godel init foo

3 files changed, 91 insertions, 0 deletions

diff --git a/godel/js/main.js b/godel/js/main.js
new file mode 100644
index 0000000..000ce7a
--- /dev/null
+++ b/godel/js/main.js
@@ -0,0 +1,5 @@
+const MESSAGES = {};
+
+// -- the "real" code
+
+const state = new Observable();
diff --git a/godel/js/observable.js b/godel/js/observable.js
new file mode 100644
index 0000000..1299fc6
--- /dev/null
+++ b/godel/js/observable.js
@@ -0,0 +1,14 @@
+class Observable {
+  constructor() {
+    this.observers = [];
+  }
+  subscribe(f) {
+    this.observers.push(f);
+  }
+  unsubscribe(f) {
+    this.observers = this.observers.filter((subscriber) => subscriber !== f);
+  }
+  notify(data) {
+    this.observers.forEach((observer) => observer(data));
+  }
+}
diff --git a/godel/js/turing_machine.js b/godel/js/turing_machine.js
new file mode 100644
index 0000000..a61b43a
--- /dev/null
+++ b/godel/js/turing_machine.js
@@ -0,0 +1,72 @@
+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;
+  }
+}