Fix replace (#52)

Author: matth2k

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "safety-net"
-version = "0.2.7"
+version = "0.2.8"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 

src/netlist.rs

@@ -798,16 +798,16 @@ where
     ///
     /// # Panics
     ///
-    /// Panics if either `self` or `other` is a multi-output circuit node.
+    /// Panics if either `self` is a multi-output circuit node.
     /// Panics if the weak reference to the netlist is lost.
-    pub fn replace_uses_with(self, other: &Self) -> Result<Object<I>, Error> {
+    pub fn replace_uses_with(self, other: &DrivenNet<I>) -> Result<Object<I>, Error> {
         let netlist = self
             .netref
             .borrow()
             .owner
             .upgrade()
             .expect("NetRef is unlinked from netlist");
-        netlist.replace_net_uses(self, other)
+        netlist.replace_net_uses(self.into(), other)
     }
 
     /// Clears the attribute with the given key on this circuit node.
@@ -1364,17 +1364,25 @@ where
     }
 
     /// Replaces the uses of a circuit node with another circuit node. The [Object] stored at `of` is returned.
-    /// Panics if `of` and  `with` are not single-output nodes.
-    pub fn replace_net_uses(&self, of: NetRef<I>, with: &NetRef<I>) -> Result<Object<I>, Error> {
-        let unwrapped = of.clone().unwrap();
+    pub fn replace_net_uses(
+        &self,
+        of: DrivenNet<I>,
+        with: &DrivenNet<I>,
+    ) -> Result<Object<I>, Error> {
+        let unwrapped = of.clone().unwrap().unwrap();
         if Rc::strong_count(&unwrapped) > 3 {
-            return Err(Error::DanglingReference(of.nets().collect()));
+            return Err(Error::DanglingReference(of.unwrap().nets().collect()));
         }
 
-        let old_tag: DrivenNet<I> = of.clone().into();
-        let old_index = old_tag.get_operand();
-        let new_tag: DrivenNet<I> = with.clone().into();
-        let new_index = new_tag.get_operand();
+        let old_index = of.get_operand();
+
+        if let Some(v) = self.outputs.borrow().get(&old_index)
+            && *v == *of.as_net()
+        {
+            return Err(Error::NonuniqueNets(vec![v.clone()]));
+        }
+
+        let new_index = with.get_operand();
         let objects = self.objects.borrow();
         for oref in objects.iter() {
             let operands = &mut oref.borrow_mut().operands;
@@ -1396,7 +1404,7 @@ where
             self.outputs.borrow_mut().insert(new_index, v.clone());
         }
 
-        Ok(of.unwrap().borrow().get().clone())
+        Ok(of.unwrap().unwrap().borrow().get().clone())
     }
 }
 

tests/analysis.rs

@@ -41,7 +41,11 @@ fn test_detect_cycles() {
     let inverted = netlist
         .insert_gate(inverter, "inst_0".into(), std::slice::from_ref(&input))
         .unwrap();
-    assert!(netlist.replace_net_uses(input.unwrap(), &inverted).is_ok());
+    assert!(
+        netlist
+            .replace_net_uses(input, &inverted.get_output(0))
+            .is_ok()
+    );
 
     // Now there is a cycle.
     // We replaced the inverter input with invert output.

tests/api.rs

@@ -363,7 +363,11 @@ fn test_replace_gate_bad() {
     let or_gate = netlist
         .insert_gate(or_gate, "inst_0".into(), &inputs)
         .unwrap();
-    assert!(netlist.replace_net_uses(and_gate, &or_gate).is_ok());
+    assert!(
+        netlist
+            .replace_net_uses(and_gate.into(), &or_gate.into())
+            .is_ok()
+    );
     // Both the AND and OR gate are driving the same wire name (subtle).
     // The instance name has to be different, or the user has to manualy rename it.
     // Will need to consider how to make this more user-friendly.
@@ -379,7 +383,11 @@ fn test_replace_gate() {
     let or_gate = netlist
         .insert_gate(or_gate, "inst_0".into(), &inputs)
         .unwrap();
-    assert!(netlist.replace_net_uses(and_gate, &or_gate).is_ok());
+    assert!(
+        netlist
+            .replace_net_uses(and_gate.into(), &or_gate.get_output(0))
+            .is_ok()
+    );
     assert!(netlist.clean().is_err());
     or_gate.set_instance_name("inst_1".into());
     or_gate.as_net_mut().set_identifier("inst_1_Y".into());

tests/edits.rs

@@ -48,7 +48,7 @@ fn test_replace() {
     let inverted = netlist
         .insert_gate(inverter, "inst_0".into(), std::slice::from_ref(&input))
         .unwrap();
-    assert!(netlist.replace_net_uses(input.unwrap(), &inverted).is_ok());
+    assert!(netlist.replace_net_uses(input, &inverted.into()).is_ok());
     assert_verilog_eq!(
         netlist.to_string(),
         "module example (
@@ -87,7 +87,7 @@ fn test_replace2() {
     // This errors, because input is not safe to delete. No replace is done.
     assert!(
         netlist
-            .replace_net_uses(input.clone().unwrap(), &inverted)
+            .replace_net_uses(input.clone(), &inverted.get_output(0))
             .is_err()
     );
     inverted.find_input(&"I".into()).unwrap().connect(input);