Add initial grammar for impl blocks and optimize grammar [3]

src/ast/common.rs

@@ -23,12 +23,27 @@ pub struct DocString {
     contents: String,
 }
 
+/// Identifiers, without a path or generics.
 #[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct Ident {
     pub name: String,
     pub span: Span,
 }
 
+/// A type name, supporting fully qualified paths and generics:
+/// ```
+/// std::module::X<T>
+/// ```
+/// Used only when specifying types.
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
+pub struct TypeName {
+    pub path: Vec<Ident>,
+    pub name: Ident,
+    pub generics: Vec<TypeName>,
+    pub span: Span,
+}
+
+/// Used as a generic param in function and struct declarations.
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct GenericParam {
     pub name: Ident,

src/ast/functions.rs

@@ -29,3 +29,10 @@ pub struct Param {
     pub name: Ident,
     pub r#type: TypeDescriptor,
 }
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ImplBlock {
+    pub target: Ident,
+    pub methods: Vec<FunctionDef>,
+    pub span: Span,
+}

src/ast/modules.rs

@@ -2,7 +2,7 @@ use super::{
     common::{DocString, Ident, Span},
     constants::ConstantDef,
     enums::{EnumDecl, UnionDecl},
-    functions::{FunctionDecl, FunctionDef},
+    functions::{FunctionDecl, FunctionDef, ImplBlock},
     imports::ImportStmt,
     structs::StructDecl,
     types::TypeDecl,
@@ -23,6 +23,7 @@ pub enum ModuleDefItem {
     Constant(ConstantDef),
     Function(FunctionDef),
     FunctionDecl(FunctionDecl),
+    Impl(ImplBlock),
     Struct(StructDecl),
     Union(UnionDecl),
     Enum(EnumDecl),

src/ast/types.rs

@@ -1,10 +1,9 @@
-use super::common::{DocString, Ident, Span};
+use super::common::{DocString, Ident, Span, TypeName};
 
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub enum TypeDescriptor {
     Type {
-        name: Ident,
-        generics: Vec<Self>,
+        name: TypeName,
         span: Span,
     },
     Ref {