Add some Time functions

[MaisaMilena]

Inspired in pretty-ms and parse-ms. Converts and show time from milliseconds to days, hours, minutes, etc.

Also, add some numbers.max as an example of how to write the numbers

need help:

I have to improve Time.ex but:

• Following Buck example using The doesn't work because String.eql doesn't evaluate to a Bool

Time.ex.show_secs: The(_, Bool.true)
   let time = Time.show(Time.ex.parse, Bool.false)
   case time: 
   | The.value<>(String.eql(time.seconds, "20s"));

• Using Victor's suggestion doesn't type check

Time.ex: Bool
   Bool.and(Time.ex.test_days, Bool.false)

Time.ex.test: Time.ex.test_days == Bool.true
  _

[VictorTaelin]

@johnchandlerburnham I don't think the licenses belong here. What is your take on the matter?

[MaisaMilena]

Despite I changed a lot of things in the parse-ms, the essence of the code is the same. For pretty-ms I just saw some examples on how it would output but it's my code.

I think that a lot of cases of copying libs to use in Formality will happen. In the MIT License, this is what made me copy the license as a code: "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software."

[johnchandlerburnham]

Copyright doesn't cover the essence of the idea expressed in code, only the concrete implementation. If you directly copy files, functions or text, then it needs to preserve the license, but you haven't done that here. A port is generally a derivative work which generates a fresh copyright (covered here by the root LICENSE file). I would remove the license text and just include a comment that links to the repo you were inspired by and gives credit to its author as a matter of good open source friendliness.

[VictorTaelin]

The reason Text.ex.show_secs doesn't work is that, inside the case, time.seconds is a variable which isn't true yet, so you'd need a dependent motive. An alternative is to extract the seconds from time and use def:

Time.ex.show_secs: The(_, Bool.true)
  let time = Time.show(Time.ex.parse, Bool.false)
  def secs = case time: | time.seconds;
  The.value<>(String.eql(secs, "20s"))

But this also doesn't type-check because it depends on U64 functions that aren't implemented on lib yet, so they can't be normalized on the type level (even though they work in JS). We need those for the type-checker to get unstuck.