From ba69b1070bd638077d17fe71ff3c2c73666ef85f Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 16 Jan 2023 11:46:00 +1100
Subject: [PATCH] ld_immediate_word

---
 src/main.rs | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 8dc46bf..495a58a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -116,23 +116,18 @@ struct CPU {
 impl CPU {
     fn exec_next(&mut self) -> u8 {
         let opcode = self.next_opcode();
-        println!("opcode: {:#X}", opcode);
-
         match opcode {
             0x0 => {
                 // noop
             }
             0x01 => {
-                self.state.bc.as_u8s.left = self.next_opcode();
-                self.state.bc.as_u8s.right = self.next_opcode();
+                self.state.bc = self.ld_immediate_word();
             }
             0x11 => {
-                self.state.de.as_u8s.left = self.next_opcode();
-                self.state.de.as_u8s.right = self.next_opcode();
+                self.state.de = self.ld_immediate_word();
             }
             0x21 => {
-                self.state.de.as_u8s.left = self.next_opcode();
-                self.state.de.as_u8s.right = self.next_opcode();
+                self.state.hl = self.ld_immediate_word();
             }
             0x2C => {
                 unsafe {
@@ -145,9 +140,7 @@ impl CPU {
                 };
             }
             0xC3 => {
-                let (a, b) = (self.next_opcode(), self.next_opcode());
-                self.state.pc.as_u8s.left = a;
-                self.state.pc.as_u8s.right = b;
+                self.state.pc = self.ld_immediate_word();
             }
             _ => {
                 panic!("unimplemented opcode: {:#X}", opcode);
@@ -155,6 +148,7 @@ impl CPU {
         };
         return opcode;
     }
+
     fn next_opcode(&mut self) -> u8 {
         unsafe {
             let opcode = self.memory.get(self.state.pc.as_u16);
@@ -162,6 +156,15 @@ impl CPU {
             return opcode;
         };
     }
+
+    fn ld_immediate_word(&mut self) -> Register {
+        Register {
+            as_u8s: Inner {
+                left: self.next_opcode(),
+                right: self.next_opcode(),
+            },
+        }
+    }
 }
 
 fn main() {
@@ -175,10 +178,10 @@ fn main() {
     };
     loop {
         cpu.exec_next();
-        pause();
     }
 }
 
+#[allow(dead_code)]
 fn pause() {
     io::stdin().read_line(&mut String::new()).unwrap();
 }