c1289aabe057394055e39b19ad26cee929604cac
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tmpod
1 year, 5 months ago
2b3b2e8

Add example programs

3 files changed,72insertions(+),0deletions(-) A examples/hello_world.bf A examples/hello_world_mini.bf A examples/rot13.bf

A examples/hello_world.bf => examples/hello_world.bf +43 -0

@@ 0,0 1,43 @@[ This program prints "Hello World!" and a newline to the screen, its length is 106 active command characters. [It is not the shortest.] This loop is an "initial comment loop", a simple way of adding a comment to a BF program such that you don't have to worry about any command characters. Any ".", ",", "+", "-", "<" and ">" characters are simply ignored, the "[" and "]" characters just have to be balanced. This loop and the commands it contains are ignored because the current cell defaults to a value of 0; the 0 value causes this loop to be skipped. ] ++++++++ Set Cell #0 to 8 [ >++++ Add 4 to Cell #1; this will always set Cell #1 to 4 [ as the cell will be cleared by the loop >++ Add 2 to Cell #2 >+++ Add 3 to Cell #3 >+++ Add 3 to Cell #4 >+ Add 1 to Cell #5 <<<<- Decrement the loop counter in Cell #1 ] Loop until Cell #1 is zero; number of iterations is 4 >+ Add 1 to Cell #2 >+ Add 1 to Cell #3 >- Subtract 1 from Cell #4 >>+ Add 1 to Cell #6 [<] Move back to the first zero cell you find; this will be Cell #1 which was cleared by the previous loop <- Decrement the loop Counter in Cell #0 ] Loop until Cell #0 is zero; number of iterations is 8 The result of this is: Cell no : 0 1 2 3 4 5 6 Contents: 0 0 72 104 88 32 8 Pointer : ^ >>. Cell #2 has value 72 which is 'H' >---. Subtract 3 from Cell #3 to get 101 which is 'e' +++++++..+++. Likewise for 'llo' from Cell #3 >>. Cell #5 is 32 for the space <-. Subtract 1 from Cell #4 for 87 to give a 'W' <. Cell #3 was set to 'o' from the end of 'Hello' +++.------.--------. Cell #3 for 'rl' and 'd' >>+. Add 1 to Cell #5 gives us an exclamation point >++. And finally a newline from Cell #6

A examples/hello_world_mini.bf => examples/hello_world_mini.bf +1 -0

@@ 0,0 1,1 @@++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.

A examples/rot13.bf => examples/rot13.bf +28 -0

@@ 0,0 1,28 @@-,+[ 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