Language Reference

All of Subterra's instructions are documented here.

Command	Effect	Version Added
~	Turns everything after it until the end of a line into a comment.
0-9	Pushes an integer to the stack. (Note that 15 will push [15], not [1,5])
+-*/%	Pops two integers off the stack and pushes the result of the corresponding math operation (using -, [6,2] -> [4]).
r	Pops an integer from the stack and pushes a random number between 0 (inclusive) and that number (exclusive).	v1.1
$	Pops the top of the stack and deletes it.
&	Duplicates the top of the stack.
b	Moves the top of the stack to the bottom.
t	Moves the bottom of the stack to the top.
@	Reverses the entire stack.
s	Pushes the size of the stack ([3,2,1] -> [3,2,1,3]).
e	Empties the stack.
=	Pops two elements and pushes whether they are equal.
!	Pops two elements and pushes whether they are not equal.
<	Pops two elements and pushes whether the lower is less than the upper.
>	Pops two elements and pushes whether the lower is greater than the upper.
?	Pops the top of the stack and executes the following subroutine if the resulting value is not 0.
:	Can only be used after a ?; executes the following subroutine if the value was 0.
w	Calls the following subroutine, then if it's return value is not 0 executes the second. Repeats until the first subroutine returns 0.
p	Pops the top of the stack and prints it as an integer.
c	Pops the top of the stack and prints it as a Unicode character.
i	Waits for user input, then pushes it as a string (see Non-Integer Datatypes).
"	Pushes everything between itself and the next " as a string (see Non-Integer Datatypes). Respects valid escape sequences prefixed with \ as standard ASCII characters.
'	The same as "; can be used to avoid incessant escaping.
\	Pushes the Unicode value of the following character to the stack rather than executing it.
{[(	Begins a subroutine definition (see Understanding Subroutines).
}])	Ends a subroutine definition (see Understanding Subroutines).
#	Pops the top of the stack and calls the corresponding subroutine.
d	Pushes the program's current recursion depth. Useful for preventing code from running when a module is imported (can be used analagously to Python's if __name__ == '__main__' by checking it against 0).
m	Pops a string from the stack and imports the file at that path. See Import System for details.
.	Calls an imported subroutine using the next two integers (respectively import ID and subroutine ID). See Import System for details.
Space, Tab, Newline, `	;`	Token seperators (i.e. 15 will push [15], where 1;5 will push [1,5]). Will be otherwise ignored.