Suzy

Suzy is a 3D esoteric programming language, inspired by Befunge, superseding 3D. Suzy source is compiled to byte-code in the original implementation. Comments are made by directing code flow around them. It includes file I/O as well as STDIN/STDOUT. Every non-control ASCII character is used as an operation or variable name.

Commands

No-op:
	  (space) do nothing
	| vertical pipe (do nothing)
	- horizontal pipe (if not in math mode)
	' lateral pipe
Execution control:
	@ end
Flow control:
	{ right
	} left
	^ up
	_ down
	[ forwards
	] backwards
	% random direction
	# jump
	$ conditional jump
Conditional jump preparation:
	= equality
	< smaller than
	> greater than
Input/output:
	? input
	! output
File access:
	/ open a file for input and output
Libraries:
	+ load a library
Variable handling:
	: set a variable to a value
	( enter math mode
	) leave math mode
	" enter/leave unicode mode
	. cat strings
	, substring
	~ swap two variables
String mode:
	` temporary escape unicode mode, for changing directions
	\ escape sequence
Math mode:
	+ addition
	- subtraction
	* multiplication
	/ division
	% modulus division
Numeric:
	0-9 numeric constants
Variable names:
	A-Z string variable names
	a-z integer variable names
	\ indirect variable mode (if not in ascii/unicode mode)
Arguments:
	; separates 2 arguments
Unused:
	& unused in Suzy proper (except in strings, of course), but can be used in a Suzy source file to separate sheets

Example

The following lists all primes up to a given bound:

32,7,3
}!"Primes up to: "?A ~Aa       ]
 a is the maxprime
 p is the index of the stack
 stack is the list of primes
 n is the number that is
      checked for primeness
 i is a temp stack index
&
 ] 3n:1p: "2"! _$0001a>   2;0\:{
               }!"Too large!\n"@
&
 } >na$@ --- :i0 } =(n/\i*\i)n _
 |               ^---------{   $
 |                 }:i(i+1)^   #
 |  _p:p\!np\:" ,"!^$)n/(i\<   {
 |  }(p+1)  _                  |
 ^--)1+n(n: {------------------{

Computational class

The author thinks Suzy is Turing Complete, because it is possible to translate any BrainFuck program to Suzy:

> becomes :p(p+)
< becomes :p(p-)
+ becomes :\p(\p+)
- becomes :\p(\p-)
[ becomes }=\p0$_ (with a pipe from _ to the corresponding })
] becomes _} (with a pipe from _ to the corresponding })

Input and output work differently, but could be translated as:

, becomes ?\p
. becomes !\p

However, I/O is not necessary for Turing Completeness, so that doesn't matter.

Implementation

A full featured implementation in Python of both byte-code compiler and interpreter are on GitHub.