[Ur] Regular expressions DSEL?

[Artyom Shalkhakov]

Adam,

2017-02-28 21:02 GMT+06:00 Adam Chlipala <adamc at csail.mit.edu>:
>
> The easiest solution I found is to add this directive to test.urp: monoInline 10
>
> Short rationale: the compiler uses conservative program analysis to find opportunities to get rid of first-class functions.  Uses of the [transaction] monad are compiled internally into first-class functions, so we need to get rid of all their first-classness, as the compiler for server-side code currently doesn't support functions at runtime.  Extra inlining can help reveal more structure to the program analysis, and it did so in this case.
>

It seems to work now, and I don't have time to wade deeper into the
issue. Thank you.

> On 02/27/2017 11:22 AM, Artyom Shalkhakov wrote:
>
> Hello all,
>
> So I hit a road-block, the code:
>
> > fun groups (): transaction page =
> >  m <- return ((Tregex.match'
> >    (concat (literal "a") (capture [#X] (literal "b"))) "ab")
> >    : option {Whole:counted_substring, Groups:{X:counted_substring}});
> >  case m of
> >    None => return <xml>Failed: mismatch!</xml>
> >  | Some {Whole = whole, Groups = {X = {Start=s,Len=l}}} => return <xml>Success? Whole match: {[whole.Start]} + {[whole.Len]}, group is {[s]} + {[l]}</xml>
>
> Gives this error:
>
> > .../test.ur:137:17: (to 139:7) Anonymous function remains at code generation
> > Function:
> > (fn _ : {} =>
> >   (case UNBOUND_1 of
> >     None => write("Failed: mismatch!") |
> >      Some {Whole = whole, Groups = {X = {Start = s, Len = l}}} =>
> >       (write("Success? Whole match: ");
> >        (FFI(Basis.htmlifyInt_w(whole.Start));
> >         (write(" + ");
> >          (FFI(Basis.htmlifyInt_w(whole.Len));
> >           (write(", group is ");
> >            (FFI(Basis.htmlifyInt_w(s));
> >             (write(" + "); FFI(Basis.htmlifyInt_w(l)))))))))))
>
> To reproduce, you'll have to build urweb-regex (I've put some directions into README in my branch) and then do [cd tests && make all]
>
> What can be done to avoid this issue? I tried to put type annotations, didn't work.
>
> 2017-02-25 9:30 GMT+06:00 Artyom Shalkhakov <artyom.shalkhakov at gmail.com>:
>>
>> Hello all,
>>
>> 2017-02-23 21:55 GMT+06:00, Artyom Shalkhakov <artyom.shalkhakov at gmail.com>:
>> > Hello Benjamin, Ziv,
>> >
>> > I wrote a very rough approximation to the idea that Ziv proposed, here's
>> > the code (currently, it does not do much):
>> >
>> > https://github.com/ashalkhakov/urweb-regex/tree/typed-regex
>> >
>> > At first I was thinking that it would be better to introduce named groups,
>> > but now I'm wondering how to handle positional groups, instead?
>> >
>> > Tangentially, I also noticed that JS does not handle capture groups mixed
>> > with repetition, e.g.
>> >
>> > 'xabxabxab'.match(/(xab){3}/) // or with /(xab)*/
>> >
>> > gives: ["xabxabxab", "xab"] (would it be worth it to try to rule out cases
>> > like this statically? probably not?)
>> >
>>
>> I guess I figured it out. The idea is to keep track of index for every
>> group as well as the total count of groups in a regular expression.
>> Then, when constructing a capture:
>>
>> > capture [#Name] E
>>
>> the group indexes in E get incremented by 1, a new group is added:
>> {Name=0}, and the total count of groups is increased by 1.
>>
>> Similarly, when concatenating two expressions in
>>
>> > concat E1 E2
>>
>> the group indexes in E2 will all get incremented by N, where N is the
>> count of groups of E1.
>>
>> I think it should work.
>>
>> >
>> > 2017-02-21 21:21 GMT+06:00 Benjamin Barenblat <bbaren at mit.edu>:
>> >
>> >> On Mon, Feb 20, 2017 at 10:27 PM, Artyom Shalkhakov
>> >> <artyom.shalkhakov at gmail.com> wrote:
>> >> > Thank you for the pointer. I guess creating a new package that depends
>> >> > on
>> >> > urweb-regex is the way to go.
>> >>
>> >> I’m also happy to merge changes to urweb-regex. I think a richly-typed
>> >> API like the one you’re looking for would be quite valuable in the
>> >> regex library.
>> >>
>> >> _______________________________________________
>> >> Ur mailing list
>> >> Ur at impredicative.com
>> >> http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
>> >>
>> >
>> >
>> >
>> > --
>> > Cheers,
>> > Artyom Shalkhakov
>> >
>>
>>
>> --
>> Cheers,
>> Artyom Shalkhakov
>
>
>
>
> --
> Cheers,
> Artyom Shalkhakov
>
>
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>
>
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>



-- 
Cheers,
Artyom Shalkhakov