Editing Factor (programming language) (section)

==Implementation and libraries==
Factor includes a large standard library, written entirely in the language. These include
* A cross-platform GUI toolkit, built on top of [[OpenGL]] and various windowing systems, used for the development environment.<ref>{{cite web | url = http://docs.factorcode.org/content/article-ui.html | title = Factor documentation: UI framework | first = Slava | last = Pestov}}</ref>
* Bindings to several database libraries, including [[PostgreSQL]] and [[SQLite]].<ref>{{cite web | url = http://docs.factorcode.org/content/article-db.html | title = Factor documentation: Database library | first = Doug | last = Coleman}}</ref>
* An [[HTTP]] server and client, with the Furnace web framework.<ref>{{cite web | url = http://docs.factorcode.org/content/article-http.server.html | title = Factor documentation: HTTP server | first = Slava | last = Pestov}}</ref>
* Efficient homogeneous arrays of integers, floats and C structs.<ref>{{cite web | url = http://docs.factorcode.org/content/article-specialized-arrays.html | title = Factor documentation: Specialized arrays | first = Slava | last = Pestov}}</ref>
* A library implementing regular expressions, generating machine code to do the matching.<ref>{{cite web | url = http://docs.factorcode.org/content/article-regexp.html | title = Factor documentation: Regular expressions | first1 = Doug | last1 = Coleman | first2 = Daniel | last2 = Ehrenberg}}</ref>

A [[foreign function interface]] is built into Factor, allowing for communication with [[C (programming language)|C]], [[Objective-C]] and [[Fortran]] programs. There is also support for executing and communicating with shaders written in [[GLSL]].<ref name="dls"/><ref>{{cite web | first = Slava | last = Pestov | url = http://factor-language.blogspot.com/2010/07/overhauling-factors-c-library-interface.html | title = Overhauling Factor's C library interface| date = 28 July 2010 }}</ref>

Factor is implemented in Factor and [[C++]]. It was originally bootstrapped from an earlier Java implementation. Today, the parser and the optimizing compiler are written in the language. Certain basic parts of the language are implemented in C++ such as the garbage collector and certain primitives.

Factor uses an [[system image|image]]-based model, analogous to many [[Smalltalk]] implementations, where compiled code and data are stored in an image.<ref>{{cite web | first = Slava | last = Pestov | url = http://factor-language.blogspot.com/2010/01/factors-bootstrap-process-explained.html | title = Factor's bootstrap process explained| date = 10 January 2010 }}</ref>  To compile a program, the program is loaded into an image and the image is saved. A special tool assists in the process of creating a minimal image to run a particular program, packaging the result into something that can be deployed as a standalone application.<ref name="dls"/><ref>{{cite web | first = Slava | last = Pestov | url = http://factor-language.blogspot.com/2008/07/on-shaking-trees.html | title = On shaking trees| date = 5 July 2008 }}</ref>

The Factor compiler implements many advanced optimizations and has been used as a target for research in new optimization techniques.<ref name="dls"/><ref>{{cite web|first=Daniel |last=Ehrenberg |title=Closure elimination as constant propagation |url=http://factorcode.org/littledan/abstract.pdf |year=2010 |url-status=dead |archive-url=https://web.archive.org/web/20110726044425/http://factorcode.org/littledan/abstract.pdf |archive-date=2011-07-26 }}</ref>