simponic.xyz/turing-machine/js/turing_machine.js

73 lines
1.5 KiB
JavaScript

class TuringMachine {
constructor(tape = [], rules = [], initialState = "q0", acceptState = "f") {
this.tape = tape;
this.rules = this.parseRules(rules);
this.state = initialState;
this.head = 0;
this.acceptState = acceptState;
this.iteration = 0;
}
getStateStatus() {
return `State: ${this.state}, Step: ${this.iteration}`;
}
getHead() {
return this.head;
}
getState() {
return this.state;
}
getTapeAtCell(idx) {
return this.tape[idx];
}
setTapeAtCell(idx, val) {
this.tape[idx] = val;
}
isAccepting() {
return this.state == this.acceptState;
}
parseRules(rules) {
const parsedRules = {};
for (const [currentState, readSymbol, action, newState] of rules) {
const key = `${currentState},${readSymbol}`;
const value = `${newState},${action}`;
parsedRules[key] = value;
}
return parsedRules;
}
step() {
const currentSymbol = this.tape[this.head];
const key = `${this.state},${currentSymbol}`;
if (!(key in this.rules)) {
return false;
}
const rule = this.rules[key];
const [newState, action] = rule.split(",");
this.state = newState;
this.iteration++;
if (action === "R") {
this.head += 1;
} else if (action === "L") {
this.head -= 1;
} else {
this.tape[this.head] = action;
}
if (this.isAccepting()) {
return false;
}
return this.head >= 0 && this.head < this.tape.length;
}
}