Examples
var brainfuck = ; ; // [5]brainfucktext'+++++++++[>++++++++++>++++++++++++>++++<<<-]>-.>+++.>---.' // 'Yo!'
Language design
Source: Wikipedia
Urban Müller created brainfuck in 1993 with the intention of designing a language which could be implemented with the smallest possible compiler, inspired by the 1024-byte compiler for the FALSE programming language.
Commands
Source: Wikipedia
Character | Meaning |
---|---|
> |
increment the data pointer (to point to the next cell to the right). |
< |
decrement the data pointer (to point to the next cell to the left). |
+ |
increment (increase by one) the byte at the data pointer. |
- |
decrement (decrease by one) the byte at the data pointer. |
. |
output the byte at the data pointer. |
, |
accept one byte of input, storing its value in the byte at the data pointer. |
[ |
if the byte at the data pointer is zero, then instead of moving the instruction pointer forward to the next command, jump it forward to the command after the matching ] command. |
] |
if the byte at the data pointer is nonzero, then instead of moving the instruction pointer forward to the next command, jump it back to the command after the matching [ command. |
ROT13
Source: Wikipedia
brainfucktext'-,+[-[>>++++[>++++++++<-]<+<-[>+>+>-[>>>]<[[>+<-]>>+>]<<<<<-]]>>>[-]+>--[-[<->+++[-]]]<[++++++++++++<[>-[>+>>]>[+[<+>-]>+>>]<<<<<-]>>[<+>-]>[-[-<<[-]>>]<<[<<->>-]>>]<<[<<+>>-]]<[-]<.[-]<-,+]' 'abc'; // 'nop'
-,+[ Read first character and start outer character reading loop -[ Skip forward if character is 0 >>++++[>++++++++<-] Set up divisor (32) for division loop (MEMORY LAYOUT: dividend copy remainder divisor quotient zero zero) <+<-[ Set up dividend (x minus 1) and enter division loop >+>+>-[>>>] Increase copy and remainder / reduce divisor / Normal case: skip forward <[[>+<-]>>+>] Special case: move remainder back to divisor and increase quotient <<<<<- Decrement dividend ] End division loop ]>>>[-]+ End skip loop; zero former divisor and reuse space for a flag >--[-[<->+++[-]]]<[ Zero that flag unless quotient was 2 or 3; zero quotient; check flag ++++++++++++<[ If flag then set up divisor (13) for second division loop (MEMORY LAYOUT: zero copy dividend divisor remainder quotient zero zero) >-[>+>>] Reduce divisor; Normal case: increase remainder >[+[<+>-]>+>>] Special case: increase remainder / move it back to divisor / increase quotient <<<<<- Decrease dividend ] End division loop >>[<+>-] Add remainder back to divisor to get a useful 13 >[ Skip forward if quotient was 0 -[ Decrement quotient and skip forward if quotient was 1 -<<[-]>> Zero quotient and divisor if quotient was 2 ]<<[<<->>-]>> Zero divisor and subtract 13 from copy if quotient was 1 ]<<[<<+>>-] Zero divisor and add 13 to copy if quotient was 0 ] End outer skip loop (jump to here if ((character minus 1)/32) was not 2 or 3) <[-] Clear remainder from first division if second division was skipped <.[-] Output ROT13ed character from copy and clear it <-,+ Read next character] End character reading loop