From 8f0da8a7f7f08323b33dc31f869439aeb6537950 Mon Sep 17 00:00:00 2001
From: Muhammad Nauman Raza <devraza.hazard643@slmail.me>
Date: Sun, 26 Jan 2025 09:17:39 +0000
Subject: [PATCH] feat: proper branching and support for instruction-line loops

Branching works through changing the value of the program counter, which
represents the line number to process.
---
 src/main.rs | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 440b9ac..8f67991 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,10 +7,19 @@ fn process(
     accumulator: &mut i64,
     memory: &mut HashMap<String, i64>,
     labels: &HashMap<String, usize>,
+    pc: &mut usize,
 ) -> usize {
     let ops: Vec<String> = line.trim().split_whitespace().map(String::from).collect();
 
-    match ops[0].as_str() {
+    let options: Vec<&str>;
+    if ops.len() > 1 {
+        options = vec![ops[0].as_str(), ops[1].as_str()];
+    } else {
+        options = vec![ops[0].as_str()];
+    }
+    
+    for op in options {
+    match op {
         "INP" => {
             let mut s = String::new();
             io::stdin().read_line(&mut s).unwrap();
@@ -21,7 +30,11 @@ fn process(
             memory.insert(ops[1].clone(), *accumulator);
         }
         "LDA" => {
-            *accumulator = *memory.get(&ops[1]).unwrap_or(&0);
+            if ops.len() > 1 {
+                *accumulator = *memory.get(&ops[2]).unwrap_or(&0);
+            } else {
+                *accumulator = *memory.get(&ops[1]).unwrap_or(&0);
+            }
         }
         "ADD" => {
             if let Ok(value) = ops[1].parse::<i64>() {
@@ -38,7 +51,7 @@ fn process(
             }
         }
         "BRA" => {
-            return *labels.get(&ops[1]).unwrap_or(&0);
+            *pc = *labels.get(&ops[1]).unwrap();
         }
         "HLT" => std::process::exit(0),
         _ => {
@@ -50,6 +63,7 @@ fn process(
             }
         }
     }
+}
 
     return 0;
 }
@@ -71,7 +85,7 @@ fn main() -> io::Result<()> {
         if ops.len() > 1 && ops[1] == "DAT" {
             labels.insert(ops[0].clone(), index);
         } else if ops.len() > 1 {
-            labels.insert(ops[0].clone(), index);
+            labels.insert(ops[1].clone(), index);
         }
         code.push(line);
     }
@@ -79,7 +93,7 @@ fn main() -> io::Result<()> {
     let mut pc: usize = 0;
     while pc < code.len() {
         let line = &code[pc];
-        let next_pc = process(line.to_string(), &mut accumulator, &mut memory, &labels);
+        let next_pc = process(line.to_string(), &mut accumulator, &mut memory, &labels, &mut pc);
         if next_pc != 0 {
             pc = next_pc;
         } else {