BlooP - Esoteric programming language

BlooP is an esoteric programming language created in 1979.

#1049on PLDB

45Years Old

BlooP and FlooP are simple programming languages designed by Douglas Hofstadter to illustrate a point in his book Gödel, Escher, Bach. BlooP is a non-Turing-complete programming language whose main control flow structure is a bounded loop (i.e. recursion is not permitted). Read more on Wikipedia...

Tags: esoteric programming language
Early development of BlooP happened in Fluid Analogies Research Group
Explore BlooP snippets on Rosetta Code
BlooP on HOPL

Example from hello-world:

DEFINE PROCEDURE ''HELLO-WORLD'' [N]:
BLOCK 0: BEGIN
     PRINT['Hello World']
BLOCK 0: END.
HELLO-WORLD[1];

Example from Wikipedia:

DEFINE PROCEDURE ''ACKERMANN'' [M, N]:
BLOCK 0: BEGIN
	CELL(0) ⇐ M;
	OUTPUT ⇐ N;
	CELL(1) ⇐ 0;
	MU-LOOP:
	BLOCK 1: BEGIN
		IF CELL(0) = 0, THEN:
		BLOCK 2: BEGIN
			OUTPUT ⇐ OUTPUT + 1;
			IF CELL(1) = 0, THEN: ABORT LOOP 1;
			CELL(0) ⇐ TOP [CELL(1)];
			CELL(1) ⇐ POP [CELL(1)];
			QUIT BLOCK 1;
		BLOCK 2: END
		IF OUTPUT = 0, THEN:
		BLOCK 3: BEGIN
			OUTPUT ⇐ 1;
			CELL(0) ⇐ MINUS [CELL(0), 1];
			QUIT BLOCK 1;
		BLOCK 3: END
		OUTPUT ⇐ MINUS [OUTPUT, 1];
		CELL(1) ⇐ PUSH [MINUS [CELL(0), 1], CELL(1)];
	BLOCK 1: END;
BLOCK 0: END.

Language features

Feature	Supported	Example	Token
Strings	✓	'Hello world'	'
Print() Debugging	✓		PRINT