feat(tazjin/rlox): Implement simple conditionals r/2986

... basically just optional blocks (no else).

Change-Id: If091c6b8fdeb6c13a5f3dd284d0a9a87f9f4228d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3739
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>

1 files changed, 7 insertions, 0 deletions

diff --git a/users/tazjin/rlox/src/bytecode/opcode.rs b/users/tazjin/rlox/src/bytecode/opcode.rs
index 13e2f23939ed..accc6b3bac10 100644
--- a/users/tazjin/rlox/src/bytecode/opcode.rs
+++ b/users/tazjin/rlox/src/bytecode/opcode.rs
@@ -7,6 +7,9 @@ pub struct StackIdx(pub usize);
 #[derive(Clone, Copy, Debug)]
 pub struct CodeIdx(pub usize);
 
+#[derive(Clone, Copy, Debug)]
+pub struct CodeOffset(pub usize);
+
 #[derive(Debug)]
 pub enum OpCode {
     /// Push a constant onto the stack.
@@ -45,4 +48,8 @@ pub enum OpCode {
     OpSetGlobal(ConstantIdx),
     OpGetLocal(StackIdx),
     OpSetLocal(StackIdx),
+
+    // Control flow
+    OpJumpPlaceholder(bool),
+    OpJumpIfFalse(CodeOffset),
 }