lol... thats what you think... you should see an IF structure in BrainF*ck !

lets say you want to compare memory address 0 to memory address 1 and if they are equal DO somthing, (Without destroying the variables, you must....

1) make a copy of the varibales to work on in memory at address 2 and 3. (so noot to change origonal variables)
to make a copy of memory address 0 to memory address 2 you need to loop through subtracting one from address zero, adding one to memory address 2 and 5(temp) on each loop... then loop through address 5 subtracting one, and addinng one to address 0 on each loop.

all of that just to make a copy of a varrable.. and you have to do that twice....

here is the brainf*ck code to copy a variable


2)NEXT... you need to determine if the coppied variables are equal.
loop through coppied variable one subtracing one on each loop from itself, and coppyied variable 2.
if the variables are equal, then the body of a while next loop will not be entered from the address of coppied variable 2.....

code for "If A is not equal to B"


to make a "If A is equal to B" test, you would need to set anouther variable to one, and then enter it with a while loop... but if the NOT EQUAL code is executed, it sets the one variable to zero, preventing the while loop from being entered....

like so...




SO.......
In assembly, an if statement is as simple as a jump instruction, with a condition, and an address...
in BrainFu*k an if code looks like this.......

My Example of a rainF8CK IF THEN ELSE statement


and ontop of that, you have to make sure the code you insert into the TRUE and FALSE doesn not interfere with any ariables the IF THEN ELSE code uses.

i havent debuged that, its just off the top of my head, so dont be surprised if it doesnt work


Ohhh, and iif you think that looked complicated, you dont even want to know what an "IF A is bigger than B" looks like !!!!

Someone pointed out that that's actually "move pointer 3; add 2; while (not zero) {". But understanding the semantics of the language is just the first step. If anyone wants to actually understand how the program works, the first step is to read my explanation at http://www.hevanet.com/cristofd/bf/random.txt which assumes some familiarity with the language and with cellular automata too; and the second step is to ask me questions, if it still isn't clear (and you're still interested).
Good luck;
-Daniel Cristofani.

Not entirely necessary. Here's another approach:



-Daniel.

your code makes no sence to me....



this executes straigth after a closed loop... the the contents of the memory will alsways equal zero, so this loop is never entered.. and if it was entered, it would just loop round subtracting one untill it was at zero...

Exactly. That part is a comment. The actual working code is these three lines:



and then to explain what it was doing I added comments which are a map of the memory, so for instance when I wrote



I meant that after this line of code is done executing, the first cell has (A minus B), the second cell has a zero, the third cell has B, and the fourth and fifth cells have zeroes.

Then, to prevent the "-" in the comments from being executed as a brain**** command, I put the comments in loops that would never be executed, because the cell was known to be zero. Maybe I should have explained that to begin with?

-Daniel.

Ahhh.. okay i understand...
for simplicity, i just make sure not to use BF code in comments..

i use SUB for '-' and ADD for '+'.

great language though !

makes me want to attempt to learn assembly.... again !

This language is very complicated considering the minimal amount of commands. I greatly admire anyone who takes the time to use it on complex programs. Even simple programs for that matter. Are there many games written in it? Does anyone know where i try some out?

No games yet. Probably the closest thing is the cellular automaton "life", here:
http://www.df.lth.se/~lft/brain****/

Tic-tac-toe and guess-a-number are on my to-do list, but they've been there a while.

The best general source for brain**** source code is the repository at:
http://esoteric.sange.fi/brain****/

(Fix censoring in both URLs.)

Good luck;
-Daniel Cristofani.

Here is my version of a BrainF*ck compiler for DOS, 114 byte sized:



For those who don't want to assemble this compiler of BF, here is the uuencoded version of the COM executable:




You use this compiler to generate .COM executables from BF source code. The source code must not have any character other than BF commands, and the BF program must end with the "@" character flag. For example, the random number generator above mentioned:



Then you use the compiler by writing this command line:

BF <RANDOM.BF >RANDOM.COM

And then you run RANDOM.COM to watch the result...

If you need to clean up the code, you can use my BF sourcecode cleaner (CLEAN.BF):



Then you compile CLEAN.BF into CLEAN.com:

BF <CLEAN.BF >CLEAN.COM

And then, to compile any commented BF program:

CLEAN <program.bf | BF >program.com

Try out this code:



This is my Hello World in BF:



I've attached a BF debugger of my creation for debugging these BF programs (so you will understand quickly their operation.