I don't know if TASTY <https://github.com/VladimirNik/tasty> might be of
help, either in ideas or actual implementation. Some more indepth
discussion of TAST: https://github.com/twitter/reasonable-scala/issues/21
On Saturday, March 10, 2018 at 10:00:31 AM UTC-5, gmhwxi wrote:
>
> Thanks.
>
> These are all very good points.
>
> I said many times here that I see ATS as both a source language and
> a target language. ATS3 will make it a lot easier for people to use it as a
> target language. I will first use a master design for the syntax of ATS3
> largely based
> on that of ATS2. And an interesting party can design his or her syntax
> that translates
> into this master design. Stay tuned :)
>
>
> On Sat, Mar 10, 2018 at 9:11 AM, Brandon Barker <brandon...@gmail.com
> <javascript:>> wrote:
>
>> While jumping back into ATS, a few other minor things (lots of minor
>> things add up) that might be nicer is string interpolation in the form of
>> python 3.6 or Scala (both are very similar). Here's a copy paste example
>> from python 3.6:
>>
>> 1.
>>
>> name = "Spongebob Squarepants"print(f"Who lives in a Pineapple under the
>> sea? {name}.")
>>
>>
>> Scala would look like:
>>
>> print(s"Who lives in a Pineapple under the sea? $name.")
>>
>>
>> or if 'name' was a general scala expression instead of just an identifier:
>>
>> print(s"Who lives in a Pineapple under the sea? ${name}.")
>>
>>
>> This could also be useful for supporting things like XML interpolation,
>> etc, later on (not that it is a very high priority for most, I imagine ;-)).
>>
>> I don't know how this might work in ATS yet, since scala relies on
>> objects' toString methods, and Python objects have something similar (in
>> both languages, everything is effectively extends object, which I believe
>> has the toString method - by default, this is just the object's address, so
>> not too interesting, but Int of course has a sensible override, as do many
>> objects).
>>
>>
>> 2. OK, maybe this isn't so minor generally. I was using extern in front
>> of a fun in a dats file (I thought this was actually required, but
>> eventually realized that my sleep-deprived brain had read about extern last
>> night and forgot this was only for interfaces, not definitions). This was
>> the error message:
>> 128(line=8, offs=38): error(parsing): [s0tring] is needed
>> Lots of confusion here for a beginner. The user might have to figure out
>> what s0tring is (I think it is either a non-dependent or non-linear string,
>> can't recall and didn't check); also it implies something is needed when it
>> is actually the absence of something that is needed in this particular case
>> (the extern keyword).
>>
>> 3. Simplify ways of defining functions. There seem to be many: fn, fun,
>> fnx. I'd prefer a longer but easier to remember 'tailrec' prefix keyword in
>> some cases to make sure the function is tail recursive and tc-eliminated.
>> Just throwing a quick idea out there, haven't thought about this much, and
>> i'm sure that there are good reasons for why things are the way they are in
>> ATS (I just don't recall all of them).
>>
>>
>> I think if ATS3 is to be done, better error messages should be on about
>> the same priority as improved syntax. On this point, I will say that Scala
>> error messages seem way better generally than Python thanks to typing: you
>> are generally looking at stacktraces in Python, which lack types as well
>> ;-).
>>
>> On Saturday, March 10, 2018 at 7:33:04 AM UTC-5, Brandon Barker wrote:
>>>
>>> Implicit parameters get a bit of a bad reputation, but I don't recall
>>> ever being burned by them in any way even though I use them almost all of
>>> the time; if you have things like implicit strings or even implicit
>>> Map[String, something], that is obviously not good programming style, since
>>> it is relatively easy to add a new implicit in scope (but then you'd get a
>>> compile error anyway as you can't have more than one implicit of the same
>>> type in scope) - they usually need to be rather specific types related to
>>> configuration to make sense. Granted, I have not used them much in the
>>> contradictory fashion that I linked above from Miles Sabin - that is a
>>> rather unusual Scala style, but he hides a lot of that in his Shapeless
>>> library so you can use the features without being directly exposed to (most
>>> of) the unpleasantries.
>>>
>>> I get the sense that dotty isn't adding too many "bells and whistles"
>>> features, and even removing the ones that relate to unsoundness, and making
>>> other features less suprising, like making the extension order no longer
>>> matter: A extends B with C will be the same as A extends C with B now. And
>>> they are adding sensible union types. I believe they are improving
>>> dependent typing in dotty as well. They are removing XML literals, which
>>> I'm actually somewhat sad about, but adding in XML string interpolation.
>>> I've heard there is 0 chance of getting linear types though. Which is why
>>> ATS is really in a good place in terms of features. It has a lot of nice
>>> functional things like Scala (even better: ATS has mutual TCO), has better
>>> linear types than Rust, and has a proof system, neither of which Rust or
>>> Scala has.
>>>
>>> I don't meant to overly sell Scala here; I just think it has some nice
>>> things, and I've been using it a lot, so I wanted to list the things I
>>> thought were nice. Why I use it: as I and some others like to say, it is a
>>> language that gives you types like Java (but better) and concision like
>>> python, while basically giving you the same massive and easy-to-use (once
>>> you are used to it) JVM ecosystem that Java enjoys. So while it may not
>>> have a lot of advanced features compared to some more modern languages, it
>>> already seems to be quite an improvement over the most popular languages
>>> for many applications. Also I had a lot of JVM-related projects lately ;-).
>>>
>>> On Sat, Mar 10, 2018 at 7:09 AM, gmhwxi <gmh...@gmail.com <javascript:>>
>>> wrote:
>>>
>>>>
>>>> The way in which Scala evolves reminds me of C++: Powerful features
>>>> increase productivity but also make it harder and harder to reason about
>>>> code.
>>>>
>>>>
>>>> On Friday, March 9, 2018 at 3:29:18 PM UTC-5, Brandon Barker wrote:
>>>>>
>>>>> Another Scala feature worth looking into: implicit parameters, values,
>>>>> and function types. Dotty has added implicit function types, and I'm not
>>>>> very familiar with all their benefits as yet:
>>>>> https://www.scala-lang.org/blog/2016/12/07/implicit-function-types.html
>>>>>
>>>>> However, implicit parameters alone have been great for me, and could
>>>>> probably go a long way towards reducing some verbosity in ATS. They can
>>>>> also be used in clever ways to create contradictions at compile time, by
>>>>> bringing into scope two implicit values of the same type. I'm not sure if
>>>>> ATS would benefit from that feature, but Scala's type system doesn't
>>>>> allow
>>>>> for things like type b = not a. You can achieve that with implicits:
>>>>> https://gist.github.com/milessabin/c9f8befa932d98dcc7a4
>>>>>
>>>>> On Wednesday, March 7, 2018 at 12:01:03 PM UTC-5, Brandon Barker wrote:
>>>>>>
>>>>>> I forgot to mention, I like the idea of adding a level of indirection
>>>>>> in the syntax for ATS3. Hopefully this could allow something like
>>>>>> scalafix <https://github.com/scalacenter/scalafix> to be developed,
>>>>>> which would not only allow code migration from ATS2 to ATS3, but also
>>>>>> ease
>>>>>> future code migration within ATS3.
>>>>>> to be applied to existing sources
>>>>>>
>>>>>> On Wednesday, March 7, 2018 at 11:52:49 AM UTC-5, Brandon Barker
>>>>>> wrote:
>>>>>>>
>>>>>>> Glad to see this thread is here. I will just share some general
>>>>>>> thoughts for syntax as my ATS is a bit rusty:
>>>>>>>
>>>>>>> 1. I like Scala style syntax - I think it is easy enough to read,
>>>>>>> unless maybe you are doing stuff at the type level, where ATS seems to
>>>>>>> have
>>>>>>> an advantage over Scala. I think Scala is similar to python in a lot of
>>>>>>> ways (especially with Python 3.6 typing styles), aside from making
>>>>>>> indentation part of the syntax. My thought is that Python doing this
>>>>>>> helps
>>>>>>> to force people to write somewhat readable code (think beginner Python
>>>>>>> vs
>>>>>>> beginner Perl), but I think we can assume that if you are coding in
>>>>>>> ATS, or
>>>>>>> at least publishing code in ATS, you will be sensible enough to have
>>>>>>> some
>>>>>>> kind of good programming style. So I would vote for leaving indentation
>>>>>>> to
>>>>>>> a style checker/linter.
>>>>>>> 2. Concision: I sadly don't know Idris or Haskell, and am very
>>>>>>> tempted to learn one of them to get a better appreciation of them, but
>>>>>>> I'd
>>>>>>> rather focus on ATS again. However, I do appreciate that they are
>>>>>>> concise,
>>>>>>> even more so than Scala, which is generally laudable.
>>>>>>> 3. Feature hiding: Facilitate the principle of least powe
>>>>>>> <http://www.lihaoyi.com/post/StrategicScalaStylePrincipleofLeastPower.html>r.
>>>>>>>
>>>>>>> ATS has a lot of advanced features, as does Scala (of course ATS has
>>>>>>> more).
>>>>>>> Scala is pretty good at letting you hide them. I swear, I'd been coding
>>>>>>> in
>>>>>>> Scala for 3 years and was still amazed at how simple you could make the
>>>>>>> code if you try - just take a look at http://www.kogics.net/kojo -
>>>>>>> it is nearly as easy as python I would say, and preferable to me. The
>>>>>>> lack
>>>>>>> of types in the coding examples is almost annoying to me, but I
>>>>>>> understand
>>>>>>> it is beneficial to young readers. Now, I'm not saying we can do all
>>>>>>> this
>>>>>>> in ATS, but Scala is so named because it is a "language that scales
>>>>>>> with
>>>>>>> you", and I believe ATS is this too, but it would be good to make that
>>>>>>> scaling a bit more smooth, like climbing a Olympus Mons
>>>>>>> <https://en.wikipedia.org/wiki/Olympus_Mons#/media/File:Olympus_Mons_Side_View.svg>
>>>>>>>
>>>>>>> rather than K2.
>>>>>>>
>>>>>>>
>>>>>>> Other goals:
>>>>>>> - Build systems: I think cross builds are very important as already
>>>>>>> stated. In scala land, there is Scala (JVM), scala.js, and now
>>>>>>> scala-native. Usually, we can create cross builds by having some source
>>>>>>> that is platform independent (e.g. APIs/interfaces/types) and other
>>>>>>> bits
>>>>>>> that are platform specific and rely on the platform independent bits.
>>>>>>> This
>>>>>>> is great. Related to this, I actually think it may be worthwhile
>>>>>>> looking
>>>>>>> into an existing build tool with a larger community rather than using
>>>>>>> make
>>>>>>> and autotools, which seem to me a bit antiquated and unfriendly to
>>>>>>> other
>>>>>>> platforms. I recall Hongwei and I were both a bit jaded by our
>>>>>>> experience
>>>>>>> with using gradle, so I'm both excited to say Mill
>>>>>>> <https://github.com/lihaoyi/mill> looks like a promising
>>>>>>> alternative, though I'm also hesitant to make a suggestion after the
>>>>>>> last
>>>>>>> failure with Gradle :-) But I believe a lot in Mill's stated goals,
>>>>>>> especially insofar as they overlap with CBT's
>>>>>>> <https://github.com/cvogt/cbt> and the idea of being designed to
>>>>>>> support multiple languages. If we can agree that Scala isn't terrible,
>>>>>>> I
>>>>>>> say let's not reinvent the wheel, and try to comingle a bit with them.
>>>>>>> This
>>>>>>> could be beneficial for both communities. Let's think about using their
>>>>>>> build tools. At the moment, Mill seems to be creating a lot of
>>>>>>> excitement,
>>>>>>> so it might be worth looking into it first.
>>>>>>>
>>>>>>> I'll try to give more concrete feedback in the future.
>>>>>>>
>>>>>>> On Friday, February 9, 2018 at 1:15:22 PM UTC-5, gmhwxi wrote:
>>>>>>>>
>>>>>>>> For the moment, I just want to open a thread for ATS3.
>>>>>>>>
>>>>>>>> I decided to pick ATS/Xanadu for the full project name. I like the
>>>>>>>> name Xanadu
>>>>>>>> because it is poetic and brings a feel of exoticness.
>>>>>>>>
>>>>>>>> ATS3 is supposed to be compiled to ATS2. At least at the beginning.
>>>>>>>> I will try to
>>>>>>>> write more about what I have in mind regarding ATS3.
>>>>>>>>
>>>>>>>> I know that a lot of people have been complaining about the syntax
>>>>>>>> of ATS2. So
>>>>>>>> we can start the effort of designing some "nice" syntax for ATS3.
>>>>>>>> Please feel free
>>>>>>>> to post here if you would like share your opinions and ideas.
>>>>>>>>
>>>>>>>> I will be happy to take the lead but we definitely need to have
>>>>>>>> some form of community
>>>>>>>> effort on this project given its size and scope.
>>>>>>>>
>>>>>>>> Cheers!
>>>>>>>>
>>>>>>>> --Hongwei
>>>>>>>>
>>>>>>>> PS: I felt rushed every time up to now when implementing ATS. This
>>>>>>>> time I am hoping
>>>>>>>> to have the luxury of thinking about implementation a bit before
>>>>>>>> actually doing it :)
>>>>>>>>
>>>>>>>> --
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>>>> .
>>>>
>>>
>>>
>>>
>>> --
>>> Brandon Barker
>>> brandon...@gmail.com <javascript:>
>>>
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