View source for Red (programming language)

{{short description|Computer programming language released in 2011}}
{{Infobox programming language
| name = Red
| logo = Red Language Tower Logo.png
| logo caption =
| paradigm = [[Imperative programming|imperative]], [[Functional programming|functional]], [[Symbolic programming|symbolic]]
| designer = Nenad Rakočević<ref>{{cite web |title=Creator of Red |website=[[GitHub]] |url=https://github.com/dockimbel}}</ref>
| developer = Nenad Rakočević
| latest release date = December 7, 2018
| typing =
| implementations =
| dialects =
| influenced =
| license = modified BSD and Boost
| website = {{Official URL}}
| logo_size = 150px
| logo_alt = Red Logo (stylized Tower of Hanoi)
| year = 2011
| latest_release_version = 0.6.4<ref name=GC/> (Alpha)
| influenced_by = [[Rebol]], [[Scala (programming language)|Scala]], [[Lua (programming language)|Lua]]
| operating_system = [[Software:Linux|Linux]], [[Software:Windows|Windows]], [[Software:OS X|OS X]], Syllable
| file_ext = .red, .reds
}}
'''Red''' is a [[Programming language|programming language]] designed to overcome the limitations of the programming language [[Rebol]].<ref name="GS">{{cite web |title=Getting Started with GUI Programming using Red Language |url=https://www.studytonight.com/post/getting-started-with-gui-programming-using-red-programming-language |website=Studytonight |access-date=September 17, 2021}}</ref> Red was introduced in 2011 by Nenad Rakočević,{{Sfn|Balbaert|2018}} and is both an [[Imperative programming|imperative]] and [[Functional programming|functional programming]] language. Its syntax and general usage overlaps that of the interpreted Rebol language.<ref>{{cite web |title=Interview with Nenad Rakocevic about Red, a Rebol inspired programming language |url=https://www.notamonadtutorial.com/interview-with-nenad-rakocevic-about-red-a-rebol-inspired-programming-language/  |website=Not a Monad Tutorial|date=28 August 2015 | access-date=August 28, 2015}}</ref>

The implementation choices of Red intend to create a [[Solution stack|full stack]] programming language:{{Sfn|Balbaert|2018}}<ref name="MUO">{{cite web |title=6 Unusual & Groundbreaking Programming Languages to Learn in 2023|url=https://www.makeuseof.com/programming-languages-to-learn-in-2023/ |website=makeuseof.com |date=18 October 2023}}</ref> Red can be used for extremely high-level programming ([[Domain-specific language|DSL]]s and [[Graphical user interface|GUI]]s) as well as low-level programming ([[Operating system|operating system]]s and [[Device driver|device driver]]s). Key to the approach is that the language has two parts: ''Red/System'' and ''Red''.<ref name="developpez">{{cite news |last1=Lucas |first1=Mathis |title=Red: an imperative and functional programming language that is also a "full battery" language|url=https://programmation.developpez.com/actu/346670/Red-un-langage-de-programmation-imperatif-et-fonctionnel-et-decrit-comme-un-langage-a-pile-complete-c-est-a-dire-qu-il-peut-etre-utilise-pour-la-programmation-de-haut-niveau-et-de-bas-niveau/ |newspaper=Developpez.com |date=21 July 2023 |access-date=16 January 2023}}</ref>

* ''Red/System'' is similar to C, but packaged into a Rebol lexical structure{{snd}} for example, one would write {{Smalltalk|if x > y [print "Hello"]}} instead of {{C-lang|if (x > y) {printf("Hello\n");} }}.
* ''Red'' is a [[Homoiconicity|homoiconic language]]<ref name="GS">{{cite web |title=Getting Started with GUI Programming using Red Language |url=https://www.studytonight.com/post/getting-started-with-gui-programming-using-red-programming-language |website=Studytonight |access-date=September 17, 2021}}</ref> capable of meta-programming, with Rebol-like semantics. Red's runtime library is written in Red/System, and uses a hybrid approach: it [[Compiled language|compiles]] what it can deduce statically and uses an embedded [[Interpreter (computing)|interpreter]] otherwise. The project roadmap includes a [[Just-in-time compilation|just-in-time compiler]] for cases in between, but this has not yet been implemented.

Red seeks to remain independent of any other toolchain; it does its own code generation.<ref name="GS">{{cite web |title=Getting Started with GUI Programming using Red Language |url=https://www.studytonight.com/post/getting-started-with-gui-programming-using-red-programming-language |website=Studytonight |access-date=September 17, 2021}}</ref> It is therefore possible to [[Cross compiler|cross-compile]]<ref name="MUO">{{cite web |title=6 Unusual & Groundbreaking Programming Languages to Learn in 2023|url=https://www.makeuseof.com/programming-languages-to-learn-in-2023/ |website=makeuseof.com |date=18 October 2023}}</ref> Red programs from any platform it supports to any other, via a command-line switch. Both Red and Red/System are distributed as [[Open-source software|open-source software]] under the modified BSD license. The runtime library is distributed under the more permissive Boost Software License.

As of version 0.6.4 Red includes a [[Garbage collection (computer science)|garbage collector]] "the Simple GC".<ref name=GC>{{Cite web|url=https://www.red-lang.org/2018/12/064-simple-gc-and-pure-red-gui-console.html|title=0.6.4 Simple GC and Pure Red GUI Console|quote=The main feature for 0.6.4 is what we call the Simple GC (Garbage Collector). A more advanced GC is planned for the future |last=lucindamichele|access-date=2018-12-16}}</ref>

[[File:Red architecture small.PNG|thumb|306px|Red Language architecture schema]]

==Introduction==
Red was introduced in the Netherlands in February 2011 at the ''Rebol & Boron conference''<ref>[http://www.osnews.com/story/24798/New_Red_Programming_Language_Gets_Syllable_Backend « New Red Programming Language Gets Syllable Backend »], ''osnews.com'', May 2011.</ref> by its author Nenad Rakočević. In September 2011, the Red programming language was presented to a larger audience during the [[Software Freedom Day]] 2011.<ref name="Red SFD 2011">[https://www.red-lang.org/2011/09/red-at-software-freedom-day-2011.html « Red Programming Language: Red at Software Freedom Day 2011 »], ''red-lang.org'', September 14, 2011.</ref><ref name="YT SFD 2011">{{cite web |title=Software Freedom Day 2011: Red programming language, a new REBOL dialect|url=https://www.youtube.com/watch?v=wgtgoliZ454 |website=YouTube |access-date=17 January 2023}}</ref> Rakočević is a long-time Rebol developer known as the creator of the Cheyenne [[HTTP server]].<ref>[http://cheyenne-server.org/about.shtml « What is Cheyenne? »] Last referenced Nov 2017.</ref>

==Features==
Red's syntax and semantics are very close to those of [[Rebol]].{{Sfn|Balbaert|2018}}<ref>{{cite web |title=The Dynamic Mapping Architecture |url=https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=toledo1639760375713532&disposition=inline |website=OhioLINK |date=December 2021}}</ref> Like Rebol, it strongly supports [[Metaprogramming|metaprogramming]] and domain-specific languages ([[Domain-specific language|DSLs]]) and is therefore a highly efficient tool for dialecting (creating embedded DSLs). Red includes a dialect called Red/System, a C-level language which provides system programming facilities.<ref name="developpez"></ref> Red is easy to integrate with other tools and languages as a DLL (libRed) and very lightweight (around 1&nbsp;MB). It is also able to cross-compile to various platforms (see Cross Compilation section below) and create packages for platforms that require them (e.g., .APK on Android).<ref name="developpez"></ref> Red also includes a fully reactive cross-platform GUI system based on an underlying reactive dataflow engine, a 2D drawing dialect comparable to SVG, compile-time and runtime macro support, and more than 40 standard datatypes.

==Goals==
The following is the list of Red's Goals as presented on the [[Software Freedom Day]] 2011:<ref name="Red SFD 2011"></ref><ref name="YT SFD 2011"></ref>

* Simplicity ("An IDE should not be necessary to write code.")
* Compactness ("Being highly expressive maximizes productivity.")
* Speed ("If too slow, it cannot be general-purpose enough.")
* Be "Green", Have a Small Footprint ("Because resources are not limitless.")
* Ubiquity ("Spread everywhere.")
* Portability, Write once run everywhere ("That's the least expected from a programming language.")
* Flexibility ("Not best but good fit for any task!")

==Development==
Red's development is planned to be done in two phases:

# Initial phase: Red and Red/System compilers written in [[Rebol]] 2
# [[Bootstrapping (compilers)|Bootstrap]] phase: Red and Red/System compilers complemented by a Red JIT-compiler, all written in Red

==Cross compilation==
Red currently supports the following cross-compilation targets:

* [[Software:MS-DOS|MS-DOS]]: Windows, [[X86|x86]], console (and GUI) applications
* [[Software:Microsoft Windows|Windows]]: Windows, x86, GUI applications
* [[Software:Linux|Linux]]: [[Software:Linux|Linux]], x86
* Linux-ARM: [[Software:Linux|Linux]], [[ARM architecture|ARMv5]], [[ARM architecture|armel]] (soft-float)
* [[Engineering:Raspberry Pi|Raspberry Pi]]: [[Software:Linux|Linux]], [[ARM architecture|ARMv5]], armhf (hard-float)
* [[Software:FreeBSD|FreeBSD]]: [[X86|x86]]
* [[Software:Darwin (operating system)|Darwin]]: [[Software:OS X|OS X]] Intel, console (and GUI) applications
* [[Software:Syllable Desktop|Syllable]]: [[Software:Syllable Desktop|Syllable OS]], [[X86|x86]]
* [[Software:Android (operating system)|Android]]: Android, [[ARM architecture|ARMv5]]
* Android-x86: Android, [[X86|x86]]
<small>(Note: This list will increase with time and should therefore be considered as incomplete.)</small>

==Hello World!==
<source lang="red">
Red [Title: "Simple hello world script"]
print "Hello World!"
</source>

==Factorial example==
IMPORTANT: These are intended as syntax examples. Until Red has [[64-bit computing|64-bit]] support, the integer example will overflow a [[32-bit|32-bit]] integer very quickly. Changing that to `float!` will go farther, but these are merely to show the syntax of the language.

The following is a factorial example in Red:

<source lang="red">
Red [Title: "A factorial script"]  ; Note: The title is optional.

factorial: func [
	x [integer!]  ; Giving the type of an argument in Red is optional
][
	either x = 0 [1][x * factorial x - 1]
]
</source>

The following is the same factorial example in Red/System (in this very simple case, the source code is very similar to Red's version):

<source lang="red">
Red/System [Title: "A factorial script"]

factorial: func [
	x       [integer!]                   ; This is compulsory in Red/System
	return: [integer!]                   ; This is compulsory in Red/System
][
	either x = 0 [1][x * factorial x - 1]
]
</source>

==See also==
* [[Rebol]]

==References==
{{Reflist}}

== Further reading ==
* {{Cite book |last1=Balbaert |first1=Ivo  |date=May 2018 |title=Learn Red - Fundamentals of Red|publisher=Packt Publishing|isbn=978-1789130706 |language=en}}

==External links==
* [https://red.github.io/ Red Programming Language] on [[GitHub]]
* [https://redprogramming.com/ Redprogramming.com]
* {{GitHub|red/red}}

{{Programming languages}}

[[Category:Programming languages]]
[[Category:Systems programming languages]]
[[Category:Extensible syntax programming languages]]
[[Category:Domain-specific programming languages]]
[[Category:High-level programming languages]]
[[Category:Homoiconic programming languages]]
[[Category:Procedural programming languages]]
[[Category:Functional languages]]
[[Category:Cross-platform free software]]
[[Category:Cross-platform software]]
[[Category:Free compilers and interpreters]]
[[Category:Software using the BSD license]]

{{Sourceattribution|Red (programming language)}}