BrainFlow
What is BrainFlow?
BrainFlow is an extension of BrainF**k (BFk) with 3 additional commands for added functionality and confusion.
What commands?
In addition to the normal BFk commands, we also have:
^ Jumps to the cell # depending on the value in the cell. Ex: If we are at cell # 0 with a value of 4, ^ will jump us to cell # 4.
= Sets the value at the cell to the index of the cell. Ex: If we are at cell # 4 with a value of 0, = will set our value to 4.
& Will set the value at the current cell equal to the value at the cell based on the value in our current cell. (This one's hard to word, so here's an example!) Ex: We are at cell # 33 and our current value at this cell is 7, & will set our current value at cell # 33 to whatever value is in cell # 7.
Optional Challenges
Accomplishing any of the following will apply the specified bonus to your byte count.
Interpreter written in BrainFlow (Can be interpreted by the sample and contains at least one meaningful ^ = or &): Score / 3
Interpreter written in BrainF**k: Score / 2
Doesn't contain any English letters (in either upper or lower case): Score - 20
Doesn't contain any of the BrainFlow / BFk commands in the interpreter itself: Score - 50
Example
An example Java interpreter:
import java.util.Scanner;
public class Interpreter {
private String exp;
private int[] values = new int[256];
private int index = 0;
private Scanner in;
public Interpreter(String exp, Scanner in){
this.exp = exp;
this.in = in;
}
public void run(){
//Reset index and values
for(int i = 0; i < values.length; i++){
values[i] = 0;
}
this.index = 0;
System.out.println("Starting...");
this.process(this.exp, false);
System.out.println("\nDone.");
}
private void process(String str, boolean loop){
boolean running = loop;
do{
for(int i = 0; i < str.length(); i++){
switch(str.charAt(i)){
case '>':increaseIndex();break;
case '<':decreaseIndex();break;
case '+':increaseValue();break;
case '-':decreaseValue();break;
case '[':
String s = str.substring(i);
int j = this.getClosingIndex(s);
if(this.values[this.index] == 0){
i +=j;
break;
}
process(s.substring(1, j), true);
i += j;
break;
case '.':
int v = this.values[this.index];
System.out.print((char)v);
break;
case ',':this.values[this.index] = this.in.next().charAt(0);break;
case '^':this.index = this.values[this.index];break;// Jumps to the index specified in the current cell.
case '=':this.values[index] = this.index;break;// Sets the value at cell #x to x
case '&':this.values[index] = this.values[this.values[index]];break;// If cell contains X, makes value of current cell equal to value in cell X
default:
//Ignore others
break;
}
}
if(this.values[this.index] == 0){
running = false;
}
}while(running);
}
private void increaseIndex(){
if(++this.index >= this.values.length){
this.index = 0;
}
}
private void decreaseIndex(){
if(--this.index < 0){
this.index = this.values.length - 1;
}
}
private void increaseValue(){
int newVal = this.values[this.index] + 1;
if(newVal >= this.values.length){
newVal = 0;
}
this.values[this.index] = newVal;
}
private void decreaseValue(){
int newVal = this.values[this.index] - 1;
if(newVal < 0){
newVal = this.values.length - 1;
}
this.values[this.index] = newVal;
}
private int getClosingIndex(String str){
int openings = 0;
int closings = 0;
for(int i = 0; i < str.length(); i++){
char c = str.charAt(i);
if(c == '['){
openings++;
}else if(c == ']'){
closings++;
}
if(openings == closings){
return i;
}
}
return -1;
}
}
Not even close to golfed but should provide a good starting point.
Lowest final score wins, where score is number of bytes in your program after the applicable Challenge reductions have been taken into account.
Testing
The following BrainFlow program should print the specified output after reading a '+' char from stdin:
<<,++++[>++++[>++++<-]<-] Set cell #0 to a value dependent on input
>>>+[[-]&>=]+& Set every other cell to that value
[ Start loop
+^ Add one to current value and jump to that cell index
. Print the value at that cell
& Copy value from specified cell
] End loop
Output:
ðñðòñðòðôóòñóñôóðòõóñõðôôóòñööõôöðóöðõðùõñô÷ùõóñöóùñô÷øôøõôòöõóðòöóñ÷ðõôûôòú÷úø÷öùøöùñøðùúðûðþöûñùýøðòñ
++&to retrieve my age or+++&to retrieve the month I was born in. (Assuming of course the 64th cell is at the default value of 0) \$\endgroup\$ – spocot Aug 28 '14 at 19:52subsettoextension. Thanks for the feedback. \$\endgroup\$ – spocot Aug 28 '14 at 19:56