Cupid

Cupid is a brainfuck derivative.

There are nine commands which are processed in two-character sequences. The command sequences are formed by using characters '<', '>', and '-'. Only difference, or rather, addition to brainfuck is that in Cupid it's possible to output the current state of the storage tape.

Commands

>>  input a byte to current cell
<<  output the current cell as character
->  move memory pointer one right
<-  move memory pointer one left
><  increase the current cell
<>  decrease the current cell
-<  if the current cell is zero, jump to the corresponding >-, otherwise continue
>-  jump back to the corresponding -<
--  output the current state of the storage tape

Interpreter

#!/usr/bin/env ruby
eval 'm=Hash.new(p=0);'+ARGF.read.gsub(
       /[-><][-><]|./,
       '->' => 'p+=1;',
       '<-' => 'p-=1;',
       '><' => 'm[p]+=1;',
       '<>' => 'm[p]-=1;',
       '<<' => 'putc m[p];',
       '>>' => 'm[p]=STDIN.getbyte if !STDIN.eof;',
       '-<' => '(',
       '>-' => ')while((m[p]&=255)!=0);',
       '--' => 'print p,",",m,"\n";')

External resources

• Shane Torbert's Cupid page (from the Wayback Machine; retrieved on 30 August 2006), featuring an interpreter