I use constructors with multiple values a lot, so please don’t take them away.
> On Jan 15, 2017, at 11:15 AM, Maxime Dantec <[email protected]> wrote: > > Not really, take this example : > > type Foo = Bar ( Int, Bool, (String, Foo) ) > > foo : Int -> Bool -> (String, Foo) -> Foo > foo = Foo << (,,) How is << (,,) easier to explain than ADTs? ADTs are not just some syntax to be leaned, they are a powerful way to model data. The particular syntax is sparse, and you could argue the addition of labels would be an improvement, but I know many people who use elm or Haskell data types to document models before implementing them in other languages. It is so quick, it is like type-checked pseudo-code. > > And again, it seems to be the exception to have multiple values. > > On Sunday, January 15, 2017 at 5:09:46 PM UTC+1, Janis Voigtländer wrote: > This would take away the possibility of partially applying the constructors > like Bar. Not a good idea. There's a reason these have curried types. > > > Am 15.01.2017 um 17:03 schrieb Maxime Dantec <[email protected] <javascript:>>: > >> Not really, sorry I assumed that everybody knew how elm compile values but >> it was very presumptuous. Currently, all type values in Elm are converted in >> Javascript values in the { ctor, _0, _1... _n } shape. For example, Nothing >> becomes { ctor: "Nothing" } and (Just 10) becomes { ctor : "Just", _0: 10 }. >> The {type, value} part, would change that to : Nothing becomes { type: >> "Nothing" } and (Just 10) becomes { type : "Just", value: 10 }. >> >> The { ctor, _0, _1... _n } shape is, I assume, why we can't automatically >> send type values though ports. The rationale is: if it's really the reason, >> since we barely use more than one value in type values, why not facilitate >> port usage instead of larger type values. Does it makes sense at all? >> >> In other words, currently you can do that: >> >> type Foo = Foo | Bar Int Bool (String, Foo) >> where: Bar : Int -> Bool -> (String, Foo) -> Foo >> that you use like this in elm: Bar 1 False ("fooBar", Foo) >> which compiles down to in js: { ctor: "Bar", _0: 10, _1: false, _2: { ctor: >> "Tuple2", _0: "fooBar", _1: { ctor: "Foo"} } } >> >> It would become impossible, because the type value Bar has 3 values. >> Instead, you would have to give only one value to the Bar constructor : >> >> type Foo = Bar { id: Int, isSomething: Bool, foo: (String, Foo) } >> where: Bar : { id: Int, isSomething: Bool, foo: (String, Foo) } -> Foo >> that you would use like this: Bar { id = 0, isSomething = False, foo = >> ("fooBar", Foo) } >> would compiles down to: { type: "Bar", value: { id: 0, isSomething: false, >> foo: ["fooBar", { type: "Foo" }] } } >> >> The record could be as well replaced by a Tuple ( Int, Bool, (String, Foo) ) >> >> I hope it's clearer enough? >> >> On Sunday, January 15, 2017 at 4:33:50 PM UTC+1, Duane Johnson wrote: >> I'm trying to see if I understand your suggestion correctly. >> >> So would an enumeration like this: >> >> type Msg >> = ClickedButton >> | EnteredAge value >> | EnteredHeight value >> >> become... >> >> type Msg = { action : String, value : String } >> >> ? >> >> I'm trying to figure out how you'd "authorize up to one value" in a >> situation like this, since the whole point of an enumeration is to allow >> multiple possibilities. >> >> Duane >> >> On Sun, Jan 15, 2017 at 6:59 AM, Maxime Dantec <[email protected] <>> wrote: >> Hi folks, >> >> The last 3 versions of elm were somewhat unusual for a young programing >> language: features were removed and it has been simplified, to the point >> that you can't remove anything else. Well, about that. >> >> I believe that the last thing that could be simplified still are ADT. No >> type value has more than one value in the core repository, with the >> exception of Dict and Color. I have used a few types with more than one >> value myself, but I hardly see the difference with a type value that has 3 >> values and a type value that has a tuple3 as unique value, if you except the >> constructor signature. Does yourself make an intensive usage of this feature? >> >> So here is my suggestion: Why not authorize up to one value to type values? >> If you need to bundle values, you can still use a tuple or a record. The >> reasoning behind this, is to get rid of the _0, _1, _2 in the "native" part >> of the type values. we could have {ctor:"Enum"} or {ctor:"TypeValue", value: >> {...}}, and why not automatic serializer/deserializers in the ports thanks >> to this too? >> >> Everyone has an opinion, and it's very easy to make a suggestion while not >> implementing it. I'm not pretending that this is a good idea, I humbly think >> that it's worth mentioning given that it's in the scope of simplifying the >> language. Please share you opinion :) >> >> Cheers! >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Elm Discuss" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Elm Discuss" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > -- > You received this message because you are subscribed to the Google Groups > "Elm Discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. 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