.. _lua-functions:

###################
Lua Functions
###################

Lua Standard Libraries

The standard Lua libraries provide useful functions that are implemented
directly through the C-API. Some of these functions provide essential services 
to the language (e.g., :ref:`lua-func-type` and :ref:`lua-func-getmetatable`); 
others provide access to "outside" services (e.g., I/O); and others could be
implemented in Lua itself, but are quite useful or have critical performance
requirements that deserve an implementation in C (e.g., :ref:`lua-func-table.sort`).

All libraries are implemented through the official C API
and are provided as separate C modules.
Currently, Lua has the following standard libraries:

* basic library, which includes the coroutine sub-library;

* package library;

* string manipulation;

* table manipulation;

* mathematical functions (sin, log, etc.);

* input and output;

* operating system facilities;

* debug facilities.

Except for the basic and package libraries, each library provides all its
functions as fields of a global table or as methods of its objects.

.. toctree::
   :maxdepth: 1

   base.txt
   coroutine.txt
   debug.txt
   io.txt
   math.txt
   os.txt
   package.txt
   string.txt
   table.txt

Extensions

.. toctree::
   :maxdepth: 1

   inspect.txt
   jit.txt
   lua-utf8.txt
   lxr.txt
   struct.txt

:sub:`id-1780446`