how to / exemple for using CIAO with unicode contents

[o***@mailoo.org]

Hi

I am searching for exemples for using CIAO Prolog with unicode contents.


Are they possible in atoms and variables or only in variables?

How to elaborate unicode contents for HTML?

Is there somewhere a bibliothek online for Proloog applications using
both?

Kind regards

[Jose F. Morales]

Post by o***@mailoo.org
Hi
I am searching for exemples for using CIAO Prolog with unicode contents.
Are they possible in atoms and variables or only in variables?
How to elaborate unicode contents for HTML?
Is there somewhere a bibliothek online for Proloog applications using both?

Hi,

You can use Unicode characters (UTF-8) in the code as long as it is
part of a string or a quoted atom. For example, the following code is
valid:

p(Z) :- X = '☆'('☀ ☆ ☂'), Y = '☆'(Z), X=Y.

q(Z) :- X = '☆'("☀ ☆ ☂"), Y = '☆'(Z), X=Y.

It is even possible to define operators:

:- op(100,xfy,'☆').

r(Z,M) :- X = '☀' '☆' '☂', Y = '☆'(Z,M), X=Y.

There are some limitations. First, unquoted characters cannot be used
neither as part of atoms nor variables names. Secnod, there is no
support for Unicode manipulation (unicode strings are represented as
code of 1-byte characters). You may translate the sequence of bytes in
UTF-8 to UTF-32. Ciao does not provide any functionality to do that,
but we may add it if there is interest.

However, if you only need to read and write back Unicode strings
without any manipulation, there should not be many problems.

Bests,