[Ur] Few bugs, questions and feature requests

Sun Nov 22 15:38:51 EST 2009

Isn't it time to set up Ur issue tracker?

Kind regards,
Kirill Zaborsky

2009/11/22 Vladimir Shabanov <vshabanoff at gmail.com>:
> First of all thanks for nice language, played with it for a some time
> and here are some bug reports & questions.
> __________
>
> When there is a form and no .urs-file Ur gives strange error:
> ":0:0-0:0: Function needed for both a link and a form"
>
> somemodule.ur:
> fun main () : transaction page = return <xml>
>  <body>
>    <form>
>      <textbox{#Text}/><submit action={submit}/>
>    </form>
>  </body>
> </xml>
>
> and submit r = return <xml/>
>
> When I add somemodule.urs (even the empty one) error disappear.
> I took me about a hour to determine source of problem since error
> message is quite undescriptive.
> __________
>
> Empty tags pair gives "syntax error: deleting  BEGIN_TAG GT END_TAG":
> fun main () = return <xml><body>
>  <div></div>
> </body></xml>
>
> Nested empty tags pairs gives additional "syntax error found at XML_END":
> fun main () = return <xml><body>
>  <div><div></div></div>
> </body></xml>
>
> This is fixed by adding spaces between tags, but still I don't think
> this is an error.
> __________
>
> When I try to add some attributes to html tags I get "Couldn't prove
> field name disjointness" error:
> fun main () = return <xml><body><table>
>  <tr> <td align="right">#</td> <td>123</td> </tr>
> </table></body></xml>
>
> As I understand Ur currently doesn't support html tag attributes
> (except 'style' which is handled specially). But instead something
> like "attributes doesn't supported, try CSS styles" error, Ur display
> error which is related to record fields which is quite confusing.
> __________
>
> I get "Couldn't prove field name disjointness" for such code:
> fun row (label : string) = <xml>
>  <div> {[label]} </div>
> </xml>
> fun main () = return <xml/>
>
> And "Some constructor unification variables are undetermined in
> declaration" for this one:
> fun row (label : string) = <xml>
>  {[label]}
> </xml>
> fun main () = return <xml/>
>
> Making "main () = return (row "asdf")" cures second case but not the first.
>
> I get the same errors with xml "label".
> __________
>
> "<label>" tag gives "Unbound expression variable label".
> How can I make something like:
> <checkbox{#Keep}/><label for={#Keep}>Keep me signed in</label>
> __________
>
> When Ur compilation is failed it doesn't return error code (so 'make'
> doesn't stops).
> __________
>
> Can the clearCookie be added? "cookie c : option {..}" & "setCookie c
> None" works ok, but it took some time to figure it out.
> __________
>
> How can I setup cookie expire time?
> __________
>
> Why the () argument is used for 'transaction page' functions?
> For people with Haskell background it looks quite unnecessary.
>
> I've changed 'fun page () = ...' to 'val page = ...' and it works for
> links, but not works when I point my browser to Module/page directly.
> I would be nice to allow to not write superfluous unit argument for
> monadic pages.
>
> Also why there are 'let', 'fun' and 'val'? In ocaml any function/value
> is written using 'let'. I think this syntax is more uniform.
> __________
>
> Sometimes I see in console "Error triggers unlimited retry: Couldn't
> allocate new heap chunk contiguously". What does it mean? Program
> continues to work after this error.
>
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