Yes, kind of. But the supposed selling point of compiling into ATS is that one is able to take advantage of the advanced typechecking supported by ATS. Say, you implement a DSL for programming cyptocurrencies; you may want to compile the DSL into ATS so that you can statically verify certain invariants in, say, smart contracts.
On Sat, Mar 10, 2018 at 10:53 AM, Brandon Barker <brandon.bar...@gmail.com> wrote: > 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> >> 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> 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-fun >>>>>> ction-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 :) >>>>>>>>> >>>>>>>>> -- >>>>> You received this message because you are subscribed to a topic in the >>>>> Google Groups "ats-lang-users" group. >>>>> To unsubscribe from this topic, visit https://groups.google.com/d/to >>>>> pic/ats-lang-users/mjS9NtQz6Pg/unsubscribe. >>>>> To unsubscribe from this group and all its topics, send an email to >>>>> ats-lang-user...@googlegroups.com. >>>>> To post to this group, send email to ats-lan...@googlegroups.com. >>>>> Visit this group at https://groups.google.com/group/ats-lang-users. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/ats-lang-users/0609092d-2e >>>>> a6-481b-bf90-7b7bfb1ca52a%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/ats-lang-users/0609092d-2ea6-481b-bf90-7b7bfb1ca52a%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> >>>> >>>> >>>> -- >>>> Brandon Barker >>>> brandon...@gmail.com >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "ats-lang-users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to ats-lang-user...@googlegroups.com. >>> To post to this group, send email to ats-lan...@googlegroups.com. >>> Visit this group at https://groups.google.com/group/ats-lang-users. >>> To view this discussion on the web visit https://groups.google.com/d/ms >>> gid/ats-lang-users/a8e4b46b-41d5-4e19-b7eb-a528e499ea68%40go >>> oglegroups.com >>> <https://groups.google.com/d/msgid/ats-lang-users/a8e4b46b-41d5-4e19-b7eb-a528e499ea68%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> >> -- > You received this message because you are subscribed to the Google Groups > "ats-lang-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to ats-lang-users+unsubscr...@googlegroups.com. > To post to this group, send email to ats-lang-users@googlegroups.com. > Visit this group at https://groups.google.com/group/ats-lang-users. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/ats-lang-users/a0455949-81d5-4743-9646-69fd4fc2642a% > 40googlegroups.com > <https://groups.google.com/d/msgid/ats-lang-users/a0455949-81d5-4743-9646-69fd4fc2642a%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "ats-lang-users" group. 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