BlooP

BlooP is an esoteric programming language created in 1979.

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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...

BlooP Wikipedia page
BlooP first developed 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.

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

BlooP - Esoteric programming language

Language features