wojtekmach / calendar_interval Goto Github PK

They will take calendar_interval.first and return %Date{} and %Date.Range{} respectively.

https://travis-ci.org/wojtekmach/calendar_interval/jobs/606359078?utm_medium=notification&utm_source=email

Calendar.Interval.new/3 is currently a private function however it has valid public use cases where creating an interval between two arbitrary naive_date_times with a given precision is a requirement. Consider making it public?

It is sometimes convenient to find "next Monday" or "last Friday", I think we can neatly achieve it with this API:

# next Monday
iex> CalendarInterval.next(~I"2020-07-09", &Date.day_of_week(&1.first) == 1)
~I"2020-07-13"

As I think you know, I have a package that provides calendars other than Calendar.ISO. Would you consider a PR that adds support for non Calendar.ISO calendars to calendar_interval?

I can see if would require a bit of refactoring but I don't think anything especially traumatic.

• Fix bug:

  iex> ~I"2018" |> I.nest(:minute) |> Enum.at(-1) # => ~I"2019-12-31 23:58"

  is wrong
• Decide if we keepnext(~I"2018/2019") #=> ~I"2020" or it should be #=> ~I"2020/2021"
• Decide if we allow to use all precisions in nest/2 and enclosing/2

Today we have:

iex> Enum.to_list(~I"2020-10/11")
[~I"2020-10", ~I"2020-11/12"]

and consequently we have:

iex> CalendarInterval.relation(~I"2020-10/11", ~I"2020-10/12")
:equal

which is wrong, we should have:

iex> Enum.to_list(~I"2020-10/11")
[~I"2020-10", ~I"2020-11"]

Currently the precision is an atom:

iex> ~I[2019-01-01].precision
:day

and so if there's a function that just wants to print, say, day from a given interval it needs to check it like that:

def print_day(%CalendarInterval{precision: precision} = i when precision in [:day, :minute, :second, {:microsecond, 0}, {:microsecond, 1}, ..., {:microsecond, 6}] do
  IO.puts "#{i.day}"
end
def print_day(%CalendarInterval{} =i) do
  raise ArgumentError, "#{inspect(i)} does not have :day precision"
end

An idea is to store which time components we have instead:

iex> ~I[2019-01-01].components
#MapSet<[:year, :month, :day]>

def print_day(%CalendarInterval{} = i) do
  if :day in i.components do
    IO.puts "#{i.day}"
  else
    raise ArgumentError, "#{inspect(i)} does not have :day precision"
  end
end

This is how https://github.com/domainlanguage/time-count handles it.

it simply calls utc_now(:day).

Currently we can only compute the relation of intervals with the same precision:

CalendarInterval.relation(~I"2020", ~I"2020-01/12")
** (FunctionClauseError) no function clause matching in CalendarInterval.relation/2

this restriction seems arbitrary and I think conceptually comparing these makes sense and we should have:

iex> CalendarInterval.relation(~I"2020", ~I"2020-01/12")
:equal

iex> CalendarInterval.relation(~I"2020", ~I"2020-01/11")
:started_by

# etc

wdyt @kipcole9?

Ref #6 (comment)

Ref elixir-lang/elixir#9367