=pod

Z<CHP-6>

=head1 PIR Standard Library

PIR and PASM are both very low-level languages by any programming
standards, even though they support some important features of
high-level dynamic languages,and PIR has some symbolic syntax features.
Important re-occurring programming tasks in these languages have been
extracted out into a series of runtime libraries to help make these
tasks easier. Libraries written in PIR or PASM can be easily included
and used from any of the high-level language compilers that target
Parrot, in addition to being used in the Parrot test suite and
PIR/PASM code generators like PCT.

Some modules, such as F<pcre.pir> and F<postgres.pir> are NCI wrappers
for common compiled shared libraries.

From the Parrot repository, there are a number of premade libraries in
F<runtime/library/>, and several generated libraries in F<runtime/include>
that can be used by Parrot hackers and HLL-implementers alike, if needed.
This chapter is going to give a brief overview of some of these libraries
and how they are used.

=head1 Loading and Using Libraries

Libraries are precompiled code files that can be loaded into Parrot. There
are ways to load a library into Parrot, each with a slightly different
mechanism. The C<.loadlib> PIR directive causes the library file to be loaded
at compile-time. The C<load_lib> opcode causes the library to be loaded
dynamically at runtime.

=head1 General Parrot Libraries

=head2 F<Config.fpmc>

C<Config.fpmc> is generated during the build process. The file defines a
hash PMC that contains information about the system where Parrot was
built. By accessing the data in this PMC, you can determine how Parrot
was compiled and what features and libraries it has available.

=head1 Perl-Inspired Libraries

Since the Parrot project started as the internals of the Perl 6 development
project, and since a number of Perl hackers are very active in Parrot,
several libraries in the Parrot runtime are based on common Perl 5 libraries.

=head2 F<Dumper.pir> and F<Data/Dumper.pir>

Perl 5 had C<Data::Dumper>, that would print out the complete contents and
structure of any arbitrary complex data type. This is useful in a number of
cases, with debugging not the least of them. It's good to verify that
complicated nested data structures are being composed and accessed in the
manner that the programmer intends.

=head1 NCI Wrapper Libraries

Parrot does not intend to reinvent any wheels, and there is lots of important
functionality encapsulated in various libraries that Parrot does not copy.
Instead of having to reimplement all sorts of libraries for Parrot, Parrot
provides the NCI interface to work with these libraries directly. PIR or
PASM wrapper libraries are provided to create an interface that programs
running on Parrot can use to access functionality in these libraries.

Notice that these libraries are depending on having the compiled libraries
they reference already installed on your system. Many of these are detected
during the configuration process. If you do not have these libraries
installed, you cannot call the modules discussed here. We will give some
information about how to find and install the libraries, however.

Notice that this is only a partial list of wrapper libraries that come
bundled with the Parrot repository. Additional library wrappers may be
added to the repository at a later date, or may be available from other
sources.

=head2 PCRE

PCRE is a library that implements regular expressions using Perl 5 syntax.


=head2 NCurses

NCurses is a library for manipulating the console and the cursor.

=head2 OpenGL

OpenGL is a 3D graphics library.

=head2 Postgres SQL

=head2 SDL

=head1 Mod_Parrot and CGI libraries

Parrot is also available, through a related but separate development effort
as a module for the Apache web server, Mod_Parrot. Mod_Parrot allows
Parrot and the high-level languages which target it to be used in Apache
to generate web content. Several libraries are available in the Parrot
repository that can help manage these requests.

=cut

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