I would prefer the atoms *:before*, and *:after* rather than
:gt/:greater_than/etc. Since we're already solving the problem of
operator/argument ordering, why not remove the final mental barrier of
reasoning about whether a time being "greater than" another time means that
it is before or after? *foo(a, :gt, b)* still requires a second thought
("Is a bigger time earlier or later?"), whereas if I read code that said
*foo(a,
:before, b)* I would feel confident in my understanding after only the
first read.
On Monday, October 31, 2022 at 12:35:05 PM UTC-4 [email protected] wrote:
> I also prefer something like *DateTime.compare(a, operator, b)*.
>
> Operators don't need to be *cryptic* like *:eq*, *:gt*, *:lte*, etc., we
> can use the same comparison operators we already are used to:
>
> *DateTime.compare(a, :<, b)*
> *DateTime.compare(a, :==, b)*
> *DateTime.compare(a, :>=, b)*
>
> It's clear and much less verbose than the Ecto's (which was a great
> suggestion, by the way).
>
> On Monday, October 31, 2022 at 5:23:54 PM UTC+1 [email protected] wrote:
>
>> Hey guys, as an idea why don't we reuse atoms from Ecto:
>>
>> - :less_than
>> - :greater_than
>> - :less_than_or_equal_to
>> - :greater_than_or_equal_to
>> - :equal_to
>> - :not_equal_to
>>
>> I feel like they are fairly common nowadays and even though it's more to
>> type make it easier to understand when you want an inclusive comparison.
>>
>> We can later make it part of all modules that have `compare/2` (Date,
>> DateTime, Time, Version, etc).
>>
>> On Monday, October 31, 2022 at 10:10:09 AM UTC-6 Cliff wrote:
>>
>>> I prefer the form *DateTime.is(a, operator, b)*, but I agree with
>>> others that it would need a more sensible name than "is".
>>>
>>> Regarding the form *DateTime.before?(a, b)*, I could still see myself
>>> getting confused by argument order. *before?(a, b)* might be read as
>>> "before A happened, B happened", rather than the intended "A happened
>>> before B". the *is(a, :before, b)* form, however, is read exactly how
>>> it would be spoken.
>>>
>>> Regarding comparison inclusivity, another possibility is a keyword
>>> option: *DateTime.before?(a, b, inclusive: true)*
>>>
>>> On Monday, October 31, 2022 at 3:45:15 AM UTC-4 [email protected]
>>> wrote:
>>>
>>>> DateTime.before?(a, b) is much nicer than DateTime.compare(a, b) ==
>>>> :lt. It doesn't completely remove the argument order issue but I reckon
>>>> it
>>>> would resolve it for me. I run DateTime.compare(a, b) in iex every time I
>>>> use the function because I'm terribly forgetful and paranoid. I would
>>>> prefer DateTime.eq?/lt?/le?/gt?/ge? instead of
>>>> before?/after?/on_or_before?/on_or_after? which is shorter, matches
>>>> compare/2 and might allow the le/ge equivalents to sneak through. I think
>>>> it would be a shame to leave out le and ge.
>>>>
>>>> DateTime.is?/compare?(a, :lt, b) is a whole lot less ambiguous to me.
>>>> It reads how you would write it in maths or spoken language.
>>>>
>>>> On Monday, 31 October 2022 at 5:08:35 pm UTC+10 [email protected]
>>>> wrote:
>>>>
>>>>> I wonder how much of the issue is the Api and how much of the issue is
>>>>> just the docs? I.e its not a given that all arguments in every position
>>>>> always make sense, but we typically rely on things like elixir_ls to help
>>>>> us when the answer isn't obvious.
>>>>>
>>>>> Could we perhaps just improve the docs in some way? i.e update the
>>>>> specs to say `datetime :: Calendar.datetime(), compares_to ::
>>>>> Calendar.datetime()`, and have the args say `compare(datetime,
>>>>> compares_to)` and have part of the first line of text say something a bit
>>>>> more informative?
>>>>>
>>>>>
>>>>> On Mon, Oct 31, 2022 at 3:02 AM, Jon Rowe <[email protected]> wrote:
>>>>>
>>>>>> I'm not sure the name is right, but I like
>>>>>>
>>>>>> DateTime.is?(a <http://datetime.is/?(a>, operator, b), when operator
>>>>>> :lt | :le | :eq | :ge | :gt, which would capture the :le and :ge options.
>>>>>>
>>>>>>
>>>>>> As a usage api, we could actually have `compare?/3` especially as the
>>>>>> name doesn't overlap with `compare/2` which would hopefully alleviate
>>>>>> anyones concerns about the return type changing
>>>>>>
>>>>>> On Mon, 31 Oct 2022, at 6:23 AM, José Valim wrote:
>>>>>>
>>>>> My thought process is that a simple to use API should be the focus,
>>>>>> because we already have a complete API in Date.compare/2
>>>>>> <http://date.compare/2> and friends.
>>>>>>
>>>>>> On Mon, Oct 31, 2022 at 02:16 Simon McConnell <[email protected]>
>>>>>> wrote:
>>>>>>
>>>>>> would we want on_or_after? and on_or_before? as well then? Or
>>>>>> something like DateTime.is?(a <http://datetime.is/?(a>, operator,
>>>>>> b), when operator :lt | :le | :eq | :ge | :gt, which would capture the
>>>>>> :le
>>>>>> and :ge options.
>>>>>>
>>>>>> On Monday, 31 October 2022 at 7:26:42 am UTC+10 José Valim wrote:
>>>>>>
>>>>>> Thank you!
>>>>>>
>>>>>> A PR that adds before?/after? to Time, Date, NaiveDateTime, and
>>>>>> DateTime is welcome!
>>>>>>
>>>>>>
>>>>>> On Sun, Oct 30, 2022 at 6:46 PM Cliff <[email protected]> wrote:
>>>>>>
>>>>>> I did a bit of research. Many other languages use some form of
>>>>>> operator overloading to do datetime comparison. The ones that do
>>>>>> something
>>>>>> different:
>>>>>>
>>>>>> - Java has LocalDateTime.compareTo(other)
>>>>>>
>>>>>> <https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/LocalDateTime.html#compareTo(java.time.chrono.ChronoLocalDateTime)>,
>>>>>>
>>>>>> returning an integer representing gt/lt/eq. There is also
>>>>>> LocalDateTime.isBefore(other)
>>>>>>
>>>>>> <https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/LocalDateTime.html#isBefore(java.time.chrono.ChronoLocalDateTime)>,
>>>>>>
>>>>>> LocalDateTime.isAfter(other), and LocalDateTime.isEqual(other). The
>>>>>> LocalDateTime.is <http://localdatetime.is/>{Before, After}
>>>>>> methods are non-inclusive (<, >) comparisons. They are instance
>>>>>> methods, so
>>>>>> usage is like `myTime1.isBefore(myTime2)`
>>>>>> - OCaml's "calendar" library provides a Date.compare
>>>>>>
>>>>>> <https://ocaml.org/p/calendar/3.0.0/doc/CalendarLib/Date/index.html#val-compare>
>>>>>>
>>>>>> function that returns an integer representing gt/lt/eq (for use in
>>>>>> OCaml's
>>>>>> List.sort function, which sorts a list according to the provided
>>>>>> comparison
>>>>>> function). It also provides Date.>
>>>>>>
>>>>>> <https://ocaml.org/p/calendar/3.0.0/doc/CalendarLib/Date/index.html#val-(%3E)>,
>>>>>>
>>>>>> and Date.>=
>>>>>>
>>>>>> <https://ocaml.org/p/calendar/3.0.0/doc/CalendarLib/Date/index.html#val-(%3E=)>,
>>>>>>
>>>>>> etc. Worth noting is that OCaml allows you to do expression-level
>>>>>> module
>>>>>> imports, like *Date.(my_t1 > my_t2)* to use Date's *>* function
>>>>>> in the parenthesized expression without needing to *open Date* in
>>>>>> the entire scope ("open" is OCaml's "import") - this could
>>>>>> potentially be
>>>>>> possible in Elixir using a macro?
>>>>>> - Golang: t1.After(t2) <https://pkg.go.dev/time#Time.After>,
>>>>>> t1.Before(t2), t1.Equal(t2). Non-inclusive (> and <).
>>>>>> - Clojure clj-time library: (after? t1 t2)
>>>>>>
>>>>>> <https://clj-time.github.io/clj-time/doc/clj-time.core.html#var-after.3F>,
>>>>>>
>>>>>> (before? t1 t2)
>>>>>>
>>>>>> <https://clj-time.github.io/clj-time/doc/clj-time.core.html#var-before.3F>,
>>>>>>
>>>>>> and (equal? t1 t2)
>>>>>>
>>>>>> <https://clj-time.github.io/clj-time/doc/clj-time.core.html#var-equal.3F>.
>>>>>>
>>>>>> IMO the argument order is still confusing in these.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sunday, October 30, 2022 at 3:15:14 AM UTC-4 José Valim wrote:
>>>>>>
>>>>>> I am definitely in favor of clearer APIs.
>>>>>>
>>>>>> However, it would probably be best to explore how different libraries
>>>>>> in different languages tackle this. Can you please explore this? In
>>>>>> particular, I am curious to know if before/after mean "<" and ">"
>>>>>> respectively or if they mean "<=" and "=>" (I assume the former). And
>>>>>> also
>>>>>> if some libraries feel compelled to expose functions such as
>>>>>> "after_or_equal" or if users would have to write Date.equal?(date1,
>>>>>> date2)
>>>>>> or Date.earlier?(date1, date2), which would end-up doing the double of
>>>>>> conversions.
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
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>>>>>> 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/fcd07389-c6a0-497d-9c09-7f1eacf620c6n%40googlegroups.com
>>>>>>
>>>>>> <https://groups.google.com/d/msgid/elixir-lang-core/fcd07389-c6a0-497d-9c09-7f1eacf620c6n%40googlegroups.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
>>>>>>
>>>>>> --
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>>>>>>
>>>>>> 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/e6c55604-c3ea-464c-908c-5a6092f4d8edn%40googlegroups.com
>>>>>>
>>>>>> <https://groups.google.com/d/msgid/elixir-lang-core/e6c55604-c3ea-464c-908c-5a6092f4d8edn%40googlegroups.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
>>>>>>
>>>>>> --
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>>>>>>
>>>>>> 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/CAGnRm4%2ByT9jA7uqGX0Cyapgfx0AjW%2BU_d4Ai-NQ6vD9UsEb2uQ%40mail.gmail.com
>>>>>>
>>>>>> <https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4%2ByT9jA7uqGX0Cyapgfx0AjW%2BU_d4Ai-NQ6vD9UsEb2uQ%40mail.gmail.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
>>>>>> --
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>>>>>> 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/2e821e87-6ee0-4702-b69f-e2616b61b1dd%40app.fastmail.com
>>>>>>
>>>>>> <https://groups.google.com/d/msgid/elixir-lang-core/2e821e87-6ee0-4702-b69f-e2616b61b1dd%40app.fastmail.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
>>>>>
>>>>>
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