refactor(tazjin/rlox): Introduce newtypes for various indices r/2980

Since this code is essentially a fairly plain translation from C, it
is a bit confusing to deal with the original untyped code. This is an
attempt to try and clean some of it up.

Change-Id: Icd21f531932e1a811c0d6dbf2e9acba61ca9c45d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3734
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>

1 files changed, 4 insertions, 4 deletions

diff --git a/users/tazjin/rlox/src/bytecode/chunk.rs b/users/tazjin/rlox/src/bytecode/chunk.rs
index 7132be430a..b9a3994fe1 100644
--- a/users/tazjin/rlox/src/bytecode/chunk.rs
+++ b/users/tazjin/rlox/src/bytecode/chunk.rs
@@ -1,6 +1,6 @@
 use std::ops::Index;
 
-use super::opcode::OpCode;
+use super::opcode::{ConstantIdx, OpCode};
 use super::value;
 
 // In the book, this type is a hand-rolled dynamic array
@@ -38,8 +38,8 @@ impl Chunk {
         idx
     }
 
-    pub fn constant(&self, idx: usize) -> &value::Value {
-        self.constants.index(idx)
+    pub fn constant(&self, idx: ConstantIdx) -> &value::Value {
+        self.constants.index(idx.0)
     }
 
     fn add_line(&mut self, line: usize) {
@@ -79,7 +79,7 @@ pub fn disassemble_instruction(chunk: &Chunk, offset: usize) {
 
     match chunk.code.index(offset) {
         OpCode::OpConstant(idx) => {
-            println!("OpConstant({}) '{:?}'", *idx, chunk.constant(*idx))
+            println!("OpConstant({:?}) '{:?}'", idx, chunk.constant(*idx))
         }
         op => println!("{:?}", op),
     }