From 3f4af2defee4bcffbd02e979d15acb8574a1bd34 Mon Sep 17 00:00:00 2001
From: Alan Lawrence <alan.lawrence@cambridgequantum.com>
Date: Fri, 10 May 2024 11:00:57 +0100
Subject: [PATCH] Rm singly-impl'd TypeParametrised, rm Concrete

---
 hugr/src/extension.rs                       | 12 ------------
 hugr/src/extension/declarative/signature.rs |  2 +-
 hugr/src/extension/declarative/types.rs     |  2 +-
 hugr/src/extension/type_def.rs              | 10 ++++------
 4 files changed, 6 insertions(+), 20 deletions(-)

diff --git a/hugr/src/extension.rs b/hugr/src/extension.rs
index 4c4d27ea2..69e0f1ab5 100644
--- a/hugr/src/extension.rs
+++ b/hugr/src/extension.rs
@@ -232,18 +232,6 @@ impl CustomConcrete for CustomType {
     }
 }
 
-/// Type-parametrised functionality shared between [`TypeDef`] and [`OpDef`].
-trait TypeParametrised {
-    /// The concrete object built by binding type arguments to parameters
-    type Concrete: CustomConcrete;
-    /// The extension-unique name.
-    fn name(&self) -> &<Self::Concrete as CustomConcrete>::Identifier;
-    /// Type parameters.
-    fn params(&self) -> &[TypeParam];
-    /// The parent extension.
-    fn extension(&self) -> &ExtensionId;
-}
-
 /// A constant value provided by a extension.
 /// Must be an instance of a type available to the extension.
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
diff --git a/hugr/src/extension/declarative/signature.rs b/hugr/src/extension/declarative/signature.rs
index a1c6befba..df1aaab3b 100644
--- a/hugr/src/extension/declarative/signature.rs
+++ b/hugr/src/extension/declarative/signature.rs
@@ -12,7 +12,7 @@ use serde::{Deserialize, Serialize};
 use smol_str::SmolStr;
 
 use crate::extension::prelude::PRELUDE_ID;
-use crate::extension::{CustomValidator, ExtensionSet, SignatureFunc, TypeDef, TypeParametrised};
+use crate::extension::{CustomValidator, ExtensionSet, SignatureFunc, TypeDef};
 use crate::types::type_param::TypeParam;
 use crate::types::{CustomType, FunctionType, PolyFuncType, Type, TypeRow};
 use crate::Extension;
diff --git a/hugr/src/extension/declarative/types.rs b/hugr/src/extension/declarative/types.rs
index c90eb08e7..fb624b6f7 100644
--- a/hugr/src/extension/declarative/types.rs
+++ b/hugr/src/extension/declarative/types.rs
@@ -7,7 +7,7 @@
 //! [specification]: https://github.com/CQCL/hugr/blob/main/specification/hugr.md#declarative-format
 //! [`ExtensionSetDeclaration`]: super::ExtensionSetDeclaration
 
-use crate::extension::{TypeDef, TypeDefBound, TypeParametrised};
+use crate::extension::{TypeDef, TypeDefBound};
 use crate::types::type_param::TypeParam;
 use crate::types::{CustomType, TypeBound, TypeName};
 use crate::Extension;
diff --git a/hugr/src/extension/type_def.rs b/hugr/src/extension/type_def.rs
index 950251843..5ca9e2f7c 100644
--- a/hugr/src/extension/type_def.rs
+++ b/hugr/src/extension/type_def.rs
@@ -1,7 +1,7 @@
 use std::collections::hash_map::Entry;
 
 use super::{CustomConcrete, ExtensionBuildError};
-use super::{Extension, ExtensionId, SignatureError, TypeParametrised};
+use super::{Extension, ExtensionId, SignatureError};
 
 use crate::types::{least_upper_bound, CustomType, TypeName};
 
@@ -122,12 +122,10 @@ impl TypeDef {
             }
         }
     }
-}
-
-impl TypeParametrised for TypeDef {
-    type Concrete = CustomType;
 
-    fn params(&self) -> &[TypeParam] {
+    /// The static parameters to the TypeDef; a [TypeArg] appropriate for each
+    /// must be provided to produce an actual type.
+    pub fn params(&self) -> &[TypeParam] {
         &self.params
     }