A roundup of what current interpreters do with k:
Syntax: first bit = k executes the instruction at k, not at the instruction
second bit = k skips over the instruction after executing
third bit = 0k doesn't execute the instruction
fourth bit = all iterations are executed at k
So here I think "1111" means what the spec says.
- !Befunge: 1000 (second bit cancels out fourth so nested k works)
- CCBI: 1110
- JQBF: 0110 (but 2k# jumps once from k?)
- PyFunge beta: 0111
- PyFunge CVS: 0110
- RC/Funge: 1010 (second bit cancels out fourth so nested k works)
The test code I used to figure out the fourth bit, using nested k:
v >"DAB",,, v
> 7654321 3213kk$7wv v>" ",.......a,@
>"DAB",,, ^
" > "DAB YREV",,,,,,,,a,@
>"DOOG",,,, ^