implement basic vm runner

2 files changed, 38 insertions, 11 deletions

diff --git a/src/vm/core.js b/src/vm/core.js
index a8fbce7..6363a60 100644
--- a/src/vm/core.js
+++ b/src/vm/core.js
@@ -133,6 +133,21 @@ class Core {
 		const index = this.getLocation(pc, address);
 		return this.data[index];
 	}
+
+
+	pretty(ins) {
+		const prettyMode = {
+			'immediate':    '#',
+			'direct':       ' ',
+			'indirect':     '@',
+			'predecrement': '<',
+		};
+
+		return `\
+${ins.opcode} \
+${prettyMode[ins.a.mode]}${ins.a.value}, \
+${prettyMode[ins.b.mode]}${ins.b.value}`;
+	}
 }
 
 
diff --git a/src/vm/vm.js b/src/vm/vm.js
index 6add546..eea949a 100644
--- a/src/vm/vm.js
+++ b/src/vm/vm.js
@@ -23,7 +23,12 @@ class Warrior {
 	next() {
 		const pc = this.queue[0];
 		this.queue = this.queue.slice(1);
-		return next;
+		return pc;
+	}
+
+	peek() {
+		const pc = this.queue[0];
+		return pc;
 	}
 };
 
@@ -38,7 +43,8 @@ class RedcodeVm {
 	step() {
 		let running = 0;
 
-		for (let warrior of this.warriors) {
+		for (let i=0; i<this.warriors.length; i++) {
+			const warrior = this.warriors[i];
 			if (warrior.isDead()) {
 				continue;
 			} else {
@@ -48,6 +54,7 @@ class RedcodeVm {
 			const pc = warrior.next();
 			const ins = this.core.data[pc];
 			let next;
+			console.log(i, this.core.pretty(ins));
 			switch(ins.opcode) {
 				case 'DAT':
 					next = DAT(this.core, pc, ins);
@@ -85,25 +92,30 @@ class RedcodeVm {
 				default:
 					throw `core corruption: bad instruction ${ins}`
 			}
+
+			warrior.append(next);
 		}
 		
 		return running;
 	}
 
+	warriorsAlive() {
+		return this.warriors.reduce(
+			(count, warrior) => warrior.isDead() ? count : count+1,
+			0
+		);
+	}
+
 	run(maxSteps) {
 		let steps = 0;
-		let running = this.warriors.length;
-		while(running > 0 && steps < maxSteps) {
-			running = this.step();
+		while(this.warriorsAlive() > 1 && steps < maxSteps) {
+			this.step();
 			steps += 1;
 		}
 
-		if (running !== 0) {
-			console.log("draw, maximum steps exceeded");
-		}
-		for (let i=0; i<this.warriors.length; i++) {
-			console.log(`${i} running: ${!this.warriors[i].isDead()}`);
-		}
+		return this.warriors.map(
+			(w, i) => ({ warrior: i, alive: !w.isDead() })
+		);
 	}
 };