Re: [Ur] Browser-based adventure game
> fun render (sgs : source gameState) : signal xbody = Thanks! I changed the function as you suggested. -Michael ___ Ur mailing list Ur@impredicative.com http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
Re: [Ur] Browser-based adventure game
Hi Saulo, Here are some points of doubt: - What is the type of a function that produces arbitrary HTML snippets. Is xbody correct? - What is the name of "show" and "eq" functions? I used "show_list", "show_gameState", "show_pair", and "eq_pair" instead of just "show" and "eq". Is this correct? - Is there a more convenient syntax for list construction than "1 :: 2 :: 3 :: []", something like "[1, 2, 3]"? - I had to pass both a "gameState" and a "source gameState" parameter to the "render" function (for the same game state). Is there a way around that? - I minimized the use of mutable data. So when the game state changes much of the page gets updated. This should probably be done in a more fine-grained way in reality. - Does Ur/Web do tail-call optimization? - Will there be other collections beyond lists (dictionary/map, array)? Best, Michael > On 12 Oct 2016, at 16:27, Saulo Araujo <sau...@gmail.com> wrote: > > Hi Michael, > > Thanks for sharing your game with the community. I skimmed its source code > and I did not found anything that I would qualify as a non-canonical use of > Ur/Web. However, beware that I am an Ur/Web beginner too :) Maybe you can > pinpoint which parts of the code you are afraid are non-canonical uses of the > language... > > Sincerely, > Saulo > > On Wed, Oct 12, 2016 at 8:33 AM, Michael Rohs > <michael.r...@hci.uni-hannover.de> wrote: > Hi, > > As part of my exploration of Ur/Web I wrote a tiny browser-based adventure > game. > > https://github.com/mirohs/urweb-adventure > > It might be helpful to others looking at the language. If you find > non-canonical use of the language (I guess there is some...), please let me > know. > > Cheers, > Michael > > > ___ > Ur mailing list > Ur@impredicative.com > http://www.impredicative.com/cgi-bin/mailman/listinfo/ur > > ___ > Ur mailing list > Ur@impredicative.com > http://www.impredicative.com/cgi-bin/mailman/listinfo/ur ___ Ur mailing list Ur@impredicative.com http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
[Ur] Browser-based adventure game
Hi, As part of my exploration of Ur/Web I wrote a tiny browser-based adventure game. https://github.com/mirohs/urweb-adventure It might be helpful to others looking at the language. If you find non-canonical use of the language (I guess there is some...), please let me know. Cheers, Michael ___ Ur mailing list Ur@impredicative.com http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
Re: [Ur] int to string?
Oh, I see.
Thanks!
-Michael
> On 09 Oct 2016, at 13:38, Saulo Araujo <sau...@gmail.com> wrote:
>
> Hi Michael,
>
> I believe that happens because the module List binds a function to the show
> variable:
>
> val show = fn [a] (_ : show a) =>
> let
> fun show' (ls : list a) =
> case ls of
> [] => "[]"
> | x :: ls => show x ^ " :: " ^ show' ls
> in
> mkShow show'
> end
>
> Therefore, opening the List module shadows the show function defined in the
> Basis module.
>
> val show : t ::: Type -> show t -> t -> string
>
> Regards,
> Saulo
>
>
>
> On Sun, Oct 9, 2016 at 6:55 AM, Michael Rohs
> <michael.r...@hci.uni-hannover.de> wrote:
> Hi Saulo,
>
> Thanks for your help. Thanks for the suggestion to add type annotations. It
> indeed works, but only if I don't open the List module.
>
> The problem appears if I add module List (even without using any of its
> functions).
>
> test.urp:
> $/list
> test
>
> test.ur:
> open List
>
> if I remove "open List" from test.ur it works.
>
> I don't understand why...
>
> Here is the full test.ur:
> --
> (*open List*) <-- error if uncommenting this line
>
> fun int2string (i : int) : string = show i
> val s = int2string 123
>
> fun main () =
> let
> val stuff = "apple" :: "key" :: "goat" :: []
> fun predicate (s : string) : bool = s <> "apple"
> (* val stuff2 = List.filter predicate stuff*)
> in
> return
> {[s]}
>
>
> end
> --
>
> Best,
> Michael
>
>
> > On 09 Oct 2016, at 10:04, Saulo Araujo <sau...@gmail.com> wrote:
> >
> > Hi Michael,
> >
> > Your definition of int2string is fine. For example, the code
> >
> > fun int2string (i : int) : string = show i
> >
> > val s = int2string 10
> >
> > compiles without errors. I suspect the problem is in another part of your
> > code. The error message suggests that you have an expression that produces
> > a list where something else is expected. In my experience learning
> > languages of the ML family, in situations like this, it helps to
> > type-annotate arguments and results of functions. Eventually, it also helps
> > to type-annotate expressions. For example
> >
> > val h = 10
> > val t = []
> > val s = (h :: t) : int
> >
> > Thanks to the type annotation ": int", the compiler will produce an error
> > saying that there is a list int where an int is required:
> >
> > Expression: Basis.Cons [int] {1 = h, 2 = t}
> > Have con: list int
> > Need con: int
> > Incompatible constructors
> > Have: list int
> > Need: int
> >
> > Regards,
> > Saulo
> >
> > On Sun, Oct 9, 2016 at 4:07 AM, Michael Rohs
> > <michael.r...@hci.uni-hannover.de> wrote:
> > Hi all,
> >
> > I have a question to a very simple problem. How to convert an integer to a
> > string?
> >
> > This does not work:
> >
> > fun int2string (i : int) : string = show i
> >
> > Error message:
> >
> > /.../test.ur:19:36: (to 19:40) Unification failure
> > Expression: show [] _
> > Have con: show (list )
> > Need con: ->
> > Incompatible constructors
> > Have: show (list )
> > Need: ->
> >
> > I couldn't find anything else like Int.toString or so.
> >
> > Thank you very much in advance!
> >
> > Best,
> > Michael
> >
> >
> > ___
> > Ur mailing list
> > Ur@impredicative.com
> > http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
> >
> > ___
> > Ur mailing list
> > Ur@impredicative.com
> > http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
>
>
> ___
> Ur mailing list
> Ur@impredicative.com
> http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
>
> ___
> Ur mailing list
> Ur@impredicative.com
> http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
___
Ur mailing list
Ur@impredicative.com
http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
Re: [Ur] int to string?
Hi Saulo,
Thanks for your help. Thanks for the suggestion to add type annotations. It
indeed works, but only if I don't open the List module.
The problem appears if I add module List (even without using any of its
functions).
test.urp:
$/list
test
test.ur:
open List
if I remove "open List" from test.ur it works.
I don't understand why...
Here is the full test.ur:
--
(*open List*) <-- error if uncommenting this line
fun int2string (i : int) : string = show i
val s = int2string 123
fun main () =
let
val stuff = "apple" :: "key" :: "goat" :: []
fun predicate (s : string) : bool = s <> "apple"
(* val stuff2 = List.filter predicate stuff*)
in
return
{[s]}
end
--
Best,
Michael
> On 09 Oct 2016, at 10:04, Saulo Araujo <sau...@gmail.com> wrote:
>
> Hi Michael,
>
> Your definition of int2string is fine. For example, the code
>
> fun int2string (i : int) : string = show i
>
> val s = int2string 10
>
> compiles without errors. I suspect the problem is in another part of your
> code. The error message suggests that you have an expression that produces a
> list where something else is expected. In my experience learning languages of
> the ML family, in situations like this, it helps to type-annotate arguments
> and results of functions. Eventually, it also helps to type-annotate
> expressions. For example
>
> val h = 10
> val t = []
> val s = (h :: t) : int
>
> Thanks to the type annotation ": int", the compiler will produce an error
> saying that there is a list int where an int is required:
>
> Expression: Basis.Cons [int] {1 = h, 2 = t}
> Have con: list int
> Need con: int
> Incompatible constructors
> Have: list int
> Need: int
>
> Regards,
> Saulo
>
> On Sun, Oct 9, 2016 at 4:07 AM, Michael Rohs
> <michael.r...@hci.uni-hannover.de> wrote:
> Hi all,
>
> I have a question to a very simple problem. How to convert an integer to a
> string?
>
> This does not work:
>
> fun int2string (i : int) : string = show i
>
> Error message:
>
> /.../test.ur:19:36: (to 19:40) Unification failure
> Expression: show [] _
> Have con: show (list )
> Need con: ->
> Incompatible constructors
> Have: show (list )
> Need: ->
>
> I couldn't find anything else like Int.toString or so.
>
> Thank you very much in advance!
>
> Best,
> Michael
>
>
> ___
> Ur mailing list
> Ur@impredicative.com
> http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
>
> ___
> Ur mailing list
> Ur@impredicative.com
> http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
___
Ur mailing list
Ur@impredicative.com
http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
[Ur] int to string?
Hi all, I have a question to a very simple problem. How to convert an integer to a string? This does not work: fun int2string (i : int) : string = show i Error message: /.../test.ur:19:36: (to 19:40) Unification failure Expression: show [] _ Have con: show (list ) Need con: -> Incompatible constructors Have: show (list ) Need: -> I couldn't find anything else like Int.toString or so. Thank you very much in advance! Best, Michael ___ Ur mailing list Ur@impredicative.com http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
[Ur] ListEdit Demo
Hi, listEdit is one of the demos. Looking through it I was surprised that these lines in the add function head' <- get head; case head' of Nil => set head cons | _ => return () are necessary. I changed them to return () and it still works, as I expected, so the relevant part becomes in set tail cons; set tailP tail'; return () end Is this correct or am I missing something? Best, Michael ___ Ur mailing list Ur@impredicative.com http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
