DES 4.2 Released

[Fernando Sáenz Pérez]

[Apologies for multiple receptions]

Hello.
This is a mail just for informing that the new release

Datalog Educational System version 4.2
http://des.sourceforge.net

has been launched on September, 25th, 2016, and tested for

SICStus Prolog 4.3.1
SWI-Prolog 7.2.3

The current version mainly benefits from two enhancements:
First, data types for date and time have been included,
together with a bunch of predicates, operators and functions
for dealing with them, both in Datalog and SQL. And second,
following the addition of these new data types, evaluable
expressions have been revisited for including types other
than arithmetic types. Operators admit overloading for
polymorphic typing. For instance, addition (+) and
subtraction (-) operators can range on date and numeric
types for computing a date displacement. Other additions
include a type casting function and predicate, that have
been added to explicitly convert values to other types, in
addition to the already available automatic type casting.
Also, lexicons for DRC and TRC have been included.

A complete list of enhancements and fixed bugs is attached
to the end of this message.
Please, see http://des.sourceforge.net for details.

Best regards.



=============================================================
Fernando Saenz Perez
Profesor Titular de Universidad / Associate Professor
Home Page: http://www.fdi.ucm.es/profesor/fernan
Tel: + 34 913947642. Fax: + 34 913947547
Despacho / Office: 435 (4ª planta / 4th floor)
Dept. Ingenieria del Software e Inteligencia Artificial /
Department of Software Engineering and Artificial
Intelligence
Universidad Complutense de Madrid
Facultad de Informatica
C/Profesor Jose Garcia Santesmases, s/n
E - 28040 Madrid. Spain

=============================================================



Version 4.2 of DES (released on September, 25th, 2016)

* Enhancements:
o Date and time-related data types date, time and datetime
(also timestamp following standard SQL) for relations
(Datalog and SQL)
o Evaluable expressions (in both Datalog and SQL) also
support string and date/time/datetime types (evaluable
expressions were only arithmetic up to previous version)
o Built-in Datalog predicates for string handling
($concat/3, $length/2, $like/2, $like/3, $lower/2,
$substr/4, $upper/2)
o Built-in Datalog predicates for date/time/datetime
handling ($year/2, $month/2, $day/2, $current_date/1,
$current_time/1, $current_timestamp/1)
o Functions and operators for string handling (concat,
length, like-escape, lower, substr, upper, ||, +)
o Functions for date/time/datetime handling (year, month,
day, hour, minute, second, current_time, current_date,
current_datetime).
o The SQL standard function extract is also available (for
SQL, RA, TRC and DRC), which extracts the value of the
given field from a date/time/timestamp value
o Overloading for the operators +, - which can be applied
to number, string, and date/time/timestamp types
o Comparison operators also range on date and time values
o Time and date value inputs are normalized
o Datalog and SQL date, time and timestamp constants as,
e.g.:
- date(2016,08,31) and DATE '2016-08-31', both
representing August 31st 2016 for Datalog and SQL
respectively
- time(18,30,44) and TIME '18:30:44', in 24 hour format
for the same time for Datalog and SQL respectively
- datetime(2016,08,31,18,30,44) , DATETIME '2016-08-31
18:30:44', TIMESTAMP '2016-08-31 18:30:44', all three
representing the same timestamp (first one for Datalog
and the others for SQL)
o Function (cast) and predicate ('$cast'/3) for type
casting between appropriate types
o Added an ACIDE lexicon for DRC and TRC
o New SQL DDL statement CREATE TABLE Name AS Statement
o Added trunc as a synonym for truncate


* Fixed bugs:
o Some exceptions did not clear the asserted answer rules
o Evaluating a compound arithmetic expression of a
variable bound to a null failed for aggregates providing
this value




//------------------------------//
// ACIDE 0.17 Release Notes //
// September, 10th 2015 //
//------------------------------//


* Enhancements, changes and fixed bugs:
o Localization to French
o Multiple editors for new files
o New Reset and Refresh buttons for the Database panel
o The Datalog query for Trace Datalog becomes single-lined
o Keyboard shortcut (F9) for Play
o Rule (SQL statement, resp.) location becomes disabled
by-default in Trace Datalog (Trace SQL, resp.)
o New Debug SQL panel but with incomplete functionality
o Bug fixes in several panels (Console, Database, ...) but
presumably others added.


IMPORTANT CAVEATS / KNOWN BUGS:
o Ctrl+Mouse Wheel for resizing font display may take long
time depending on the number of open file editors.
o Opening medium-sized text files may take long time due
to lexical analysis. No progress indicators are provided.
Only when all editor windows are processed they are
displayed.
o As an alpha version, there are expected many bugs and
incomplete functionalities. Please report them to
fer...@sip.ucm.es