assembler: enhance error handling and tokenization logic

assembler/src/source/token.rs

@@ -5,10 +5,9 @@
 use common::prelude::*;
 
 use crate::source::{
+    opcode::Opcode,
     source_info::SourceInfo,
-    token_info::{
-        DirectiveToken, InstructionToken, LabelToken, RegisterToken, SymbolToken,
-    },
+    token_info::{DirectiveToken, LabelToken, RegisterToken, SymbolToken},
 };
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -22,7 +21,7 @@ pub enum TokenType {
     /// String literal (e.g., `"hello world"`).
     String(String),
     /// Assembly instruction (e.g., `add`, `jmp`, `nop`).
-    Instruction(InstructionToken),
+    Instruction(Opcode),
     /// Label definition (e.g., `loop_start:`).
     Label(LabelToken),
     /// Assembler directive (e.g., `.global`, `.section`, `.dw`, `.resb`).
@@ -65,11 +64,8 @@ impl Token {
     }
 
     #[must_use]
-    pub const fn instruction(mnemonic: String, source_info: SourceInfo) -> Self {
-        Self::new(
-            TokenType::Instruction(InstructionToken { mnemonic }),
-            source_info,
-        )
+    pub const fn instruction(op: Opcode, source_info: SourceInfo) -> Self {
+        Self::new(TokenType::Instruction(op), source_info)
     }
 
     #[must_use]