core: Initial implementation for const generics

nac3core/src/symbol_resolver.rs

@@ -85,7 +85,7 @@ impl SymbolValue {
                         .map(|val| SymbolValue::U64(val))
                         .map_err(|e| e.to_string())
                 } else {
-                    Err(format!("Expected {:?}, but got int", expected_ty))
+                    Err(format!("Expected {}, but got int", unifier.stringify(expected_ty)))
                 }
             }
             Constant::Tuple(t) => {

nac3core/src/toplevel/composer.rs

@@ -560,6 +560,7 @@ impl TopLevelComposer {
                         &primitive_types,
                         b,
                         vec![(*class_def_id, class_type_vars.clone())].into_iter().collect(),
+                        None,
                     )?;
 
                     if let TypeAnnotation::CustomClass { .. } = &base_ty {
@@ -894,6 +895,7 @@ impl TopLevelComposer {
                                     // NOTE: since only class need this, for function
                                     // it should be fine to be empty map
                                     HashMap::new(),
+                                    None,
                                 )?;
 
                                 let type_vars_within =
@@ -961,6 +963,7 @@ impl TopLevelComposer {
                                     // NOTE: since only class need this, for function
                                     // it should be fine to be empty map
                                     HashMap::new(),
+                                    None,
                                 )?
                             };
 
@@ -1158,6 +1161,7 @@ impl TopLevelComposer {
                                         vec![(class_id, class_type_vars_def.clone())]
                                             .into_iter()
                                             .collect(),
+                                        None,
                                     )?
                                 };
                                 // find type vars within this method parameter type annotation
@@ -1221,6 +1225,7 @@ impl TopLevelComposer {
                                 primitives,
                                 result,
                                 vec![(class_id, class_type_vars_def.clone())].into_iter().collect(),
+                                None,
                             )?;
                             // find type vars within this return type annotation
                             let type_vars_within =
@@ -1317,6 +1322,7 @@ impl TopLevelComposer {
                                 primitives,
                                 annotation.as_ref(),
                                 vec![(class_id, class_type_vars_def.clone())].into_iter().collect(),
+                                None,
                             )?;
                             // find type vars within this return type annotation
                             let type_vars_within =
@@ -1735,7 +1741,7 @@ impl TopLevelComposer {
                             .iter()
                             .map(|(_, ty)| {
                                 unifier.get_instantiations(*ty).unwrap_or_else(|| {
-                                    if let TypeEnum::TVar { name, loc, .. } = &*unifier.get_ty(*ty)
+                                    if let TypeEnum::TVar { name, loc, is_const_generic: false, .. } = &*unifier.get_ty(*ty)
                                     {
                                         let rigid = unifier.get_fresh_rigid_var(*name, *loc).0;
                                         no_ranges.push(rigid);

nac3core/src/toplevel/type_annotation.rs

@@ -1,3 +1,4 @@
+use crate::symbol_resolver::SymbolValue;
 use super::*;
 
 #[derive(Clone, Debug)]
@@ -12,6 +13,16 @@ pub enum TypeAnnotation {
     // can only be CustomClassKind
     Virtual(Box<TypeAnnotation>),
     TypeVar(Type),
+    /// A constant used in the context of a const-generic variable.
+    Constant {
+        /// The non-type variable associated with this constant.
+        ///
+        /// Invoking [Unifier::get_ty] on this type will return a [TypeEnum::TVar] representing the
+        /// const generic variable of which this constant is associated with.
+        ty: Type,
+        /// The constant value of this constant.
+        value: SymbolValue
+    },
     List(Box<TypeAnnotation>),
     Tuple(Vec<TypeAnnotation>),
 }
@@ -47,6 +58,7 @@ impl TypeAnnotation {
                     }
                 )
             }
+            Constant { value, .. } => format!("Const({value})"),
             Virtual(ty) => format!("virtual[{}]", ty.stringify(unifier)),
             List(ty) => format!("list[{}]", ty.stringify(unifier)),
             Tuple(types) => {
@@ -56,6 +68,12 @@ impl TypeAnnotation {
     }
 }
 
+/// Parses an AST expression `expr` into a [TypeAnnotation].
+///
+/// * `locked` - A [HashMap] containing the IDs of known definitions, mapped to a [Vec] of all
+/// generic variables associated with the definition.
+/// * `type_var` - The type variable associated with the type argument currently being parsed. Pass
+/// [None] when this function is invoked externally.
 pub fn parse_ast_to_type_annotation_kinds<T>(
     resolver: &(dyn SymbolResolver + Send + Sync),
     top_level_defs: &[Arc<RwLock<TopLevelDef>>],
@@ -64,6 +82,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
     expr: &ast::Expr<T>,
     // the key stores the type_var of this topleveldef::class, we only need this field here
     locked: HashMap<DefinitionId, Vec<Type>>,
+    type_var: Option<Type>,
 ) -> Result<TypeAnnotation, String> {
     let name_handle = |id: &StrRef,
                        unifier: &mut Unifier,
@@ -161,7 +180,8 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                 }
                 let result = params_ast
                     .iter()
-                    .map(|x| {
+                    .enumerate()
+                    .map(|(idx, x)| {
                         parse_ast_to_type_annotation_kinds(
                             resolver,
                             top_level_defs,
@@ -172,6 +192,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                                 locked.insert(obj_id, type_vars.clone());
                                 locked.clone()
                             },
+                            Some(type_vars[idx]),
                         )
                     })
                     .collect::<Result<Vec<_>, _>>()?;
@@ -190,6 +211,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
             };
             Ok(TypeAnnotation::CustomClass { id: obj_id, params: param_type_infos })
         };
+
     match &expr.node {
         ast::ExprKind::Name { id, .. } => name_handle(id, unifier, locked),
         // virtual
@@ -205,6 +227,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                 primitives,
                 slice.as_ref(),
                 locked,
+                None,
             )?;
             if !matches!(def, TypeAnnotation::CustomClass { .. }) {
                 unreachable!("must be concretized custom class kind in the virtual")
@@ -225,6 +248,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                 primitives,
                 slice.as_ref(),
                 locked,
+                None,
             )?;
             Ok(TypeAnnotation::List(def_ann.into()))
         }
@@ -242,6 +266,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                 primitives,
                 slice.as_ref(),
                 locked,
+                None,
             )?;
             let id =
                 if let TypeEnum::TObj { obj_id, .. } = unifier.get_ty(primitives.option).as_ref() {
@@ -275,6 +300,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                         primitives,
                         e,
                         locked.clone(),
+                        None,
                     )
                 })
                 .collect::<Result<Vec<_>, _>>()?;
@@ -290,6 +316,31 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
             }
         }
 
+        ast::ExprKind::Constant { value, .. } => {
+            let type_var = type_var.expect("Expect type variable to be present");
+
+            let ntv_ty_enum = unifier.get_ty_immutable(type_var);
+            let TypeEnum::TVar { range: underlying_ty, .. } = ntv_ty_enum.as_ref() else {
+                unreachable!()
+            };
+            let underlying_ty = underlying_ty[0];
+
+            let value = SymbolValue::from_constant(value, underlying_ty, primitives, unifier)?;
+
+            if matches!(value, SymbolValue::Str(_) | SymbolValue::Tuple(_) | SymbolValue::OptionSome(_)) {
+                return Err(format!(
+                    "expression {} is not allowed for constant type annotation (at {})",
+                    value.to_string(),
+                    expr.location
+                ))
+            }
+
+            Ok(TypeAnnotation::Constant {
+                ty: type_var,
+                value,
+            })
+        }
+
         _ => Err(format!("unsupported expression for type annotation (at {})", expr.location)),
     }
 }
@@ -308,14 +359,18 @@ pub fn get_type_from_type_annotation_kinds(
         TypeAnnotation::CustomClass { id: obj_id, params } => {
             let def_read = top_level_defs[obj_id.0].read();
             let class_def: &TopLevelDef = def_read.deref();
-            if let TopLevelDef::Class { fields, methods, type_vars, .. } = class_def {
+            let TopLevelDef::Class { fields, methods, type_vars, .. } = class_def else {
+                unreachable!("should be class def here")
+            };
+
             if type_vars.len() != params.len() {
-                    Err(format!(
+                return Err(format!(
                     "unexpected number of type parameters: expected {} but got {}",
                     type_vars.len(),
                     params.len()
                 ))
-                } else {
+            }
+
             let param_ty = params
                 .iter()
                 .map(|x| {
@@ -334,9 +389,8 @@ pub fn get_type_from_type_annotation_kinds(
                 // TODO: if allow type var to be applied(now this disallowed in the parse_to_type_annotation), need more check
                 let mut result: HashMap<u32, Type> = HashMap::new();
                 for (tvar, p) in type_vars.iter().zip(param_ty) {
-                            if let TypeEnum::TVar { id, range, fields: None, name, loc } =
+                    match unifier.get_ty(*tvar).as_ref() {
-                                unifier.get_ty(*tvar).as_ref()
+                        TypeEnum::TVar { id, range, fields: None, name, loc, is_const_generic: false } => {
-                            {
                             let ok: bool = {
                                 // create a temp type var and unify to check compatibility
                                 p == *tvar || {
@@ -362,8 +416,33 @@ pub fn get_type_from_type_annotation_kinds(
                                     *id
                                 ));
                             }
+                        }
+
+                        TypeEnum::TVar { id, range, name, loc, is_const_generic: true, .. } => {
+                            let ty = range[0];
+                            let ok: bool = {
+                                // create a temp type var and unify to check compatibility
+                                p == *tvar || {
+                                    let temp = unifier.get_fresh_const_generic_var(
+                                        ty,
+                                        *name,
+                                        *loc,
+                                    );
+                                    unifier.unify(temp.0, p).is_ok()
+                                }
+                            };
+                            if ok {
+                                result.insert(*id, p);
                             } else {
-                                unreachable!("must be generic type var")
+                                return Err(format!(
+                                    "cannot apply type {} to type variable {}",
+                                    unifier.stringify(p),
+                                    name.unwrap_or_else(|| format!("typevar{id}").into()),
+                                ))
+                            }
+                        }
+
+                        _ => unreachable!("must be generic type var"),
                     }
                 }
                 result
@@ -391,11 +470,19 @@ pub fn get_type_from_type_annotation_kinds(
             }
             Ok(ty)
         }
-            } else {
-                unreachable!("should be class def here")
-            }
-        }
         TypeAnnotation::Primitive(ty) | TypeAnnotation::TypeVar(ty) => Ok(*ty),
+        TypeAnnotation::Constant { ty, value, .. } => {
+            let ty_enum = unifier.get_ty(*ty);
+            let (ty, loc) = match &*ty_enum {
+                TypeEnum::TVar { range: ntv_underlying_ty, loc, is_const_generic: true, .. } => {
+                    (ntv_underlying_ty[0], loc)
+                }
+                _ => unreachable!("{} ({})", unifier.stringify(*ty), ty_enum.get_type_name()),
+            };
+
+            let var = unifier.get_fresh_constant(value.clone(), ty, *loc);
+            Ok(var)
+        }
         TypeAnnotation::Virtual(ty) => {
             let ty = get_type_from_type_annotation_kinds(
                 top_level_defs,
@@ -470,7 +557,7 @@ pub fn get_type_var_contained_in_type_annotation(ann: &TypeAnnotation) -> Vec<Ty
                 result.extend(get_type_var_contained_in_type_annotation(a));
             }
         }
-        TypeAnnotation::Primitive(..) => {}
+        TypeAnnotation::Primitive(..) | TypeAnnotation::Constant { .. } => {}
     }
     result
 }

nac3core/src/typecheck/typedef/mod.rs

@@ -134,6 +134,17 @@ pub enum TypeEnum {
         range: Vec<Type>,
         name: Option<StrRef>,
         loc: Option<Location>,
+        /// Whether this type variable refers to a const-generic variable.
+        is_const_generic: bool,
+    },
+
+    /// A constant for substitution into a const generic variable.
+    TConstant {
+        /// The value of the constant.
+        value: SymbolValue,
+        /// The underlying type of the value.
+        ty: Type,
+        loc: Option<Location>,
     },
 
     /// A tuple type.
@@ -178,6 +189,7 @@ impl TypeEnum {
         match self {
             TypeEnum::TRigidVar { .. } => "TRigidVar",
             TypeEnum::TVar { .. } => "TVar",
+            TypeEnum::TConstant { .. } => "TConstant",
             TypeEnum::TTuple { .. } => "TTuple",
             TypeEnum::TList { .. } => "TList",
             TypeEnum::TObj { .. } => "TObj",
@@ -263,6 +275,7 @@ impl Unifier {
             fields: Some(fields),
             name: None,
             loc: None,
+            is_const_generic: false,
         })
     }
 
@@ -336,7 +349,33 @@ impl Unifier {
         let id = self.var_id + 1;
         self.var_id += 1;
         let range = range.to_vec();
-        (self.add_ty(TypeEnum::TVar { id, range, fields: None, name, loc }), id)
+        (self.add_ty(TypeEnum::TVar { id, range, fields: None, name, loc, is_const_generic: false }), id)
+    }
+
+    /// Returns a fresh type representing a constant generic variable with the given underlying type
+    /// `ty`.
+    pub fn get_fresh_const_generic_var(
+        &mut self,
+        ty: Type,
+        name: Option<StrRef>,
+        loc: Option<Location>,
+    ) -> (Type, u32) {
+        let id = self.var_id + 1;
+        self.var_id += 1;
+        (self.add_ty(TypeEnum::TVar { id, range: vec![ty], fields: None, name, loc, is_const_generic: true }), id)
+    }
+
+    /// Returns a fresh type representing a [fresh constant][TypeEnum::TConstant] with the given
+    /// `value` and type `ty`.
+    pub fn get_fresh_constant(
+        &mut self,
+        value: SymbolValue,
+        ty: Type,
+        loc: Option<Location>,
+    ) -> Type {
+        assert!(matches!(self.get_ty(ty).as_ref(), TypeEnum::TObj { .. }));
+
+        self.add_ty(TypeEnum::TConstant { ty, value, loc })
     }
 
     /// Unification would not unify rigid variables with other types, but we want to do this for
@@ -412,7 +451,7 @@ impl Unifier {
     pub fn is_concrete(&mut self, a: Type, allowed_typevars: &[Type]) -> bool {
         use TypeEnum::*;
         match &*self.get_ty(a) {
-            TRigidVar { .. } => true,
+            TRigidVar { .. } | TConstant { .. } => true,
             TVar { .. } => allowed_typevars.iter().any(|b| self.unification_table.unioned(a, *b)),
             TCall { .. } => false,
             TList { ty } => self.is_concrete(*ty, allowed_typevars),
@@ -560,8 +599,8 @@ impl Unifier {
         };
         match (&*ty_a, &*ty_b) {
             (
-                TVar { fields: fields1, id, name: name1, loc: loc1, .. },
+                TVar { fields: fields1, id, name: name1, loc: loc1, is_const_generic: false, .. },
-                TVar { fields: fields2, id: id2, name: name2, loc: loc2, .. },
+                TVar { fields: fields2, id: id2, name: name2, loc: loc2, is_const_generic: false, .. },
             ) => {
                 let new_fields = match (fields1, fields2) {
                     (None, None) => None,
@@ -616,10 +655,11 @@ impl Unifier {
                         range,
                         name: name1.or(*name2),
                         loc: loc1.or(*loc2),
+                        is_const_generic: false,
                     }),
                 );
             }
-            (TVar { fields: None, range, .. }, _) => {
+            (TVar { fields: None, range, is_const_generic: false, .. }, _) => {
                 // We check for the range of the type variable to see if unification is allowed.
                 // Note that although b may be compatible with a, we may have to constrain type
                 // variables in b to make sure that instantiations of b would always be compatible
@@ -636,7 +676,7 @@ impl Unifier {
                 self.unify_impl(x, b, false)?;
                 self.set_a_to_b(a, x);
             }
-            (TVar { fields: Some(fields), range, .. }, TTuple { ty }) => {
+            (TVar { fields: Some(fields), range, is_const_generic: false, .. }, TTuple { ty }) => {
                 let len = ty.len() as i32;
                 for (k, v) in fields.iter() {
                     match *k {
@@ -666,7 +706,7 @@ impl Unifier {
                 self.unify_impl(x, b, false)?;
                 self.set_a_to_b(a, x);
             }
-            (TVar { fields: Some(fields), range, .. }, TList { ty }) => {
+            (TVar { fields: Some(fields), range, is_const_generic: false, .. }, TList { ty }) => {
                 for (k, v) in fields.iter() {
                     match *k {
                         RecordKey::Int(_) => {
@@ -681,6 +721,35 @@ impl Unifier {
                 self.unify_impl(x, b, false)?;
                 self.set_a_to_b(a, x);
             }
+
+            (TVar { id: id1, range: ty1, is_const_generic: true, .. }, TVar { id: id2, range: ty2, .. }) => {
+                let ty1 = ty1[0];
+                let ty2 = ty2[0];
+
+                if id1 != id2 {
+                    self.unify_impl(ty1, ty2, false)?;
+                }
+
+                self.set_a_to_b(a, b);
+            }
+
+            (TVar { range: ty1, is_const_generic: true, .. }, TConstant { ty: ty2, .. }) => {
+                let ty1 = ty1[0];
+
+                self.unify_impl(ty1, *ty2, false)?;
+                self.set_a_to_b(a, b);
+            }
+
+            (TConstant { value: val1, ty: ty1, .. }, TConstant { value: val2, ty: ty2, .. }) => {
+                if val1 != val2 {
+                    eprintln!("VALUE MISMATCH: lhs={val1:?} rhs={val2:?} eq={}", val1 == val2);
+                    return self.incompatible_types(a, b)
+                }
+                self.unify_impl(*ty1, *ty2, false)?;
+
+                self.set_a_to_b(a, b);
+            }
+
             (TTuple { ty: ty1 }, TTuple { ty: ty2 }) => {
                 if ty1.len() != ty2.len() {
                     return Err(TypeError::new(TypeErrorKind::IncompatibleTypes(a, b), None));
@@ -775,7 +844,14 @@ impl Unifier {
                 if id1 != id2 {
                     self.incompatible_types(a, b)?;
                 }
-                for (x, y) in zip(params1.values(), params2.values()) {
+
+                // Sort the type arguments by its UnificationKey first, since `HashMap::iter` visits
+                // all K-V pairs "in arbitrary order"
+                let (tv1, tv2) = (
+                    params1.iter().sorted_by_key(|(k, _)| *k).map(|(_, v)| v).collect_vec(),
+                    params2.iter().sorted_by_key(|(k, _)| *k).map(|(_, v)| v).collect_vec(),
+                );
+                for (x, y) in zip(tv1, tv2) {
                     if self.unify_impl(*x, *y, false).is_err() {
                         return Err(TypeError::new(TypeErrorKind::IncompatibleTypes(a, b), None));
                     };
@@ -928,6 +1004,9 @@ impl Unifier {
                 };
                 n
             }
+            TypeEnum::TConstant { value, .. } => {
+                format!("const({value})")
+            }
             TypeEnum::TTuple { ty } => {
                 let mut fields =
                     ty.iter().map(|v| self.internal_stringify(*v, obj_to_name, var_to_name, notes));
@@ -983,8 +1062,8 @@ impl Unifier {
         }
     }
 
+    /// Unifies `a` and `b` together, and set the value to the value of `b`.
     fn set_a_to_b(&mut self, a: Type, b: Type) {
-        // unify a and b together, and set the value to b's value.
         let table = &mut self.unification_table;
         let ty_b = table.probe_value(b).clone();
         table.unify(a, b);
@@ -1207,6 +1286,7 @@ impl Unifier {
                             range,
                             name: name2.or(*name),
                             loc: loc2.or(*loc),
+                            is_const_generic: false,
                         };
                         Ok(Some(self.unification_table.new_key(ty.into())))
                     }

nac3standalone/demo/interpret_demo.py

@@ -44,6 +44,12 @@ def Some(v: T) -> Option[T]:
 
 none = Option(None)
 
+class _ConstGenericMarker:
+    pass
+
+def ConstGeneric(name, constraint):
+    return TypeVar(name, _ConstGenericMarker, constraint)
+
 def round_away_zero(x):
     if x >= 0.0:
         return math.floor(x + 0.5)
@@ -99,6 +105,7 @@ def patch(module):
     module.uint32 = uint32
     module.uint64 = uint64
     module.TypeVar = TypeVar
+    module.ConstGeneric = ConstGeneric
     module.Generic = Generic
     module.extern = extern
     module.Option = Option

nac3standalone/demo/src/const_generic.py

@@ -0,0 +1,50 @@
+A = ConstGeneric("A", int32)
+B = ConstGeneric("B", uint32)
+T = TypeVar("T")
+
+class ConstGenericClass(Generic[A]):
+    def __init__(self):
+        pass
+
+class ConstGeneric2Class(Generic[A, B]):
+    def __init__(self):
+        pass
+
+class HybridGenericClass2(Generic[A, T]):
+    pass
+
+class HybridGenericClass3(Generic[T, A, B]):
+    pass
+
+def make_generic_2() -> ConstGenericClass[2]:
+    return ...
+
+def make_generic2_1_2() -> ConstGeneric2Class[1, 2]:
+    return ...
+
+def make_hybrid_class_2_int32() -> HybridGenericClass2[2, int32]:
+    return ...
+
+def make_hybrid_class_i32_0_1() -> HybridGenericClass3[int32, 0, 1]:
+    return ...
+
+def consume_generic_2(instance: ConstGenericClass[2]):
+    pass
+
+def consume_generic2_1_2(instance: ConstGeneric2Class[1, 2]):
+    pass
+
+def consume_hybrid_class_2_i32(instance: HybridGenericClass2[2, int32]):
+    pass
+
+def consume_hybrid_class_i32_0_1(instance: HybridGenericClass3[int32, 0, 1]):
+    pass
+
+def f():
+    consume_generic_2(make_generic_2())
+    consume_generic2_1_2(make_generic2_1_2())
+    consume_hybrid_class_2_i32(make_hybrid_class_2_int32())
+    consume_hybrid_class_i32_0_1(make_hybrid_class_i32_0_1())
+
+def run() -> int32:
+    return 0

nac3standalone/src/main.rs

@@ -25,7 +25,7 @@ use nac3core::{
     },
 };
 use nac3parser::{
-    ast::{Expr, ExprKind, StmtKind},
+    ast::{Constant, Expr, ExprKind, StmtKind, StrRef},
     parser,
 };
 
@@ -83,6 +83,11 @@ fn handle_typevar_definition(
 
     match &func.node {
         ExprKind::Name { id, .. } if id == &"TypeVar".into() => {
+            let ExprKind::Constant { value: Constant::Str(ty_name), .. } = &args[0].node else {
+                return Err(format!("Expected string constant for first parameter of `TypeVar`, got {:?}", &args[0].node))
+            };
+            let generic_name: StrRef = ty_name.to_string().into();
+
             let constraints = args
                 .iter()
                 .skip(1)
@@ -94,13 +99,50 @@ fn handle_typevar_definition(
                         primitives,
                         x,
                         Default::default(),
+                        None,
                     )?;
                     get_type_from_type_annotation_kinds(
                         def_list, unifier, primitives, &ty, &mut None
                     )
                 })
                 .collect::<Result<Vec<_>, _>>()?;
-            Ok(unifier.get_fresh_var_with_range(&constraints, None, None).0)
+            let loc = func.location;
+
+            if constraints.len() == 1 {
+                return Err(format!("A single constraint is not allowed (at {})", loc))
+            }
+
+            Ok(unifier.get_fresh_var_with_range(&constraints, Some(generic_name), Some(loc)).0)
+        }
+
+        ExprKind::Name { id, .. } if id == &"ConstGeneric".into() => {
+            if args.len() != 2 {
+                return Err(format!("Expected 2 arguments for `ConstGeneric`, got {}", args.len()))
+            }
+
+            let ExprKind::Constant { value: Constant::Str(ty_name), .. } = &args[0].node else {
+                return Err(format!(
+                    "Expected string constant for first parameter of `ConstGeneric`, got {:?}",
+                    &args[0].node
+                ))
+            };
+            let generic_name: StrRef = ty_name.to_string().into();
+
+            let ty = parse_ast_to_type_annotation_kinds(
+                resolver,
+                def_list,
+                unifier,
+                primitives,
+                &args[1],
+                Default::default(),
+                None,
+            )?;
+            let constraint = get_type_from_type_annotation_kinds(
+                def_list, unifier, primitives, &ty, &mut None
+            )?;
+            let loc = func.location;
+
+            Ok(unifier.get_fresh_const_generic_var(constraint, Some(generic_name), Some(loc)).0)
         }
 
         _ => Err(format!(