ats-lang-users — A mailing list for ATS users

[ats-lang-users] ATS2-0.2.7 released

[Hongwei Xi <hw...@bu...>]

Hi,

I am glad to announce the release of ATS2-0.2.7.

This is the 30th release of ATS2, the successor of the
ATS (currently referred to as ATS1) programming language. The
compiler for ATS2 is given the name ATS/Positats, ATS2/Postiats
or simply Postiats.

######

The official website for ATS is:

http://www.ats-lang.org

ATS-Postiats is hosted at github:

https://github.com/githwxi/ATS-Postiats

Major releases of ATS2 are available at:

https://sourceforge.net/projects/ats2-lang/

Major releases of external packages for ATS2 are available at:

https://sourceforge.net/projects/ats2-lang-contrib/

A google-group for discussing ATS and related issues is at:

https://groups.google.com/forum/?fromgroups#!forum/ats-lang-users

######

The following packages are included in this release:

ATS2-Postiats-0.2.7.tgz # requiring libgmp
ATS2-Postiats-contrib-0.2.7.tgz # contributed packages
ATS2-Postiats-include-0.2.7.tgz # CATS-files w/ BSD-like license

I have included ATS2-Postiats-contrib (instead of releasing it
separately) as it is truly by now an indispensible part of ATS2.

After installing ATS-Postiats-include, one can compile the C code
generated from ATS source without installing the ATS compiler. So
a convenient way to distribute software written in ATS is to simply
release the C code generated from the ATS source.

See below for some major additions and changes since the last release
(ATS2-0.2.6).

######

Cheers,

--Hongwei Xi

Computer Science Department
Boston University
111 Cummington Street
Boston, MA 02215

Email: hw...@cs...
Url: http://www.cs.bu.edu/~hwxi
Tel: +1 617 358 2511 (office)
Fax: +1 617 353 6457 (department)

######

1. Adding some basic functions into libats/ML/stdlib
2. Atexting is functioning; it has been used to syntax-hilite ATS code
    in docbook.
3. Refactoring libatsynmark to make it directly dependent on libatsopt
4. Automatically building libatsopt and libatsynmark when testing (travis-ci)
5. Automatically building INT2PROGINATS and ATS2TUTORIAL (thanks to Kiwamu Okabe)
6. Fixing bug-2016-05-13 involving pattern matching (see BUGs/bug-2016-05-13.dats)

[ats-lang-users] ATS2-0.2.6 released

[Hongwei Xi <hw...@bu...>]

Hi,

I am glad to announce the release of ATS2-0.2.6.

This is the 29th release of ATS2, the successor of the
ATS (currently referred to as ATS1) programming language. The
compiler for ATS2 is given the name ATS/Positats, ATS2/Postiats
or simply Postiats.

######

The official website for ATS is:

http://www.ats-lang.org

ATS-Postiats is hosted at github:

https://github.com/githwxi/ATS-Postiats

Major releases of ATS2 are available at:

https://sourceforge.net/projects/ats2-lang/

Major releases of external packages for ATS2 are available at:

https://sourceforge.net/projects/ats2-lang-contrib/

A google-group for discussing ATS and related issues is at:

https://groups.google.com/forum/?fromgroups#!forum/ats-lang-users

######

The following packages are included in this release:

ATS2-Postiats-0.2.6.tgz # requiring libgmp
ATS2-Postiats-contrib-0.2.6.tgz # contributed packages
ATS2-Postiats-include-0.2.6.tgz # CATS-files w/ BSD-like license

I have included ATS2-Postiats-contrib (instead of releasing it
separately) as it is truly by now an indispensible part of ATS2.

After installing ATS-Postiats-include, one can compile the C code
generated from ATS source without installing the ATS compiler. So
a convenient way to distribute software written in ATS is to simply
release the C code generated from the ATS source.

See below for some major additions and changes since the last release
(ATS2-0.2.5).

######

Cheers,

--Hongwei Xi

Computer Science Department
Boston University
111 Cummington Street
Boston, MA 02215

Email: hw...@cs...
Url: http://www.cs.bu.edu/~hwxi
Tel: +1 617 358 2511 (office)
Fax: +1 617 353 6457 (department)

######

Here is a list of major additions and changes since the last release:

1. A minor fix to make the long form of macrodef work
2. Adding an article in EFFECTIVATS on parsing combinators of CPS-style
3. Allowing recursive evaluation of a file path: pkgsrcname_eval
4: Adding a section on linear C-strings in INT2PROGINATS
5: Adding an ATS2TUTORIAL-chapter on stack-allocated closure-functions
6: Adding support for #pragma(location, ...) (referred to as locpragma)
7. Adding an article in EFFECTIVATS on imperative vs. functional vs. linear functional

[ats-lang-users] ATS2-0.2.5 released

[Hongwei Xi <hw...@bu...>]

Hi,

I am glad to announce the release of ATS2-0.2.5.

This is the 28th release of ATS2, the successor of the
ATS (currently referred to as ATS1) programming language. The
compiler for ATS2 is given the name ATS/Positats, ATS2/Postiats
or simply Postiats.

######

The official website for ATS is:

http://www.ats-lang.org

ATS-Postiats is hosted at github:

https://github.com/githwxi/ATS-Postiats

Major releases of ATS2 are available at:

https://sourceforge.net/projects/ats2-lang/

Major releases of external packages for ATS2 are available at:

https://sourceforge.net/projects/ats2-lang-contrib/

A google-group for discussing ATS and related issues is at:

https://groups.google.com/forum/?fromgroups#!forum/ats-lang-users

######

The following packages are included in this release:

ATS2-Postiats-0.2.5.tgz # requiring libgmp
ATS2-Postiats-contrib-0.2.5.tgz # contributed packages
ATS2-Postiats-include-0.2.5.tgz # CATS-files w/ BSD-like license

I have included ATS2-Postiats-contrib (instead of releasing it
separately) as it is truly by now an indispensible part of ATS2.

After installing ATS-Postiats-include, one can compile the C code
generated from ATS source without installing the ATS compiler. So
a convenient way to distribute software written in ATS is to simply
release the C code generated from the ATS source.

See below for some major additions and changes since the last release
(ATS2-0.2.4).

######

Cheers,

--Hongwei Xi

Computer Science Department
Boston University
111 Cummington Street
Boston, MA 02215

Email: hw...@cs...
Url: http://www.cs.bu.edu/~hwxi
Tel: +1 617 358 2511 (office)
Fax: +1 617 353 6457 (department)

######

Here is a list of major additions and changes since the last release:

######

1. With libatscc2js(JS), Atscc2js can now run entirely inside the
    browser.
2. Patsopt(JS) and Atscc2js(JS) have been combined to allow one to
    try ATS entirely in one's browser (running only client-side JS).
3. Treating the following form as a value: let ... in aValue end
    (where aValue is assumed to be a value).
4. WebWorker-based support for session types in libatscc2js/Worker/channel
5. Fixing the handling of decarg of a function template declaration
6. Fixing a bug in effect-tracking of assignment: assigning a proof term
    should not genereate any effect. Please see: 
d2exp_trup_assgn:D2LVALvar_mut
7. Adding libats/ML/gvalue
8. Adding libats/ML/dynarray
9. Adding an ATS2TUTORIAL-chapter on boxed tuples and records.
10. Adding an article in EFFECTIVATS on encoding propositional logic
11. Removing the once planned support for flattened references (ref@)

Re: [ats-lang-users] How to use allocation out of POSIX?

[Kiwamu O. <ki...@de...>]

I make own prelude for the ESP8266 platform:

https://github.com/fpiot/esp8266-ats/tree/ats/ESP8266_PRELUDE
https://github.com/fpiot/esp8266-ats/blob/ats/Makefile.common#L42

The compile option is wrong?

```
ATSCFLAGS    += -D_ATSTYPE_VAR_SIZE_=0X000F
-D_ATS_CCOMP_EXCEPTION_NONE_ -D_ATS_CCOMP_RUNTIME_NONE_
-D_ATS_CCOMP_PRELUDE_NONE_
-D_ATS_CCOMP_PRELUDE_USER_=\"../../ESP8266_PRELUDE/kernel_prelude.cats\"
```
-- 
Kiwamu Okabe at METASEPI DESIGN

[ats-lang-users] How to use allocation out of POSIX?

[Kiwamu O. <ki...@de...>]

Hi all,

Now, I'm porting ATS programming environment into tiny chip named ESP8266.

  https://github.com/fpiot/esp8266-ats

And I'm trying to use strptr on the platform.

```
$ vi esp8266-ats/ESP8266_PRELUDE/CATS/memalloc.cats
#ifndef ATSLIB_PRELUDE_CATS_MEMALLOC
#define ATSLIB_PRELUDE_CATS_MEMALLOC

void atsruntime_mfree_undef (void *ptr) {
  os_free(ptr);
  return;
}
void *atsruntime_malloc_undef (size_t bsz) {
  return ((void *)os_malloc(bsz));
}

#endif // ifndef ATSLIB_PRELUDE_CATS_MEMALLOC
$ vi esp8266-ats/ESP8266_PRELUDE/kernel_prelude.cats
--snip--
#include "ESP8266_PRELUDE/CATS/memalloc.cats"
$ vi esp8266-ats/dweet_ats/user/user_main.dats
--snip--
implement tcp_connected (arg) = {
  val temperature = 55 (* test data *)
  val conn = $UN.cast{cPtr1(espconn_t)}(arg)

  val () = println! "tcp_connected()"
  val _  = espconn_regist_recvcb (conn, data_received)

  val json_data = string0_append ("{\"temperature\": ", "")
  val () = free json_data
--snip--
```

However the code occurs following compile error:

```
$ cd esp8266-ats/dweet_ats
$ make
ATS user/user_main.dats
CC build/user/user_main_dats.c
In file included from build/user/user_main_dats.c:15:0:
build/user/user_main_dats.c: In function
'ATSLIB_056_prelude__string1_append__5__1':
/home/kiwamu/src/ATS-Postiats/ccomp/runtime/pats_ccomp_instrset.h:266:35:
error: assignment makes pointer from integer without a cast [-Werror]
 #define ATSINSmove(tmp, val) (tmp = val)
                                   ^
build/user/user_main_dats.c:873:1: note: in expansion of macro 'ATSINSmove'
 ATSINSmove(tmp19__1, atspre_malloc_gc(tmp20__1)) ;
 ^
cc1: all warnings being treated as errors
../Makefile.common:146: recipe for target 'build/user/user_main_dats.o' failed
make: *** [build/user/user_main_dats.o] Error 1
rm build/user/user_main_dats.c
```

What's wrong?

On POSIX, following code is available:

```
#include "share/atspre_define.hats"
#include "share/atspre_staload.hats"

%{^
void atsruntime_mfree_undef (void *ptr) {
  free(ptr);
  return;
}
void *atsruntime_malloc_undef (size_t bsz) {
  return malloc(bsz);
}
%}

implement main0 () = {
  val json_data = string0_append ("{\"temperature\": ", "")
  val () = println! json_data
  val () = free json_data
}
```

Thanks,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to use extype on at-view?

[Kiwamu O. <ki...@de...>]

On Sat, Nov 14, 2015 at 9:46 PM, gmhwxi <gm...@gm...> wrote:
> There seems a misuse of quantifier:
>
> typedef dns_found_callback_t = {l:addr} (!ip_addr_t@l | string, ptr l, ptr)
> -> void

Fixed. Thanks.
BTW. How to understand following error message?

```
ATS user/user_main.dats
/home/kiwamu/src/esp8266-ats/dweet_ats/user/user_main.dats:
1022(line=32, offs=24) -- 1026(line=32, offs=28): error(3): the
dynamic expression cannot be assigned the type
[S2Eat(S2Etyrec(fltext(ip_addr_t); npf=-1; addr=S2Ecst(uint32)),
S2Evar(l$3144(7279)))].
/home/kiwamu/src/esp8266-ats/dweet_ats/user/user_main.dats:
1022(line=32, offs=24) -- 1026(line=32, offs=28): error(3): mismatch
of sorts in unification:
The sort of variable is: S2RTbas(S2RTBASimp(1; t@ype))
The sort of solution is: S2RTbas(S2RTBASimp(7; view))
```
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to use extype on at-view?

[Kiwamu O. <ki...@de...>]

On Sat, Nov 14, 2015 at 9:49 PM, gmhwxi <gm...@gm...> wrote:
> By the way, what is the type of dns_done_c?

extern fun dns_done_c: dns_found_callback_t = "mac#"
-- 
Kiwamu Okabe at METASEPI DESIGN

[ats-lang-users] How to use extype on at-view?

[Kiwamu O. <ki...@de...>]

Hi all,

I'm trying to make a function exported from C language.
ATS language side is following:

```
typedef dns_found_callback_t = [l:addr] (ip_addr_t@l | string, ptr l,
ptr) -> void
extern fun dns_done: dns_found_callback_t = "mac#"
implement dns_done (pfat | name, ipaddr, arg) = {
  val () = dns_done_c (pfat | name, ipaddr, arg) // <= Error occurs at here!
}
```

C language side is following:

```
void dns_done_c( const char *name, ip_addr_t *ipaddr, void *arg )
{
...
```

I believe the view will be removed after compile. However the code
can't be compiled.

```
$ make
ATS user/user_main.dats
/home/kiwamu/src/esp8266-ats/dweet_ats/user/user_main.dats:
1022(line=32, offs=24) -- 1026(line=32, offs=28): error(3): the
dynamic expression cannot be assigned the type
[S2Eat(S2Etyrec(fltext(ip_addr_t); npf=-1; addr=S2Ecst(uint32)),
S2Evar(l$3144(7279)))].
/home/kiwamu/src/esp8266-ats/dweet_ats/user/user_main.dats:
1022(line=32, offs=24) -- 1026(line=32, offs=28): error(3): mismatch
of sorts in unification:
The sort of variable is: S2RTbas(S2RTBASimp(1; t@ype))
The sort of solution is: S2RTbas(S2RTBASimp(7; view))
/home/kiwamu/src/esp8266-ats/dweet_ats/user/user_main.dats:
1022(line=32, offs=24) -- 1026(line=32, offs=28): error(3): mismatch
of static terms (tyleq):
The actual term is: S2EVar(1955)
The needed term is: S2Eat(S2Etyrec(fltext(ip_addr_t); npf=-1;
addr=S2Ecst(uint32)); S2Evar(l$3144(7279)))
```

How to use extype on at-view?

Thanks,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] [Slide] Static typing and proof on ATS language

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sun, Nov 8, 2015 at 12:36 AM, gmhwxi <gm...@gm...> wrote:
> I have a suggestion that you also make webpage-based slides.
> Then you can present your code "lively":
>
> http://ats-lang.github.io/EXPERIMENT/patsopt-atscc2js-trial/index.html
>
> This will allow people to easily try your code when reading your slides.
> They will be much more impressed in this way because they are able to
> experience first-handedly how program mistakes are caught as type-errors
> by the typechecker of ATS.

Thanks for your advice. I have many chance to explain ATS language for
beginners. The webpage is useful for it.

Thanks,
-- 
Kiwamu Okabe at METASEPI DESIGN

[ats-lang-users] [Slide] Static typing and proof on ATS language

[Kiwamu O. <ki...@de...>]

Hi all,

I made a slide to explain statics and proofs on ATS language.

  http://www.slideshare.net/master_q/static-typing-and-proof-on-ats-language

Could you check the following figures? > Hongwei
I may miss-understand it.

  http://www.slideshare.net/master_q/static-typing-and-proof-on-ats-language/9
  http://www.slideshare.net/master_q/static-typing-and-proof-on-ats-language/13
  http://www.slideshare.net/master_q/static-typing-and-proof-on-ats-language/16

Thanks,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@de...>]

On Tue, Oct 27, 2015 at 3:31 PM, Hongwei Xi <gm...@gm...> wrote:
>>>And, where is body of the static function?
>
> There is none.
>
> A stacst is not implemented in ATS. Instead, the meaning of a stacst is
> determined by the constraint-solver.

Why we can't implement static function using `sif` and `scase`?
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@de...>]

Hi Mike,
I'm also newbie.

On Oct 30, 2015 22:38, "Mike Jones" <pro...@gm...> wrote:
> What is stacst? (Static Cast?) is there some explanation of how it works?

The `stacst` introduce only signature of the static function. It doesn't
introduce body. If you use the static function, you also need to introduce
some hint for the constraint-solver.

https://github.com/jats-ug/practice-ats/blob/b408db3ffccad49a3f380987a2ecae88f62b2dbe/static_rps/rps.dats#L31

Please remove following lines and try to compile. You will see some
error on the constraint-solver.

```
prval () = rps_win_s_p_pf()
```

> Why is extern required for extern praxi in dats?

I think it has no body in the proof functions.

> I thought of proofs and statics as being tossed after compile, but it looks like you can execute them. I assume this practice is mainly for testing?

Sometime the code has both dynamics and proofs. For example, the
function `rps_win_s` has dynamics code and static interface.

https://github.com/jats-ug/practice-ats/blob/b408db3ffccad49a3f380987a2ecae88f62b2dbe/static_rps/rps.sats#L22

Also, the `rps_win_p` function has dynamics code and proof code.

https://github.com/jats-ug/practice-ats/blob/b408db3ffccad49a3f380987a2ecae88f62b2dbe/static_rps/rps.sats#L40

Dynamics code should be alive after compile, while statics and proofs
are deleted at the time. I think following slide is useful to understand it.

http://www.slideshare.net/master_q/atslf-for-coq-users/6

Thank's,

Re: [ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@gm...>]

On Oct 30, 2015 22:01, "Kiwamu Okabe" <ki...@de...> wrote:
> Which style is more better? Of course, the statics style is nonsense,

Sorry. I meaned "dynamics style is nonsense."

Re: [ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@de...>]

Hi all,

Finally, I defined the function in dynamics and statics, proofs.

https://github.com/jats-ug/practice-ats/tree/master/static_rps

Which style is more better? Of course, the statics style is nonsense,
because it should use exception. But my head think proofs style is
better.

How do you think? > all

Thanks,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Wed, Oct 28, 2015 at 12:24 PM, Hongwei Xi <gm...@gm...> wrote:
> Say you want to use rps_win(r, s) in your reasoning. You just do:
>
> prval () = rps_win_r_s() // adding rps_win(r, s) into the current pool of
> assumptions
>
> The constraint-solver simply treats rps_win like an unknown function symbol.

Also, I can define rps_even as following:

https://gist.github.com/master-q/a590dcf8f692e065c2e1#file-rps-dats-L89

> By the way, Z3 does a much better job in handling unknown function symbols.

I'm waiting the paper about Z3 on FLOPS.

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] ATS2-0.2.4 released

[Raoul D. <ra...@gm...>]

Congratulations! Keep it rolling.

[ats-lang-users] ATS2-0.2.4 released

[Hongwei Xi <hw...@bu...>]

Hi,

I am glad to announce the release of ATS2-0.2.4.

This is the 27th release of ATS2, the successor of the
ATS (currently referred to as ATS1) programming language. The
compiler for ATS2 is given the name ATS/Positats, ATS2/Postiats
or simply Postiats.

######

The official website for ATS is:

http://www.ats-lang.org

ATS-Postiats is hosted at github:

https://github.com/githwxi/ATS-Postiats

Major releases of ATS2 are available at:

https://sourceforge.net/projects/ats2-lang/

Major releases of external packages for ATS2 are available at:

https://sourceforge.net/projects/ats2-lang-contrib/

A google-group for discussing ATS and related issues is at:

https://groups.google.com/forum/?fromgroups#!forum/ats-lang-users

######

The following packages are included in this release:

ATS2-Postiats-0.2.4.tgz # requiring libgmp
ATS2-Postiats-contrib-0.2.4.tgz # contributed packages
ATS2-Postiats-include-0.2.4.tgz # CATS-files w/ BSD-like license

I have included ATS2-Postiats-contrib (instead of releasing it
separately) as it is truly by now an indispensible part of ATS2.

After installing ATS-Postiats-include, one can compile the C code
generated from ATS source without installing the ATS compiler. So
a convenient way to distribute software written in ATS is to simply
release the C code generated from the ATS source.

See below for some major additions and changes since the last release
(ATS2-0.2.3).

######

Cheers,

--Hongwei Xi

Computer Science Department
Boston University
111 Cummington Street
Boston, MA 02215

Email: hw...@cs...
Url: http://www.cs.bu.edu/~hwxi
Tel: +1 617 358 2511 (office)
Fax: +1 617 353 6457 (department)

######

Here is a list of major additions and changes since the last release:

######

1. Fixing a bug due to abstract types being given the 'empty' name.
2. Adding libats/theGetters
3. Fixing a bug in ATS-extsolve (involving the s2rtdatmap generation)
4. Fixing a minor parsing bug in CATS-parsemit
5. Adding libatsopt, the library version of patsopt; see utils/libatsopt
6. Adding some ifdef-guards:
    ATS_EXTERN_DEF__ for guarding the definition of ATSextern()
    ATS_STATIC_DEF__ for guarding the definition of ATSstatic()
    ATS_INLINE_DEF__ for guarding the definition of ATSinline()
7. Adding some examples to illustrate a way of using ATS+Emscripten
8. Supporting evaluated expressions (of the form %(...)) in statics
9. Generally improving libatscc2js and libatscc2erl
10. With libatsopt(JS), patsopt can now run entirely inside the browser.
11. Adding char2int1 and fixing add_bool_bool and mul_bool_bool

[ats-lang-users] Rock-paper-scissors library to learn statics and proofs on ATS language

[Kiwamu O. <ki...@de...>]

Hi all,

https://github.com/jats-ug/practice-ats/tree/master/static_rps

It's used as following:

```
implement main0 () = {
  val paper = p_rps_t()
  val (pf_win | win) = rps_win (paper)
  val () = println! (win, " win ", paper, ".") // => Scissors win Paper.
  val (_, _ | even) = rps_even (pf_win | win, paper)
  val () = println! (even, " even between ", win, " and ", paper, ".")
// => Rock even between Scissors and Paper.
}
```

The `rps_win` function returns a value that wins the argument.
The `rps_even` function returns a value that evens between the arguments.
ATS language prove these functions.

I have a question. Can I implement `rps_win` and `rps_even` functions
using static function?
I would like to implement them as following:

fun{} rps_win
  {r1:rps_s} (x: rps_t (r1)):
  [r2:rps_s | s_win(r2, r1)] (rps_t (r2))

Can I implement statics function such like `s_win`?

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to identify dynamic value such like bool?

[john s. <sk...@us...>]

> On 25 Oct 2015, at 00:50, gmhwxi <gm...@gm...> wrote:
> 
> Correct.
> 
> You can use ‘_ when ...' instead:

For that I use another shorthand:

	| (A, $constant) => …

translates to

	| (A, synthvar) when synthvar == constant => …


—
john skaller
sk...@us...
http://felix-lang.org

Re: [ats-lang-users] How to identify dynamic value such like bool?

[john s. <sk...@us...>]

> On 25 Oct 2015, at 00:07, gmhwxi <gm...@gm...> wrote:
> 
> 
> 'true' and 'false' are constants. They are treated specially when
> used as patterns.

That’s naughty! Here’s what I did:

1)  Felix originally copied Ocaml in having constant (no argument)
constructors. However I hate Camelcase. So I made the user do this:

	| Fred ?argument => …
	| Joe => …

2) This is ugly, having to put ? before variables.
So I changed it. I copied ATS :-) No constant constructors:

	| Fred argument => …
	| Joe () => …

3) Felix always had an abbreviation in expressions:

	#f ==> f ()

Its a shorthand which is very useful because in Felix type classes
you cannot have constants, only functions. So you have to do

	#zero[double] 

for example, for the real number class zero, instance double.

4) Hence:

	match .. with
	| #True => …
	| #False => …

5) In fact the parser translates true and false, they’re treated “special”
in the parser NOT in pattern matches. Having special things in core
parts of the compiler add complexity.

—
john skaller
sk...@us...
http://felix-lang.org

Re: [ats-lang-users] How to identify dynamic value such like bool?

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sat, Oct 24, 2015 at 10:50 PM, gmhwxi <gm...@gm...> wrote:
> You can use '_ when ...' instead:
>
> https://github.com/githwxi/ATS-Postiats-test/blob/master/contrib/hwxi/TEST20/test21.dats

Clear. I think I understand it.

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to identify dynamic value such like bool?

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sat, Oct 24, 2015 at 10:36 PM, gmhwxi <gm...@gm...> wrote:
> You can. You just cannot use them (r_rps, p_rps, s_rps)
> as patterns. Note that 'true' and 'false' are treated specially when
> used as patterns.

Hmm...

I can define constructors of rps.
I can use the constructors as patterns.
I can define constants of rps.
I can't use the constants as patterns.

Correct?

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to identify dynamic value such like bool?

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sat, Oct 24, 2015 at 10:22 PM, Kiwamu Okabe <ki...@de...> wrote:
> 'true' and 'false' are pre-defined constants?
> I can't find the definition in prelude?

Following is the definition of true?

https://github.com/githwxi/ATS-Postiats/blob/master/prelude/basics_dyn.sats#L59

Why my following code can't define the constants of rps?

https://github.com/jats-ug/practice-ats/blob/ce6d2001867fa4a9db6c3dc9fb2044d5346bfc6f/static_rps/rps.sats#L10

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to identify dynamic value such like bool?

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sat, Oct 24, 2015 at 10:07 PM, gmhwxi <gm...@gm...> wrote:
> 'true' and 'false' are constants. They are treated specially when
> used as patterns.
>
> On Saturday, October 24, 2015 at 8:58:22 AM UTC-4, Kiwamu Okabe wrote:
>> Where is the constructor of true and false?

'true' and 'false' are pre-defined constants?
I can't find the definition in prelude?

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN

Re: [ats-lang-users] How to identify dynamic value such like bool?

[Kiwamu O. <ki...@de...>]

Hi Hongwei,

On Sat, Oct 24, 2015 at 9:34 PM, gmhwxi <gm...@gm...> wrote:
> r_rps is not a constructor and thus cannot be used as a pattern
> (the compiler treats it as a variable that matches any value)
>
> Try:
>
> datatype rps(rps) = r_rps(r_rps) | p_rps(p_rps) | s_rps(s_rps)
>
> Then you can use r_rps() as a pattern.

Fixed my code.

https://github.com/jats-ug/practice-ats/commit/c2b7d57abbde3a0a7f68173179bd2db2f069521c

Where is the constructor of true and false?

Thank's,
-- 
Kiwamu Okabe at METASEPI DESIGN