Write code in the textarea (all whitespace is ignored). Add new input registers, run the program, and format the code (beautify) with buttons above.

Output registers (if not empty) are printed in the "Output" section after running the program.

Errors are printed in the "Errors" section after running/formatting the program. Errors include parsing errors (incorrect syntax) and runtime errors (for example jumping to a non-existing label).

Seven instructions are supported:

1. addj RX - adds j to the right end of the string in RX
2. del RX - deletes the first from left symbol of the string stored in RX
3. clr RX - clears the string in RX
4. RX <- RY - copies the string in RY into RX
5. jmp N1 - jumps to the instruction with line label N1
6. RX jmpj N1 - jumps to the instruction with line label N1 if the first symbol of the string in RX is j
7. continue - ends execution

Each instruction can be prefixed with a line label, for example N1: add0 RX