implement error type and new ideas

backend/src/core/interpreter.rs

@@ -5,7 +5,10 @@ use crate::{
         mem::Memory,
         registers::Registers,
     },
-    utils::access::is_address_error,
+    utils::{
+        access::is_address_error,
+        error::{Error, Severity, Type::UnhandledInstruction},
+    },
 };
 
 pub struct Interpreter {
@@ -59,16 +62,21 @@ impl Cpu for Interpreter {
         Some(instr)
     }
 
-    fn execute(&mut self, mem: &Memory) -> Result<u32, String> {
+    fn step(&mut self, mem: &Memory) -> Result<u32, Error> {
         if let Some(instr) = self.fetch_then_advance(mem) {
-            self.decode(instr)?;
+            self.decode_execute(instr)?;
         }
 
         Ok(1)
     }
 
-    fn decode(&mut self, instr: Instruction) -> Result<(), String> {
-        todo!("decode")
+    fn decode_execute(&mut self, instr: Instruction) -> Result<(), Error> {
+        match instr.opcode() {
+            _ => Err(Error {
+                severity: Severity::Error,
+                err_type: UnhandledInstruction(instr),
+            }),
+        }
     }
 
     fn reset(&mut self) {