feat(frontend)!: Explicit numeric generics and type kinds

aztec_macros/src/transforms/storage.rs

@@ -91,7 +91,7 @@
             r#struct.attributes.iter().any(|attr| is_custom_attribute(attr, "aztec(storage)"))
         })
         .unwrap();
-    storage_struct.generics.push(ident("Context"));
+    storage_struct.generics.push(ident("Context").into());
     storage_struct
         .fields
         .iter_mut()
@@ -173,7 +173,7 @@
 ///
 /// To:
 ///
 /// impl<Context> Storage<Contex> {
 ///    fn init(context: Context) -> Self {
 ///        Storage {
 ///             a_map: Map::new(context, 0, |context, slot| {
@@ -243,7 +243,7 @@
             span: Some(Span::default()),
         },
         type_span: Span::default(),
-        generics: vec![generic_context_ident],
+        generics: vec![generic_context_ident.into()],
 
         methods: vec![(init, Span::default())],
     };

compiler/noirc_frontend/src/ast/expression.rs

@@ -38,7 +38,28 @@ pub enum ExpressionKind {
 
 /// A Vec of unresolved names for type variables.
 /// For `fn foo<A, B>(...)` this corresponds to vec!["A", "B"].
-pub type UnresolvedGenerics = Vec<Ident>;
+pub type UnresolvedGenerics = Vec<UnresolvedGeneric>;
+
+#[derive(Debug, PartialEq, Eq, Clone, Hash)]
+pub enum UnresolvedGeneric {
+    Variable(Ident),
+    Numeric { ident: Ident, typ: UnresolvedType },
+}
+
+impl Display for UnresolvedGeneric {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            UnresolvedGeneric::Variable(ident) => write!(f, "{ident}"),
+            UnresolvedGeneric::Numeric { ident, typ } => write!(f, "let {ident}: {typ}"),
+        }
+    }
+}
+
+impl From<Ident> for UnresolvedGeneric {
+    fn from(value: Ident) -> Self {
+        UnresolvedGeneric::Variable(value)
+    }
+}
 
 impl ExpressionKind {
     pub fn into_path(self) -> Option<Path> {

compiler/noirc_frontend/src/ast/mod.rs

@@ -116,7 +116,7 @@
         /*env:*/ Box<UnresolvedType>,
     ),
 
     // The type of quoted code for metaprogramming
     Code,
 
     Unspecified, // This is for when the user declares a variable without specifying it's type
@@ -138,7 +138,7 @@
     (Ident, Option<(Option<Vec<UnresolvedType>>, Vec<Expression>)>);
 
 /// The precursor to TypeExpression, this is the type that the parser allows
-/// to be used in the length position of an array type. Only constants, variables,
+/// to be used in the length position of an array type. Only constant integers, variables,
 /// and numeric binary operators are allowed here.
 #[derive(Debug, PartialEq, Eq, Clone, Hash)]
 pub enum UnresolvedTypeExpression {

compiler/noirc_frontend/src/ast/statement.rs

@@ -8,7 +8,7 @@ use noirc_errors::{Span, Spanned};
 
 use super::{
     BlockExpression, Expression, ExpressionKind, IndexExpression, MemberAccessExpression,
-    MethodCallExpression, UnresolvedType,
+    MethodCallExpression, UnresolvedGeneric, UnresolvedType,
 };
 use crate::lexer::token::SpannedToken;
 use crate::macros_api::SecondaryAttribute;
@@ -225,6 +225,24 @@ impl From<SpannedToken> for Ident {
     }
 }
 
+impl From<UnresolvedGeneric> for Ident {
+    fn from(value: UnresolvedGeneric) -> Self {
+        match value {
+            UnresolvedGeneric::Variable(ident) | UnresolvedGeneric::Numeric { ident, .. } => ident,
+        }
+    }
+}
+
+impl From<&UnresolvedGeneric> for Ident {
+    fn from(value: &UnresolvedGeneric) -> Self {
+        match value {
+            UnresolvedGeneric::Variable(ident) | UnresolvedGeneric::Numeric { ident, .. } => {
+                ident.clone()
+            }
+        }
+    }
+}
+
 impl From<Ident> for Expression {
     fn from(i: Ident) -> Expression {
         Expression {

compiler/noirc_frontend/src/ast/structure.rs

@@ -20,7 +20,7 @@ impl NoirStruct {
     pub fn new(
         name: Ident,
         attributes: Vec<SecondaryAttribute>,
-        generics: Vec<Ident>,
+        generics: UnresolvedGenerics,
         fields: Vec<(Ident, UnresolvedType)>,
         span: Span,
     ) -> NoirStruct {

compiler/noirc_frontend/src/ast/traits.rs

@@ -14,7 +14,7 @@ use crate::node_interner::TraitId;
 #[derive(Clone, Debug)]
 pub struct NoirTrait {
     pub name: Ident,
-    pub generics: Vec<Ident>,
+    pub generics: UnresolvedGenerics,
     pub where_clause: Vec<UnresolvedTraitConstraint>,
     pub span: Span,
     pub items: Vec<TraitItem>,
@@ -26,7 +26,7 @@ pub struct NoirTrait {
 pub enum TraitItem {
     Function {
         name: Ident,
-        generics: Vec<Ident>,
+        generics: UnresolvedGenerics,
         parameters: Vec<(Ident, UnresolvedType)>,
         return_type: FunctionReturnType,
         where_clause: Vec<UnresolvedTraitConstraint>,