Derive PartialEq for ConstValue (impl only for dyn CustomConst)

Add extra tuple to workaround rust-lang/rust#78808 Rename CustomConst::(eq => equal_consts) to disambiguate
CQCL · Jul 31, 2023 · b6f65ca · b6f65ca
1 parent 26a4f1a
commit b6f65ca
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Showing 2 changed files with 11 additions and 35 deletions.
diff --git a/src/hugr/typecheck.rs b/src/hugr/typecheck.rs
@@ -155,7 +155,7 @@ pub fn typecheck_const(typ: &ClassicType, val: &ConstValue) -> Result<(), ConstT
  (Container::Sum(_), _) => {
  Err(ConstTypeError::TypeMismatch(ty.clone(), tm.const_type()))
  }
- (Container::Opaque(ty), ConstValue::Opaque(ty_act, _val)) => {
+ (Container::Opaque(ty), ConstValue::Opaque((ty_act, _val))) => {
  if ty_act != ty {
  return Err(ConstTypeError::TypeMismatch(
  ty.clone().into(),

diff --git a/src/ops/constant.rs b/src/ops/constant.rs
@@ -48,7 +48,7 @@ pub(crate) const HUGR_MAX_INT_WIDTH: HugrIntWidthStore =
 ///
 /// TODO: Add more constants
 /// TODO: bigger/smaller integers.
-#[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
+#[derive(Clone, Debug, PartialEq, serde::Serialize, serde::Deserialize)]
 #[non_exhaustive]
 #[allow(missing_docs)]
 pub enum ConstValue {
@@ -69,38 +69,14 @@ pub enum ConstValue {
  },
  /// A tuple of constant values.
  Tuple(Vec<ConstValue>),
- /// An opaque constant value, with cached type.
- Opaque(CustomType, Box<dyn CustomConst>),
+ /// An opaque constant value, with cached type
+ // Note: the extra level of tupling is to avoid https://github.com/rust-lang/rust/issues/78808
+ Opaque((CustomType, Box<dyn CustomConst>)),
 }
 
-impl PartialEq for ConstValue {
+impl PartialEq for dyn CustomConst {
  fn eq(&self, other: &Self) -> bool {
- match (self, other) {
- (
- Self::Int {
- value: l0,
- width: l_width,
- },
- Self::Int {
- value: r0,
- width: r_width,
- },
- ) => l0 == r0 && l_width == r_width,
- (Self::Opaque(l0, l1), Self::Opaque(r0, r1)) => l0 == r0 && l1.eq(&**r1),
- (
- Self::Sum { tag, variants, val },
- Self::Sum {
- tag: t1,
- variants: type1,
- val: v1,
- },
- ) => tag == t1 && variants == type1 && val == v1,
-
- (Self::Tuple(v1), Self::Tuple(v2)) => v1.eq(v2),
- (Self::F64(f1), Self::F64(f2)) => f1 == f2,
-
- _ => false,
- }
+ (*self).equal_consts(other)
  }
 }
 
@@ -118,7 +94,7 @@ impl ConstValue {
  pub fn const_type(&self) -> ClassicType {
  match self {
  Self::Int { value: _, width } => HashableType::Int(*width).into(),
- Self::Opaque(_, b) => Container::Opaque((*b).custom_type()).into(),
+ Self::Opaque((_, b)) => Container::Opaque((*b).custom_type()).into(),
  Self::Sum { variants, .. } => ClassicType::new_sum(variants.clone()),
  Self::Tuple(vals) => {
  let row: Vec<_> = vals.iter().map(|val| val.const_type()).collect();
@@ -132,7 +108,7 @@ impl ConstValue {
  match self {
  Self::Int { value, width } => format!("const:int<{width}>:{value}"),
  Self::F64(f) => format!("const:float:{f}"),
- Self::Opaque(_, v) => format!("const:{}", v.name()),
+ Self::Opaque((_, v)) => format!("const:{}", v.name()),
  Self::Sum { tag, val, .. } => {
  format!("const:sum:{{tag:{tag}, val:{}}}", val.name())
  }
@@ -203,7 +179,7 @@ impl ConstValue {
 
 impl<T: CustomConst> From<T> for ConstValue {
  fn from(v: T) -> Self {
- Self::Opaque(v.custom_type(), Box::new(v))
+ Self::Opaque((v.custom_type(), Box::new(v)))
  }
 }
 
@@ -223,7 +199,7 @@ pub trait CustomConst:
  fn custom_type(&self) -> CustomType;
 
  /// Compare two constants for equality, using downcasting and comparing the definitions.
- fn eq(&self, other: &dyn CustomConst) -> bool {
+ fn equal_consts(&self, other: &dyn CustomConst) -> bool {
  let _ = other;
  false
  }