Refal

Refal is a programming language created in 1968 by Valentin Turchin.

#910on PLDB

56Years Old

Refal (Recursive functions algorithmic language) "is functional programming language oriented toward symbol manipulation", including "string processing, translation, [and] artificial intelligence". It is one of the oldest members of this family, first conceived in 1966 as a theoretical tool with the first implementation appearing in 1968. Refal was intended to combine mathematical simplicity with practicality for writing large and sophisticated programs. Read more on Wikipedia...

Refal website
Refal Wikipedia page
Refal first developed in http://pespmc1.vub.ac.be/TURCHIN.html
Explore Refal snippets on Rosetta Code
Refal on HOPL
refal.net was registered in 1999
See also: (2 related languages)Prolog, Lisp

Example from hello-world:

$ENTRY Go { = <Hello>;}
Hello {
   = <Prout 'Hello World'>;
}

Example from the Hello World Collection:

* Hello world in Refal

$ENTRY Go { = <Hello>;}
Hello {
   = <Prout 'Hello world'>;
}

Example from Wikipedia:

Squeeze {
    '__'e.1 = <Squeeze '_'e.1>;
    s.A e.1 = s.A <Squeeze e.1>;
    = ; };

Feature	Supported	Token	Example
Strings	✓	'	'Hello world'
Print() Debugging	✓
Comments	✓		* A comment
Line Comments	✓	*	* A comment
Semantic Indentation	X

Language features