(String.t()) :: :ok | {:error, String.t()}

Given a RRule, return a boolean indicating if the rule is valid

iex> RRule.validate( "DTSTART:20120101T093000Z\nRRULE:FREQ=DAILY;COUNT=5")
:ok

iex> RRule.validate( "DTSTART:20120101T0930Z\nRRULE:FREQ=DAILY;COUNT=5")
{:error,
"RRule parsing error: `20120101T0930Z` is not a valid datetime format for `DTSTART`."}