From c3705d81862c688a5810b8afde35a70f1e476ce8 Mon Sep 17 00:00:00 2001
From: Graham Kelly <gkgoat6700@gmail.com>
Date: Fri, 12 Jan 2024 15:39:19 -0500
Subject: [PATCH] public op io

---
 src/frontend.rs  |  4 ++--
 src/lib.rs       |  2 +-
 src/op_traits.rs | 10 ++++++++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/frontend.rs b/src/frontend.rs
index 4b66d7a..0c21fab 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -1674,8 +1674,8 @@ impl<'a, 'b> FunctionBodyBuilder<'a, 'b> {
     }
 
     fn emit(&mut self, op: Operator, loc: SourceLoc) -> Result<()> {
-        let inputs = op_inputs(self.module, &self.op_stack[..], &op)?;
-        let outputs = op_outputs(self.module, &self.op_stack[..], &op)?;
+        let inputs = op_inputs(self.module, Some(&self.op_stack[..]), &op)?;
+        let outputs = op_outputs(self.module, Some(&self.op_stack[..]), &op)?;
 
         log::trace!(
             "emit into block {:?}: op {:?} inputs {:?}",
diff --git a/src/lib.rs b/src/lib.rs
index a5b038f..870f51c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,7 +11,7 @@ pub mod entity;
 mod errors;
 mod frontend;
 mod ir;
-mod op_traits;
+pub mod op_traits;
 mod ops;
 pub mod passes;
 pub mod pool;
diff --git a/src/op_traits.rs b/src/op_traits.rs
index 8e6a887..8c44e74 100644
--- a/src/op_traits.rs
+++ b/src/op_traits.rs
@@ -7,7 +7,7 @@ use std::borrow::Cow;
 
 pub fn op_inputs(
     module: &Module,
-    op_stack: &[(Type, Value)],
+    op_stack: Option<&[(Type, Value)]>,
     op: &Operator,
 ) -> Result<Cow<'static, [Type]>> {
     match op {
@@ -24,6 +24,9 @@ pub fn op_inputs(
         }
 
         &Operator::Select => {
+            let Some(op_stack) = op_stack else{
+                anyhow::bail!("selects cannot be typed with no stack");
+            };
             let val_ty = op_stack[op_stack.len() - 2].0;
             Ok(vec![val_ty, val_ty, Type::I32].into())
         }
@@ -226,7 +229,7 @@ pub fn op_inputs(
 
 pub fn op_outputs(
     module: &Module,
-    op_stack: &[(Type, Value)],
+    op_stack: Option<&[(Type, Value)]>,
     op: &Operator,
 ) -> Result<Cow<'static, [Type]>> {
     match op {
@@ -241,6 +244,9 @@ pub fn op_outputs(
         }
 
         &Operator::Select => {
+            let Some(op_stack) = op_stack else{
+                anyhow::bail!("selects cannot be typed with no stack");
+            };
             let val_ty = op_stack[op_stack.len() - 2].0;
             Ok(vec![val_ty].into())
         }