________________________________________________________________________

This file is part of Logtalk <https://logtalk.org/>  
Copyright 1998-2021 Paulo Moura <pmoura@logtalk.org>  
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
________________________________________________________________________


Overview
========

This folder contains libraries of useful objects, categories, and protocols.
Specific notes about individual libraries can be found in the corresponding
library directory `NOTES.md` files.

A plain Prolog version of the Unicode 6.2 standard is also included in the
`unicode_data` folder. See its `README.md` file for details.

A `parallel_logtalk_processes_setup.pl` Prolog file is also provided with
sample code for selected backend Prolog compilers for initializing Logtalk
processes such that each process uses a unique scratch directory therefore
allowing parallel process execution (e.g. for usage at continuous integration
servers). See the comments in the file itself for usage instructions.


Library documentation
---------------------

Specific notes about each library can be found in the corresponding `NOTES.md`
files. HTML documentation for each library API can be found on the `docs`
directory (open the `../docs/index.html` file with your web browser). The
documentation for these libraries can be regenerated using the shell scripts
`../scripts/update_html_docs.sh` and `../scripts/update_svg_diagrams.sh`.


Loading libraries
-----------------

All the individual libraries can be loaded using the `<library name>(loader)`
notation as argument for the compiling and loading predicates. For example:

	| ?- logtalk_load(random(loader)).

For existing applications still relying on the old library `*_loader.lgt`
files, these loader files are still provided but are considered deprecated.

There is a file named `all_loader.lgt` that will load all libraries. Simply
type the goal:

	| ?- logtalk_load(library(all_loader)).

As a general rule, always use the corresponding loader file to load a
library. Most library entities are part of small hierarchies or depend on
other libraries and thus cannot be loaded and compiled separately (e.g. the
`list` object implements the `listp` protocol and is part of a basic types
hierarchy). Using the loader files takes care of all dependencies and also
ensures compilation in optimized mode.


Testing libraries
-----------------

Most of the libraries include unit tests in their directory, together with
a `tester.lgt` file for running them. For example, to run the tests for the
`random` library, we can use the goal:

	| ?- logtalk_load(random(tester)).

To run all libraries tests, we can use the `logtalk_tester` automation script
from the `library` directory at the root of the Logtalk distribution. For
example, assuming the Logtalk user directory is `~/logtalk` and that we want
to run the tests using ECLiPSe as the backend Prolog compiler:

	$ cd ~/logtalk/library
	$ logtalk_tester -p eclipse


Credits
-------

Some code in this library is based on public domain Prolog code, in particular,
code adopted from the Edinburgh Prolog library. The definition  of predicate
`reverse/2` in object list is from Richard O'Keefe and can be found in its book
"The Craft of Prolog".

Some elements of this library are inspired by Richard O'Keefe library proposal
available at:

http://www.cs.otago.ac.nz/staffpriv/ok/pllib.htm

Some libraries, or part of libraries, are either ports of Prolog system
libraries or inspired by Prolog system libraries. See the individual library
notes for details. See also the `NOTICE.txt` file at the root of the Logtalk
distribution for copyright information on third-party source code.


Other notes
-----------

Some files contained in this directory represent work in progress and are
not loaded by default by any loader utility file.
