If(j)invert()if(l)change()if(q)input()if(t)output(x);

INTERPRETER
Especifications:

J - invert the bit pointed L - invert the pointer Q - input and put in the pointer T - output the pointer

Interpreter in c:

int[] mem = [0, 0]; int pointer = 0; int ip = 0; for{ char x = scanf('%s', x); switch(x){ case('j'){ if(mem[pointer] == 0){ mem[pointer] = 1;}else{ mem[pointer] = 0;}break;} case('l'){ if(pointer == 0){ pointer = 1; }else{ pointer = 0;}break;} case('q'){ mem[pointer] = scanf('%i', mem[pointer]);break;} case('t'){ printf('%c', mem[pointer]); break;} default{ printf('%c', x); break;} } }

(It uses scanf, and it needs to be better)

SAMPLES
Hello World: He11o Wor1d More elaborated hello world: Hell11ojl ljworl1d Any program that don't uses the characters jlqt is already a quote.

Cat is limited to QTQTQTQTQTQTQTQTQTQTQTQTQTQTQTQTQTQTQT or more.

Add more samples, please...