Use Opaque over Alias

crates/compiler/types/src/types.rs

@@ -4,6 +4,7 @@ use crate::subs::{
     GetSubsSlice, RecordFields, Subs, UnionTags, VarStore, Variable, VariableSubsSlice,
 };
 use roc_collections::all::{HumanIndex, ImMap, ImSet, MutMap, MutSet, SendMap};
+use roc_collections::VecMap;
 use roc_error_macros::internal_error;
 use roc_module::called_via::CalledVia;
 use roc_module::ident::{ForeignSymbol, Ident, Lowercase, TagName};
@@ -2055,7 +2056,31 @@ impl From<&AliasVar> for OptAbleVar {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug)]
+pub struct Opaque {
+    pub region: Region,
+    pub type_variables: Vec<Loc<AliasVar>>,
+
+    /// lambda set variables, e.g. the one annotating the arrow in
+    /// a |c|-> b
+    pub lambda_set_variables: Vec<LambdaSet>,
+    pub recursion_variables: MutSet<Variable>,
+    pub typ: Type,
+    pub kind: AliasKind,
+
+    pub supports: Vec<OpaqueSupports>,
+}
+
+#[derive(Clone, Debug)]
+pub enum OpaqueSupports {
+    Derived(Symbol),
+    Implemented {
+        ability_name: Symbol,
+        impls: VecMap<Symbol, Symbol>,
+    },
+}
+
+#[derive(Clone, Debug)]
 pub struct Alias {
     pub region: Region,
     pub type_variables: Vec<Loc<AliasVar>>,