Ah, thanks Kip. Ordinal also has both extended and basic forms too. Here is another question: if we are going to parse ordinals by default, how am I going to format to the ordinal format? Use strftime exclusively?
The other annoyance is while an extended ordinal is distinct enough from a regular extended DateTime, the distinction between basic ordinal and basic DateTime is a single character: “2020012134523”. There will also be ambiguity if we ever decide to support more than four digits on the year. This is enough to say that: * it is not possible to parse all formats within a single function without additional user instructions * if the basic format supports both regular and ordinal, there can be ambiguity if 5 year digits are ever supported in the future This is enough information to me that ordinal should be its own thing, with possibly basic_ordinal and extended_ordinal, but at this point I wonder why add it to the stdlib. On Thu, Feb 4, 2021 at 23:50 Kip Cole <[email protected]> wrote: > From ISO 8601-1:2019(E): > > 5.2.3 Ordinal date > > > 5.2.3.1 Complete representations > > A complete representation of an ordinal date shall be as follows. > > a) Basic format: [year][dayo] EXAMPLE 1 1985102 > > b) Extended format: [year][“-”][dayo] EXAMPLE 2 1985-102 > > If by agreement, expanded representations are used, the formats shall be > as specified below. The interchange parties shall agree on the additional > number of digits in the time scale component year. > > 5.2.3.2 Expanded representations > > In the examples below it has been agreed to expand the time scale > component year with two digits. > > a) Basic format: [±][year(6)][dayo] EXAMPLE 1 +001985102 > > b) Extended format: [±][year(6)][“-”][dayo] EXAMPLE 2 +001985-102 > > On 5 Feb 2021, at 6:45 am, José Valim <[email protected]> wrote: > > > >> I like José's suggesting of supporting a flag, but it gets kind of >> complicated as there are several dimensions here even in our reduced case. >> Dates, times, and datetimes support either basic or extended notations; >> dates and datetimes support calendar dates or ordinal dates; both are >> applicable to any parsing. >> > > Are we 100% sure that ordinal datetimes are part of ISO8601? Kip, can you > please confirm? > > >> If we went with this approach I'd lean towards always accepting either >> form for one of the dimensions, and using flags to the sigil and parsing >> functions to indicate intent for the other. >> > > I am not necessarily worried about sigils because sigils are always > compile-time literals. It is probably fine to enforce a given format there > rather than multiple ones. > > > -- > You received this message because you are subscribed to a topic in the > Google Groups "elixir-lang-core" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/elixir-lang-core/CcXpeMQhsmU/unsubscribe > . > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4JNeGkCNW_6ic2XkxTkFV3uyMT%2B3EZYJuguhzzZfpOnpQ%40mail.gmail.com > <https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4JNeGkCNW_6ic2XkxTkFV3uyMT%2B3EZYJuguhzzZfpOnpQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/15198E56-9D02-4A0E-8E6D-AB905531112A%40gmail.com > <https://groups.google.com/d/msgid/elixir-lang-core/15198E56-9D02-4A0E-8E6D-AB905531112A%40gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4KSXpYWPU-gX53HVGr1efSKbzK-A2bznW7KGG9LmezSGA%40mail.gmail.com.
