DRAFT: datalog style constant folding solver skeleton

hugr-core/src/lib.rs

@@ -14,6 +14,7 @@ pub mod extension;
 pub mod hugr;
 pub mod macros;
 pub mod ops;
+pub mod partial_value;
 pub mod std_extensions;
 pub mod types;
 pub mod utils;

hugr-core/src/ops/constant.rs

@@ -98,7 +98,7 @@ impl AsRef<Value> for Const {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 #[serde(tag = "v")]
 /// A value that can be stored as a static constant. Representing core types and
 /// extension types.
@@ -136,6 +136,49 @@ pub enum Value {
     },
 }
 
+impl PartialEq for Value {
+    fn eq(&self, other: &Self) -> bool {
+        let cmp_tuple_sum =
+            |tuple_values: &[Value], tag: usize, sum_values: &[Value], sum_type: &SumType| {
+                tag == 0 && sum_type.num_variants() == 1 && tuple_values == sum_values
+            };
+        match (self, other) {
+            (Self::Extension { e: e1 }, Self::Extension { e: e2 }) => e1 == e2,
+            (Self::Function { hugr: h1 }, Self::Function { hugr: h2 }) => h1 == h2,
+            (Self::Tuple { vs: v1 }, Self::Tuple { vs: v2 }) => v1 == v2,
+            (
+                Self::Sum {
+                    tag: t1,
+                    values: v1,
+                    sum_type: s1,
+                },
+                Self::Sum {
+                    tag: t2,
+                    values: v2,
+                    sum_type: s2,
+                },
+            ) => t1 == t2 && v1 == v2 && s1 == s2,
+            (
+                Self::Tuple { vs },
+                Self::Sum {
+                    tag,
+                    values,
+                    sum_type,
+                },
+            )
+            | (
+                Self::Sum {
+                    tag,
+                    values,
+                    sum_type,
+                },
+                Self::Tuple { vs },
+            ) => cmp_tuple_sum(vs, *tag, values, sum_type),
+            _ => false,
+        }
+    }
+}
+
 /// An opaque newtype around a [`Box<dyn CustomConst>`](CustomConst).
 ///
 /// This type has special serialization behaviour in order to support

hugr-core/src/ops/module.rs

@@ -128,7 +128,7 @@ impl OpTrait for AliasDefn {
 }
 
 /// A type alias declaration. Resolved at link time.
-#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(test, derive(proptest_derive::Arbitrary))]
 pub struct AliasDecl {
     /// Alias name