10 ms·

Elm 0.14 – Simpler Core, Better Tools

231 points by teamonkey 12y ago

davexunit 12y ago
Awesome. I like the name change from 'lift' to 'map'. Also, the public API diffs that the packaging tool provides looks very neat. Congrats to the Elm team!
bjz_ 12y ago
It's nice to see that they have replaced Either with Result[0]. I wonder if Rust's Result type[1] was the inspiration? (not sure if there is prior art) [0]: http://elm-lang.org/blog/announce/0.14.elm#making-error-handling-easier http://elm-lang.org/blog/announce/0.14.elm#making-error-hand... [1]: http://static.rust-lang.org/doc/master/std/result/index.html http://static.rust-lang.org/doc/master/std/result/index.html
- rjayatilleka 12y ago
  It's possible, but it's really just a name change. And the `Either` monad is used almost entirely for error handling anyway, so Result is a name that many Haskell/Elm users could come up with on their own.
  - kibwen 12y ago
    But the variants being named `Ok` and `Err` match Rust's definition as well, which is why I'd like to second bjz's question as to whether there's some lineage behind this convention.
    - kibwen 12y ago
      I decided to do some archaeology of my own. Here's the first instance of what would become Rust's `Result` type (Oct 28 2011): https://github.com/rust-lang/rust/commit/c1092fb6d88efe51e42df3aae2a321cc669e12a0 https://github.com/rust-lang/rust/commit/c1092fb6d88efe51e42... Note that the type is called `t` since the convention at the time was to name the primary type of a module `t` and then refer to the type as `modulename::t` (shows how far we've come, eh?). At this initial stage the variants are named `ok` and `error`. Also note that at this point in history Rust had had an `either` type for a while (https://github.com/rust-lang/rust/blob/c1092fb6d88efe51e42df3aae2a321cc669e12a0/src/lib/either.rs https://github.com/rust-lang/rust/blob/c1092fb6d88efe51e42df...), which would later be removed as Result gained more traction. Here's the commit where the `error` variant is renamed to `err` (Oct 28 2011, so the same day): https://github.com/rust-lang/rust/commit/2b62a80202e2855d47f20d271842e0e9aec6d8e2 https://github.com/rust-lang/rust/commit/2b62a80202e2855d47f... Here's the first instance of `std::result` being mentioned in the mailing list (Nov 14 2011): http://article.gmane.org/gmane.comp.lang.rust.devel/891 http://article.gmane.org/gmane.comp.lang.rust.devel/891 Where the type itself is renamed to `result` (Mar 13 2012): https://github.com/rust-lang/rust/commit/b968c8e6cd362567bf0047a96d261691dfca43e8 https://github.com/rust-lang/rust/commit/b968c8e6cd362567bf0... Where the type and variant names are capitalized in accordance with the current style guide (Aug 26 2012): https://github.com/rust-lang/rust/commit/0c6e470a257fc546555aa10ededded4a77460a71#diff-3923391a9638ae161ee0e7aaded5ab8a https://github.com/rust-lang/rust/commit/0c6e470a257fc546555... So this convention may very well have originated with Rust.
      - bjz_ 12y ago
        Also interesting to note in the context of the union type discussions below is the use of the `tag` keyword as opposed to the current `enum` for declaring tagged unions.
        kibwen 12y ago
        I always did like `tag`, but I think that's a fight for another year. :)
        wheatBread 12y ago
        At one point we were trying to name every part of a union type in Elm. Calling things "tags" instead of "constructors" seemed quite nice, but ultimately, it seemed like we couldn't get the perfect name.
- wheatBread 12y ago
  I started looking into Rust again while picking the term "union type" because of their choice to use the term "enum". I ran into the Result type in some code I was reading and it just made so much more sense to me as a new person learning the language. Basically, it made it self-evident to me that "a library for error handling should be named with error handling in mind." You will also see a Result type in some Haskell libraries so it's not unprecedented there. I also got tired of explaining "the good result goes in Right, because it's 'Right'" like I'm endlessly telling a bad dad-joke.
  - bjz_ 12y ago
    Yeah, we used to have an Either type in the Rust std, but it was pretty much never used because we had Result.
- Dewie 12y ago
  "Result" is a pretty opaque name: any value or type can be called a "Result", really. "Either" at least hints to the fact that it is either-this-or-that. "Either" is IMO a nice counterpart to tuple types: one is a generic sum, the other is a generic product. People could complain that a tuple of ints are less descriptive than just using a constructor with a more descriptive name - like "Pair" or "Coordinate", depending on its intended application. Having a specialized type for error handling makes sense, though.
  - bjz_ 12y ago
    It doesn't seem scalable though, because it only works for two types. It would be better to have some sort of structural union type (like Ceyleon).
    - jmite 12y ago
      But it's defined as 'Result error value', which means you can just make 'error' a union type, and now you have multiple kinds of exceptions. When you specify an error type, you're basically specifying all the types of exceptions that the evaluation can raise.
      - bjz_ 12y ago
        But it would be less descriptive from an API point of view. Which type is the return value? Of course we are now in the land of hypotheticals.
lucian1900 12y ago
Very cool. Interestingly enough, the dice is loaded. If you click long enough, you'll get an upside down V shape.
- davidrusu 12y ago
  There's actually 2 dices, so there are quite a few more ways to get a 7 than to get a 2 7 = 1+6, 2+5, 3+4, 4+3, 5+2, 6+1 2 = 1+1, 1+1
  - e12e 12y ago
    Or, the difference between 1d12 and 2d6 (roll of one 12 sided die, vs summing the roll of two six sided dice).
- flebron 12y ago
  The dice aren't loaded, you're just seeing a binomial distribution[1][2] :) [1] http://en.wikipedia.org/wiki/Binomial_distribution http://en.wikipedia.org/wiki/Binomial_distribution [2] http://hyperphysics.phy-astr.gsu.edu/hbase/math/dice.html#c2 http://hyperphysics.phy-astr.gsu.edu/hbase/math/dice.html#c2
thewarrior 12y ago
Is anyone here using Elm in production ?
- rtfeldman 12y ago
  Dreamwriter uses it, although Dreamwriter is still pre-1.0. https://github.com/rtfeldman/dreamwriter https://github.com/rtfeldman/dreamwriter
- RehnoLindeque 12y ago
  We've been using it to render schematic symbols and PCB footprints at CircuitHub.com (this has been going on for a couple of months). I'm testing it out in other areas of the product at the moment, so if all goes well additional Elm widgets might land on our site very soon.
- etaque 12y ago
  Here on PlayTacks, a sailing simulation: http://www.playtacks.com/ http://www.playtacks.com/ Nothing serious though...
tree_of_item 12y ago
Eh, that's a tagged union, but I think "union type" usually refers to untagged unions like you see in more dynamic languages such as TypeScript and Facebook's Flow. Tagged unions are typically called sum types. That is, searching for "union type" is gonna give you results about untagged unions or C style unions. I'm not sure this new terminology helps.
- johnpmayer 12y ago
  For the record, I voted for enum, like in rust-lang ;-) This was going to be contentious no matter what. For what it's worth, Wikipedia (top Google result) seems to have a compatible story. Luckily, it's just a conversation change. I think it will be fine, and net more helpful than damaging. The overall goals are intuition and accessibility.
  - kibwen 12y ago
    > For the record, I voted for enum, like in rust-lang ;-) Funny, because there's actually a long, long history of debate around whether Rust should refer to them as unions rather than enums (and change the keyword correspondingly). :) Here's the most recent one that I know of: https://github.com/rust-lang/rfcs/pull/27 https://github.com/rust-lang/rfcs/pull/27 Swift seems to have followed Rust's example with its terminology here, so this issue is hardly settled. It may shake out such that `enum` is used for tagged unions where the variants are declared as part of the type (`enum Foo { Bar, Baz}`) (and hence the variants can't be shared between types, at least not without wrapping in a newly-defined variant), whereas `union` is used for tagged unions where the type is composed from multiple existing types (`type Bar; type Baz; union Foo { Bar | Baz }`).
- brandonbloom 12y ago
  Depending on who you ask, there's another established meaning of "union type" when contrasting it against "sum type" in a safe context. Sum types are discriminated unions in which each constructor tag in the union is disjoint from each other member and all other types. In contrast, "union type" tends to imply that you can share constructors/tags between types. For example Julia: http://docs.julialang.org/en/release-0.3/manual/types/#type-unions http://docs.julialang.org/en/release-0.3/manual/types/#type-... Typed Racket: http://docs.racket-lang.org/ts-guide/beginning.html#%28part._.Datatypes_and_.Unions%29 http://docs.racket-lang.org/ts-guide/beginning.html#%28part.... Haskell: http://okmij.org/ftp/Haskell/extensible/#open-union http://okmij.org/ftp/Haskell/extensible/#open-union And many more.
jmgrosen 12y ago
That's pretty ridiculous. Literally the day after I start working on my Elm project in a couple months... Anyway, the changes here do look pretty nice. Looking at the docs, it seems that they've added more examples, which is always appreciated! I still don't like the impurity that comes with the Signal.Channel, though... not that I have a better idea.
StevePerkins 12y ago
Have there been any performance improvements under Firefox? Almost every Elm demo that I've seen so far has been basically unusable under that browser. I've been told that the issue is some difference between Chrome and FF with canvas drawing... but regardless of where the fault lies, Elm is pretty much a Chrome-only technology until that gets worked out.
- jcollard 12y ago
  Someone please correct me if I am wrong but I believe the answer is yes. I believe this is the relevant PR: https://github.com/elm-lang/core/pull/25 https://github.com/elm-lang/core/pull/25 I believe the original improvements were done here: https://github.com/jwmerrill/elm-animation-frame https://github.com/jwmerrill/elm-animation-frame I modified a game I wrote to use the modified run time. I can see a huge difference between the two in Firefox. Unmodified: http://jcollard.github.io/elm-flyer-old/ http://jcollard.github.io/elm-flyer-old/ Modified: http://jcollard.github.io/elm-flyer/ http://jcollard.github.io/elm-flyer/
  - wheatBread 12y ago
    Yeah, this is in for 0.14. I forgot to mention it in the announcement, but Jason deserves a huge thank you for this improvement!
  - jwmerrill 12y ago
    Author of that PR here. It may help Firefox some, but in my experiments I'm still seeing that driving canvas animations with Elm performs much better in Chrome than in Firefox. If there are any Firefox engineers reading this, maybe there is a good benchmark to be extracted out of this observation? I'd be interested in discussing this with someone. Feel free to reach out at the e-mail address in my profile.
dcre 12y ago
If you're interested in Elm but don't really know what it's about, I highly recommend Evan's Strange Loop talk, "Controlling Time and Space: understanding the many formulations of FRP." It will help to already have a bit of background in functional programming. https://www.youtube.com/watch?v=Agu6jipKfYw https://www.youtube.com/watch?v=Agu6jipKfYw
- musername 12y ago
  Started watching, the slides animations are a nice enhancement. Are they perhaps written in elm?
  - dcre 12y ago
    He works for a company called Prezi whose product is the slideshow software he's using. God, I sound like a stalker, don't I.
lsjroberts 12y ago
I used Elm for my Ludum Dare entry. As a first attempt using a functional language I definitely did many things wrong, but I found it very easy to iterate. Great language and I'm going to look into going further with it for game development.
rnhmjoj 12y ago
What is the point of changes like [] to List, mod to %, . to << and >>? Is it just aesthetics? When I looked at Elm it was really similar to Haskell. After I learned a bit of Elm I dove into Haskell. Now that I'm coming back to Elm I'm having problems because I confuse this different syntaxes many times. I hoped they could maintain the language more similar to it to make the switch between them easier.
- fallat 12y ago
  Yes, aesthetics. Here is another one: : and :: are reversed. They have no intention of making them more similar- in fact I was told there is going to be more subtle diverging happening. Elm was really cool for me too at first, but these subtleties are just a pain. I am now using haste (haste-lang.org), which seems to have really come a long way over the course of its 3 year life span. I highly recommend it to those wanting to use Haskell as a front-end web development language.
  - rnhmjoj 12y ago
    Wow, haste is great. Thank you for sharing.
  - throwaway77221 12y ago
    Completely agree. Not only these subtle changes but also the Evan's resistance to include common typeclasses and generally anti-intellectual attitude and rudeness have turned me off completely. Evan also plays favorites a lot and has a rather naive view of social justice (which he views himself as some kind of champion for). Purescript has now become my alternative but I will take a look at Haste (ghcjs may be another possibility to look into).
  - throwaway19283 12y ago
    Oh, yes, reversing : and :: makes it soooooo much easier for beginners to approach. The elm community is full of inane bikeshedding like this. I bet they spent days and even weeks arguing the merits of reversing these vs not reversing them.
- 12y ago
AlexanderDhoore 12y ago
Elm really is fascinating... Am I the only one who thinks FRP is just a reincarnation of dataflow programming? I'm learning Verilog in my spare time, because I want to implement a dataflow/FRP language in hardware. (People tried to build massively parallel hardware in the past to run dataflow languages... I'm pretty sure it's a good idea.) Should be interesting!
- tree_of_item 12y ago
  That's like saying Rust is "just a reincarnation of imperative programming". Dataflow is an extremely general category, there's a lot of room for important differences; describing something as "dataflow" doesn't really tell you much about it.
  - AlexanderDhoore 12y ago
    Well, of course I'm generalising here. It's just that, to me, dataflow and FRP look very similar. At least once you go past syntax and superficial things. (I just realised you meant to say that FRP is a subset of dataflow. I agree!)
couchand 12y ago
The benefits are actually much deeper though. Now that we know exactly how the API has changed, it is possible to automatically enforce strict versioning rules. If there are breaking changes, the new release must be a major version bump. This is very interesting to me. It demands consideration: do we need a person to manually bump the version anymore at all? If you can statically verify that a change meets the criteria, couldn't the package publishing process autoincrement the appropriate version segment and be done with it?
- riffraff 12y ago
  there are probably cases in which you want to change the version independently of API changes, i.e. "going stable" (0.x to 1.0), major internal changes, new interfaces with deprecations of the old ones etc.
  - couchand 12y ago
    Good point, you still need an escape hatch to bump a version segment higher than the minimum necessary one, for many reasons. I'm not sure I agree that the phrase "going stable" really applies to a semver project. The most stable release would just be the highest number in each segment. Version 1.0.1 is almost by definition going to be more stable than 1.0.0, since the changes are only backwards-compatible bug fixes. At least that's my understanding of semver.
    - riffraff 12y ago
      semver has a special case for 0.x, which is basically "before 1.0 there are no guarantees". In their words: > Major version zero (0.y.z) is for initial development. Anything may change at any time. The public API should not be considered stable. (Yes, this means that you can use 0.x and declare yourself "semver compatible" and break on any patch release)
- zimbatm 12y ago
  It seems doable to differentiate additions from (breaking) changes if all the API is statically defined. It would be nice to even have the feedback on larger changes. That being said it's possible to change a library's behaviour without touching the API. Consider the following diff: -add a b = a + b +add a b = a - b Granted the example is simplistic. With the API versioning system in place the author should have renamed the method and would have gotten the right result. It's just to show that it wouldn't be a silver bullet.
pflanze 12y ago
The Elm website is blank without JavaScript enabled. Here's a script to extract the Markdown in the given page and optionally format it without having to enable JavaScript in the browser: https://github.com/pflanze/de-elm https://github.com/pflanze/de-elm (Edit: here's a copy of the content of the linked page: https://github.com/pflanze/de-elm/blob/master/examples/announce-0.14.elm.md https://github.com/pflanze/de-elm/blob/master/examples/annou... . Tell me if you don't like this and I'll remove it again.)
- jmite 12y ago
  I don't know why people always bring this up. Elm is a compile-to-JS language. The website is implemented in Elm.
  - pflanze 12y ago
    I understand both points. Or more precisely, after viewing the source of the page, I made a good guess that the reason this is js only is that Elm, if I remember correctly, is the language that formats pages without (just) relying on CSS, by using JavaScript, thus I'm totally understanding; although I'd like to make the point that I only got there since I had seen Elm discussed previously, and looking at the regular code in the source and hence guessing that it's compiler output. Perhaps it's not wise for the creators of the language to presume as much. So, there's a practical point to this, which is that I wanted to read the page, and a mixed practical/political point which is that I don't want to enable JavaScript if I don't absolutely have to. So I sat down and figured out what can be done...
    - pasbesoin 12y ago
      Basically, I agree with the dissatisfaction with JS-mandatory basic, informative pages. I'm sure this will cease to be useful at some point, but for the moment, I find that some of the time, running the URL in question through Google Cache produces a useful view. Of course, Google properties themselves increasingly insist upon JS, even for basic "read-only" views. At least I have some confidence that Google is performing some measure of vetting their own JS against particularly the security problems that most concern me. Here's the OP URL, via Google Cache: http://webcache.googleusercontent.com/search?q=cache:http%3A%2F%2Felm-lang.org%2Fblog%2Fannounce%2F0.14.elm http://webcache.googleusercontent.com/search?q=cache:http%3A...
shard 12y ago
For a second I had thought that someone had released an update for the Elm mail client. Color me disappointed (although I am more of a Pine guy myself, up to ~2006 at least).
peapicker 12y ago
I must be getting old... I saw the headline and thought "Isn't the elm mail client at a higher version than that?"

231 points by teamonkey 12y ago

Awesome. I like the name change from 'lift' to 'map'. Also, the public API diffs that the packaging tool provides looks very neat. Congrats to the Elm team!

bjz_ 12y ago

It's nice to see that they have replaced Either with Result[0]. I wonder if Rust's Result type[1] was the inspiration? (not sure if there is prior art) [0]: http://elm-lang.org/blog/announce/0.14.elm#making-error-handling-easier http://elm-lang.org/blog/announce/0.14.elm#making-error-hand... [1]: http://static.rust-lang.org/doc/master/std/result/index.html http://static.rust-lang.org/doc/master/std/result/index.html

rjayatilleka 12y ago
It's possible, but it's really just a name change. And the `Either` monad is used almost entirely for error handling anyway, so Result is a name that many Haskell/Elm users could come up with on their own.
- kibwen 12y ago
  But the variants being named `Ok` and `Err` match Rust's definition as well, which is why I'd like to second bjz's question as to whether there's some lineage behind this convention.
  - kibwen 12y ago
    I decided to do some archaeology of my own. Here's the first instance of what would become Rust's `Result` type (Oct 28 2011): https://github.com/rust-lang/rust/commit/c1092fb6d88efe51e42df3aae2a321cc669e12a0 https://github.com/rust-lang/rust/commit/c1092fb6d88efe51e42... Note that the type is called `t` since the convention at the time was to name the primary type of a module `t` and then refer to the type as `modulename::t` (shows how far we've come, eh?). At this initial stage the variants are named `ok` and `error`. Also note that at this point in history Rust had had an `either` type for a while (https://github.com/rust-lang/rust/blob/c1092fb6d88efe51e42df3aae2a321cc669e12a0/src/lib/either.rs https://github.com/rust-lang/rust/blob/c1092fb6d88efe51e42df...), which would later be removed as Result gained more traction. Here's the commit where the `error` variant is renamed to `err` (Oct 28 2011, so the same day): https://github.com/rust-lang/rust/commit/2b62a80202e2855d47f20d271842e0e9aec6d8e2 https://github.com/rust-lang/rust/commit/2b62a80202e2855d47f... Here's the first instance of `std::result` being mentioned in the mailing list (Nov 14 2011): http://article.gmane.org/gmane.comp.lang.rust.devel/891 http://article.gmane.org/gmane.comp.lang.rust.devel/891 Where the type itself is renamed to `result` (Mar 13 2012): https://github.com/rust-lang/rust/commit/b968c8e6cd362567bf0047a96d261691dfca43e8 https://github.com/rust-lang/rust/commit/b968c8e6cd362567bf0... Where the type and variant names are capitalized in accordance with the current style guide (Aug 26 2012): https://github.com/rust-lang/rust/commit/0c6e470a257fc546555aa10ededded4a77460a71#diff-3923391a9638ae161ee0e7aaded5ab8a https://github.com/rust-lang/rust/commit/0c6e470a257fc546555... So this convention may very well have originated with Rust.
    - bjz_ 12y ago
      Also interesting to note in the context of the union type discussions below is the use of the `tag` keyword as opposed to the current `enum` for declaring tagged unions.
      - kibwen 12y ago
        I always did like `tag`, but I think that's a fight for another year. :)
      - wheatBread 12y ago
        At one point we were trying to name every part of a union type in Elm. Calling things "tags" instead of "constructors" seemed quite nice, but ultimately, it seemed like we couldn't get the perfect name.
wheatBread 12y ago
I started looking into Rust again while picking the term "union type" because of their choice to use the term "enum". I ran into the Result type in some code I was reading and it just made so much more sense to me as a new person learning the language. Basically, it made it self-evident to me that "a library for error handling should be named with error handling in mind." You will also see a Result type in some Haskell libraries so it's not unprecedented there. I also got tired of explaining "the good result goes in Right, because it's 'Right'" like I'm endlessly telling a bad dad-joke.
- bjz_ 12y ago
  Yeah, we used to have an Either type in the Rust std, but it was pretty much never used because we had Result.
Dewie 12y ago
"Result" is a pretty opaque name: any value or type can be called a "Result", really. "Either" at least hints to the fact that it is either-this-or-that. "Either" is IMO a nice counterpart to tuple types: one is a generic sum, the other is a generic product. People could complain that a tuple of ints are less descriptive than just using a constructor with a more descriptive name - like "Pair" or "Coordinate", depending on its intended application. Having a specialized type for error handling makes sense, though.
- bjz_ 12y ago
  It doesn't seem scalable though, because it only works for two types. It would be better to have some sort of structural union type (like Ceyleon).
  - jmite 12y ago
    But it's defined as 'Result error value', which means you can just make 'error' a union type, and now you have multiple kinds of exceptions. When you specify an error type, you're basically specifying all the types of exceptions that the evaluation can raise.
    - bjz_ 12y ago
      But it would be less descriptive from an API point of view. Which type is the return value? Of course we are now in the land of hypotheticals.

lucian1900 12y ago

Very cool. Interestingly enough, the dice is loaded. If you click long enough, you'll get an upside down V shape.

davidrusu 12y ago
There's actually 2 dices, so there are quite a few more ways to get a 7 than to get a 2 7 = 1+6, 2+5, 3+4, 4+3, 5+2, 6+1 2 = 1+1, 1+1
- e12e 12y ago
  Or, the difference between 1d12 and 2d6 (roll of one 12 sided die, vs summing the roll of two six sided dice).
flebron 12y ago
The dice aren't loaded, you're just seeing a binomial distribution[1][2] :) [1] http://en.wikipedia.org/wiki/Binomial_distribution http://en.wikipedia.org/wiki/Binomial_distribution [2] http://hyperphysics.phy-astr.gsu.edu/hbase/math/dice.html#c2 http://hyperphysics.phy-astr.gsu.edu/hbase/math/dice.html#c2

thewarrior 12y ago

Is anyone here using Elm in production ?

rtfeldman 12y ago
Dreamwriter uses it, although Dreamwriter is still pre-1.0. https://github.com/rtfeldman/dreamwriter https://github.com/rtfeldman/dreamwriter
RehnoLindeque 12y ago
We've been using it to render schematic symbols and PCB footprints at CircuitHub.com (this has been going on for a couple of months). I'm testing it out in other areas of the product at the moment, so if all goes well additional Elm widgets might land on our site very soon.
etaque 12y ago
Here on PlayTacks, a sailing simulation: http://www.playtacks.com/ http://www.playtacks.com/ Nothing serious though...

tree_of_item 12y ago

Eh, that's a tagged union, but I think "union type" usually refers to untagged unions like you see in more dynamic languages such as TypeScript and Facebook's Flow. Tagged unions are typically called sum types. That is, searching for "union type" is gonna give you results about untagged unions or C style unions. I'm not sure this new terminology helps.

johnpmayer 12y ago
For the record, I voted for enum, like in rust-lang ;-) This was going to be contentious no matter what. For what it's worth, Wikipedia (top Google result) seems to have a compatible story. Luckily, it's just a conversation change. I think it will be fine, and net more helpful than damaging. The overall goals are intuition and accessibility.
- kibwen 12y ago
  > For the record, I voted for enum, like in rust-lang ;-) Funny, because there's actually a long, long history of debate around whether Rust should refer to them as unions rather than enums (and change the keyword correspondingly). :) Here's the most recent one that I know of: https://github.com/rust-lang/rfcs/pull/27 https://github.com/rust-lang/rfcs/pull/27 Swift seems to have followed Rust's example with its terminology here, so this issue is hardly settled. It may shake out such that `enum` is used for tagged unions where the variants are declared as part of the type (`enum Foo { Bar, Baz}`) (and hence the variants can't be shared between types, at least not without wrapping in a newly-defined variant), whereas `union` is used for tagged unions where the type is composed from multiple existing types (`type Bar; type Baz; union Foo { Bar | Baz }`).
brandonbloom 12y ago
Depending on who you ask, there's another established meaning of "union type" when contrasting it against "sum type" in a safe context. Sum types are discriminated unions in which each constructor tag in the union is disjoint from each other member and all other types. In contrast, "union type" tends to imply that you can share constructors/tags between types. For example Julia: http://docs.julialang.org/en/release-0.3/manual/types/#type-unions http://docs.julialang.org/en/release-0.3/manual/types/#type-... Typed Racket: http://docs.racket-lang.org/ts-guide/beginning.html#%28part._.Datatypes_and_.Unions%29 http://docs.racket-lang.org/ts-guide/beginning.html#%28part.... Haskell: http://okmij.org/ftp/Haskell/extensible/#open-union http://okmij.org/ftp/Haskell/extensible/#open-union And many more.

jmgrosen 12y ago

That's pretty ridiculous. Literally the day after I start working on my Elm project in a couple months... Anyway, the changes here do look pretty nice. Looking at the docs, it seems that they've added more examples, which is always appreciated! I still don't like the impurity that comes with the Signal.Channel, though... not that I have a better idea.

StevePerkins 12y ago

Have there been any performance improvements under Firefox? Almost every Elm demo that I've seen so far has been basically unusable under that browser. I've been told that the issue is some difference between Chrome and FF with canvas drawing... but regardless of where the fault lies, Elm is pretty much a Chrome-only technology until that gets worked out.

jcollard 12y ago
Someone please correct me if I am wrong but I believe the answer is yes. I believe this is the relevant PR: https://github.com/elm-lang/core/pull/25 https://github.com/elm-lang/core/pull/25 I believe the original improvements were done here: https://github.com/jwmerrill/elm-animation-frame https://github.com/jwmerrill/elm-animation-frame I modified a game I wrote to use the modified run time. I can see a huge difference between the two in Firefox. Unmodified: http://jcollard.github.io/elm-flyer-old/ http://jcollard.github.io/elm-flyer-old/ Modified: http://jcollard.github.io/elm-flyer/ http://jcollard.github.io/elm-flyer/
- wheatBread 12y ago
  Yeah, this is in for 0.14. I forgot to mention it in the announcement, but Jason deserves a huge thank you for this improvement!
- jwmerrill 12y ago
  Author of that PR here. It may help Firefox some, but in my experiments I'm still seeing that driving canvas animations with Elm performs much better in Chrome than in Firefox. If there are any Firefox engineers reading this, maybe there is a good benchmark to be extracted out of this observation? I'd be interested in discussing this with someone. Feel free to reach out at the e-mail address in my profile.

dcre 12y ago

If you're interested in Elm but don't really know what it's about, I highly recommend Evan's Strange Loop talk, "Controlling Time and Space: understanding the many formulations of FRP." It will help to already have a bit of background in functional programming. https://www.youtube.com/watch?v=Agu6jipKfYw https://www.youtube.com/watch?v=Agu6jipKfYw

musername 12y ago
Started watching, the slides animations are a nice enhancement. Are they perhaps written in elm?
- dcre 12y ago
  He works for a company called Prezi whose product is the slideshow software he's using. God, I sound like a stalker, don't I.

lsjroberts 12y ago

I used Elm for my Ludum Dare entry. As a first attempt using a functional language I definitely did many things wrong, but I found it very easy to iterate. Great language and I'm going to look into going further with it for game development.

rnhmjoj 12y ago

What is the point of changes like [] to List, mod to %, . to << and >>? Is it just aesthetics? When I looked at Elm it was really similar to Haskell. After I learned a bit of Elm I dove into Haskell. Now that I'm coming back to Elm I'm having problems because I confuse this different syntaxes many times. I hoped they could maintain the language more similar to it to make the switch between them easier.

fallat 12y ago
Yes, aesthetics. Here is another one: : and :: are reversed. They have no intention of making them more similar- in fact I was told there is going to be more subtle diverging happening. Elm was really cool for me too at first, but these subtleties are just a pain. I am now using haste (haste-lang.org), which seems to have really come a long way over the course of its 3 year life span. I highly recommend it to those wanting to use Haskell as a front-end web development language.
- rnhmjoj 12y ago
  Wow, haste is great. Thank you for sharing.
- throwaway77221 12y ago
  Completely agree. Not only these subtle changes but also the Evan's resistance to include common typeclasses and generally anti-intellectual attitude and rudeness have turned me off completely. Evan also plays favorites a lot and has a rather naive view of social justice (which he views himself as some kind of champion for). Purescript has now become my alternative but I will take a look at Haste (ghcjs may be another possibility to look into).
- throwaway19283 12y ago
  Oh, yes, reversing : and :: makes it soooooo much easier for beginners to approach. The elm community is full of inane bikeshedding like this. I bet they spent days and even weeks arguing the merits of reversing these vs not reversing them.
12y ago

AlexanderDhoore 12y ago

Elm really is fascinating... Am I the only one who thinks FRP is just a reincarnation of dataflow programming? I'm learning Verilog in my spare time, because I want to implement a dataflow/FRP language in hardware. (People tried to build massively parallel hardware in the past to run dataflow languages... I'm pretty sure it's a good idea.) Should be interesting!

tree_of_item 12y ago
That's like saying Rust is "just a reincarnation of imperative programming". Dataflow is an extremely general category, there's a lot of room for important differences; describing something as "dataflow" doesn't really tell you much about it.
- AlexanderDhoore 12y ago
  Well, of course I'm generalising here. It's just that, to me, dataflow and FRP look very similar. At least once you go past syntax and superficial things. (I just realised you meant to say that FRP is a subset of dataflow. I agree!)

couchand 12y ago

The benefits are actually much deeper though. Now that we know exactly how the API has changed, it is possible to automatically enforce strict versioning rules. If there are breaking changes, the new release must be a major version bump. This is very interesting to me. It demands consideration: do we need a person to manually bump the version anymore at all? If you can statically verify that a change meets the criteria, couldn't the package publishing process autoincrement the appropriate version segment and be done with it?

riffraff 12y ago
there are probably cases in which you want to change the version independently of API changes, i.e. "going stable" (0.x to 1.0), major internal changes, new interfaces with deprecations of the old ones etc.
- couchand 12y ago
  Good point, you still need an escape hatch to bump a version segment higher than the minimum necessary one, for many reasons. I'm not sure I agree that the phrase "going stable" really applies to a semver project. The most stable release would just be the highest number in each segment. Version 1.0.1 is almost by definition going to be more stable than 1.0.0, since the changes are only backwards-compatible bug fixes. At least that's my understanding of semver.
  - riffraff 12y ago
    semver has a special case for 0.x, which is basically "before 1.0 there are no guarantees". In their words: > Major version zero (0.y.z) is for initial development. Anything may change at any time. The public API should not be considered stable. (Yes, this means that you can use 0.x and declare yourself "semver compatible" and break on any patch release)
zimbatm 12y ago
It seems doable to differentiate additions from (breaking) changes if all the API is statically defined. It would be nice to even have the feedback on larger changes. That being said it's possible to change a library's behaviour without touching the API. Consider the following diff: -add a b = a + b +add a b = a - b Granted the example is simplistic. With the API versioning system in place the author should have renamed the method and would have gotten the right result. It's just to show that it wouldn't be a silver bullet.

pflanze 12y ago

The Elm website is blank without JavaScript enabled. Here's a script to extract the Markdown in the given page and optionally format it without having to enable JavaScript in the browser: https://github.com/pflanze/de-elm https://github.com/pflanze/de-elm (Edit: here's a copy of the content of the linked page: https://github.com/pflanze/de-elm/blob/master/examples/announce-0.14.elm.md https://github.com/pflanze/de-elm/blob/master/examples/annou... . Tell me if you don't like this and I'll remove it again.)

jmite 12y ago
I don't know why people always bring this up. Elm is a compile-to-JS language. The website is implemented in Elm.
- pflanze 12y ago
  I understand both points. Or more precisely, after viewing the source of the page, I made a good guess that the reason this is js only is that Elm, if I remember correctly, is the language that formats pages without (just) relying on CSS, by using JavaScript, thus I'm totally understanding; although I'd like to make the point that I only got there since I had seen Elm discussed previously, and looking at the regular code in the source and hence guessing that it's compiler output. Perhaps it's not wise for the creators of the language to presume as much. So, there's a practical point to this, which is that I wanted to read the page, and a mixed practical/political point which is that I don't want to enable JavaScript if I don't absolutely have to. So I sat down and figured out what can be done...
  - pasbesoin 12y ago
    Basically, I agree with the dissatisfaction with JS-mandatory basic, informative pages. I'm sure this will cease to be useful at some point, but for the moment, I find that some of the time, running the URL in question through Google Cache produces a useful view. Of course, Google properties themselves increasingly insist upon JS, even for basic "read-only" views. At least I have some confidence that Google is performing some measure of vetting their own JS against particularly the security problems that most concern me. Here's the OP URL, via Google Cache: http://webcache.googleusercontent.com/search?q=cache:http%3A%2F%2Felm-lang.org%2Fblog%2Fannounce%2F0.14.elm http://webcache.googleusercontent.com/search?q=cache:http%3A...

shard 12y ago

For a second I had thought that someone had released an update for the Elm mail client. Color me disappointed (although I am more of a Pine guy myself, up to ~2006 at least).

peapicker 12y ago

I must be getting old... I saw the headline and thought "Isn't the elm mail client at a higher version than that?"