
Picat – A new logic-based programming language - callmekit
http://picat-lang.org/
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joe_the_user
Looks like an interesting project.

The license or terms-of-use seem weird: _" Picat can be used for any fair
purpose, including commercial applications. The C source code is available to
registered developers and users free of charge. The project is open to anybody
and you are welcome to join, as a developer, a sponsor, a user, or a reviewer.
Please contact picat@picat-lang.org"_

Why make things complicated with these conditions? If you are going to allow
source access, why not use a standard open source license. If you aren't, if
you want to control of the language for some purpose, make it clear this is a
commercial product.

The GPL (and other standard open source licenses) are a real commercial
licenses at this point. Roll-your-own software licenses seem a lot like roll-
your-own device device drivers - might have made sense in yesterday's world
but not today.

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lfowles
From [1]:

The Picat C-source code is distributed under the Mozilla Public License
([http://mozilla.org/MPL/2.0/](http://mozilla.org/MPL/2.0/)). You are assumed
to agree to the terms and conditions as described in the license if you submit
this request. Please provide a valid email address.

[1]:
[https://docs.google.com/forms/d/188dDBVrNrrshZtO8smEBgskOrMl...](https://docs.google.com/forms/d/188dDBVrNrrshZtO8smEBgskOrMlCxhXGM6fvfhwDImo/viewform)

~~~
joe_the_user
Well good then. It still seems silly to have the text I quoted on the main
page - especially since someone who'd loaded the code is then legally free
redistribute it without requiring registration or an email address.

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agumonkey
Here's an article explaining it's features with more mainstream terms.

[http://www.hakank.org/constraint_programming_blog/2013/09/a_...](http://www.hakank.org/constraint_programming_blog/2013/09/a_first_look_at_picat_programming_language_1.html)

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joe_the_user
Another language which involves both constraint programming and imperative
programming is Alma-0[1]. While Alma-0 doesn't seem that much more than a toy
language, I always liked the backtracking + standard-loops feature. It seemed
offer clarity plus incredible power.

I would wonder if Picat has similar feature (to implicit backtracking in
imperative loops)?

[1] [http://en.wikipedia.org/wiki/Alma-0](http://en.wikipedia.org/wiki/Alma-0)

~~~
callmekit
Yes, ideas behind Alma-0 look similar to the ones behind Picat.

Loops in Picat are compiled to recursive calls. And there is automatic
backtracking, like in Prolog.

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memming
I used to love Prolog, but Prolog is not general purpose. This has 'pi',
'cat', some imperative, and prolog taste in it...most interesting.

