Commlang

Commlang was an attempt by User:Monochromeninja to create a community-based esolang, but ended up doing it their own way.

Commlang uses a single stack of integers. EOF is -1, empty stack is repeated 0, and stack indices are 0-based, where negative indices start at the bottom.

Commands

Commlang has the following commands. Either the shorthand or verbose form may be used for each command.

Shorthand command	Verbose command	Description
{N}	push N	Push N to the stack.
!	pop	Pop the top of the stack.
`	del	Pop X, then delete the X'th item of the stack. (! and {0}` are equivalent)
:	dup	Duplicate the top of stack.
_	in	Push a single character of input, converted to its codepoint.
"	out	Pop X, interpret it as a codepoint, then output it.
+	add	Pop A, pop B, push B + A.
-	sub	Pop A, pop B, push B - A.
*	mul	Pop A, pop B, push B * A.
/	div	Pop A, pop B, push B / A rounded down.
%	mod	Pop A, pop B, push B % A.
~	neg	Pop X, push -X.
=	eq	Pop A, pop B, push 1 if B == A, else 0.
<	less	Pop A, pop B, push 1 if B < A, else 0.
@	swap	Swap the top two elements of the stack.
[F]	[F]	Push function F to the stack.
^	call	Pop function F and insert its code immediately after the ^.
.	comp	Pop function F, pop function G, push the function that consists of G's code concatenated with F's code.
$	pick	Pop X, then copy the X'th item of the stack to the top. (: and {0}$ are equivalent)
?	rand	Pop X, then push a random integer between 0 and X inclusive.
#	debug	Toggle debug info. (interpreter-specific)

Examples

Cat program:

[:{2}${1}~=[{2}$_{2}`@!@:^]@[]@`^]:^!!![:{2}${0}=[{1}~$"{1}~`^]@[]@`^]:^

In verbose form:

[
 dup
 push 2 pick
 push 1 neg eq
 [
  push 2 pick
  input
  push 2 del
  swap pop swap
  dup call
 ]
 swap
 []
 swap
 del call
]
dup call
pop pop pop
[
 dup
 push 2 pick
 push 0 eq
 [
 push 1 neg
 pick out
 push 1 neg del
 call
 ]
 swap
 []
 swap
 del call
]
dup call

Infinite loop:

[:^]:^

In verbose form:

[
 dup call
]
dup call

External resources

• Reference interpreter