refactor(ast_tools): shorten code by hoisting imports (#6903)

Pure refactor.

tasks/ast_tools/src/derives/mod.rs

@@ -1,7 +1,9 @@
 use convert_case::{Case, Casing};
 use itertools::Itertools;
 use proc_macro2::TokenStream;
+use quote::quote;
 use rustc_hash::{FxHashMap, FxHashSet};
+use syn::{parse_str, ItemUse};
 
 use crate::{
     codegen::LateCtx,
@@ -49,15 +51,14 @@ pub trait Derive {
                 .chain(it.strip_suffix("::mod").unwrap_or(it).split("::").skip(1))
                 .chain(["*"])
                 .join("::");
-            let use_module: syn::ItemUse =
-                syn::parse_str(format!("use {local_path};").as_str()).unwrap();
-            quote::quote! {
+            let use_module: ItemUse = parse_str(format!("use {local_path};").as_str()).unwrap();
+            quote! {
                 ///@@line_break
                 #use_module
             }
         });
 
-        quote::quote! {
+        quote! {
             #prelude
 
             #(#use_modules)*
@@ -103,7 +104,7 @@ pub trait Derive {
                     tokens: Self::template(
                         modules,
                         streams.into_iter().fold(TokenStream::new(), |mut acc, it| {
-                            acc.extend(quote::quote! {
+                            acc.extend(quote! {
                                 ///@@line_break
                             });
                             acc.extend(it);

tasks/ast_tools/src/markers.rs

@@ -5,7 +5,7 @@ use syn::{
     parenthesized,
     parse::{Parse, ParseStream},
     parse2,
-    punctuated::Punctuated,
+    punctuated::{self, Punctuated},
     spanned::Spanned,
     token, Attribute, Expr, Ident, LitStr, Meta, MetaNameValue, Token,
 };
@@ -38,7 +38,7 @@ impl Parse for VisitArg {
 pub struct VisitArgs(Punctuated<VisitArg, Token![,]>);
 
 impl IntoIterator for VisitArgs {
-    type IntoIter = syn::punctuated::IntoIter<Self::Item>;
+    type IntoIter = punctuated::IntoIter<Self::Item>;
     type Item = VisitArg;
 
     fn into_iter(self) -> Self::IntoIter {

tasks/ast_tools/src/output/rust.rs

@@ -28,7 +28,7 @@ fn generate_header(generator_path: &str) -> TokenStream {
 
     // TODO: Add generation date, AST source hash, etc here.
     let edit_comment = format!("@ To edit this generated file you have to edit `{generator_path}`");
-    quote::quote! {
+    quote! {
         //!@ Auto-generated code, DO NOT EDIT DIRECTLY!
         #![doc = #edit_comment]
         //!@@line_break

tasks/ast_tools/src/schema/defs.rs

@@ -1,4 +1,5 @@
 use serde::Serialize;
+use syn::Ident;
 
 use super::{with_either, TypeName};
 use crate::{
@@ -120,7 +121,7 @@ pub struct VariantDef {
 }
 
 impl VariantDef {
-    pub fn ident(&self) -> syn::Ident {
+    pub fn ident(&self) -> Ident {
         self.name.to_ident()
     }
 
@@ -176,7 +177,7 @@ impl From<&syn::Visibility> for Visibility {
 }
 
 impl FieldDef {
-    pub fn ident(&self) -> Option<syn::Ident> {
+    pub fn ident(&self) -> Option<Ident> {
         self.name.as_ref().map(ToIdent::to_ident)
     }
 }

tasks/ast_tools/src/schema/get_generics.rs

@@ -1,4 +1,4 @@
-use syn::parse_quote;
+use syn::{parse_quote, Generics};
 
 use super::{
     defs::{EnumDef, StructDef, TypeDef},
@@ -10,7 +10,7 @@ pub trait GetGenerics {
         false
     }
 
-    fn generics(&self) -> Option<syn::Generics> {
+    fn generics(&self) -> Option<Generics> {
         if self.has_lifetime() {
             Some(parse_quote!(<'a>))
         } else {

tasks/ast_tools/src/schema/get_ident.rs

@@ -1,3 +1,5 @@
+use syn::Ident;
+
 use super::{
     defs::{EnumDef, StructDef, TypeDef},
     with_either,
@@ -5,23 +7,23 @@ use super::{
 use crate::util::ToIdent;
 
 pub trait GetIdent {
-    fn ident(&self) -> syn::Ident;
+    fn ident(&self) -> Ident;
 }
 
 impl GetIdent for TypeDef {
-    fn ident(&self) -> syn::Ident {
+    fn ident(&self) -> Ident {
         with_either!(self, it => it.ident())
     }
 }
 
 impl GetIdent for StructDef {
-    fn ident(&self) -> syn::Ident {
+    fn ident(&self) -> Ident {
         self.name.to_ident()
     }
 }
 
 impl GetIdent for EnumDef {
-    fn ident(&self) -> syn::Ident {
+    fn ident(&self) -> Ident {
         self.name.to_ident()
     }
 }

tasks/ast_tools/src/schema/mod.rs

@@ -3,9 +3,13 @@ use std::fmt;
 use quote::ToTokens;
 use rustc_hash::FxHashSet;
 use serde::Serialize;
+use syn::{
+    punctuated::Punctuated, Attribute, Expr, ExprLit, Field, Ident, Lit, Meta, MetaNameValue,
+    Token, Type, Variant,
+};
 
 use crate::{
-    codegen,
+    codegen::EarlyCtx,
     layout::KnownLayout,
     markers::{
         get_derive_attributes, get_estree_attribute, get_scope_attribute, get_scope_markers,
@@ -121,18 +125,18 @@ impl<'a> IntoIterator for &'a Schema {
     }
 }
 
-fn parse_struct_outer_markers(attrs: &Vec<syn::Attribute>) -> Result<StructOuterMarkers> {
+fn parse_struct_outer_markers(attrs: &Vec<Attribute>) -> Result<StructOuterMarkers> {
     Ok(StructOuterMarkers {
         scope: get_scope_attribute(attrs).transpose()?,
         estree: get_estree_attribute(attrs).transpose()?,
     })
 }
 
-fn parse_enum_outer_markers(attrs: &Vec<syn::Attribute>) -> Result<EnumOuterMarkers> {
+fn parse_enum_outer_markers(attrs: &Vec<Attribute>) -> Result<EnumOuterMarkers> {
     Ok(EnumOuterMarkers { estree: get_estree_attribute(attrs).transpose()?.unwrap_or_default() })
 }
 
-fn parse_inner_markers(attrs: &Vec<syn::Attribute>) -> Result<InnerMarkers> {
+fn parse_inner_markers(attrs: &Vec<Attribute>) -> Result<InnerMarkers> {
     Ok(InnerMarkers {
         span: attrs.iter().any(|a| a.path().is_ident("span")),
         visit: get_visit_markers(attrs)?,
@@ -142,7 +146,7 @@ fn parse_inner_markers(attrs: &Vec<syn::Attribute>) -> Result<InnerMarkers> {
 }
 
 // lower `AstType` to `TypeDef`.
-pub fn lower_ast_types(ctx: &codegen::EarlyCtx) -> Schema {
+pub fn lower_ast_types(ctx: &EarlyCtx) -> Schema {
     let defs = ctx
         .mods()
         .borrow()
@@ -153,7 +157,7 @@ pub fn lower_ast_types(ctx: &codegen::EarlyCtx) -> Schema {
     Schema { defs }
 }
 
-fn lower_ast_type(ty: &rust::AstType, ctx: &codegen::EarlyCtx) -> TypeDef {
+fn lower_ast_type(ty: &rust::AstType, ctx: &EarlyCtx) -> TypeDef {
     match ty {
         rust::AstType::Enum(it) => TypeDef::Enum(lower_ast_enum(it, ctx)),
         rust::AstType::Struct(it) => TypeDef::Struct(lower_ast_struct(it, ctx)),
@@ -161,7 +165,7 @@ fn lower_ast_type(ty: &rust::AstType, ctx: &codegen::EarlyCtx) -> TypeDef {
     }
 }
 
-fn lower_ast_enum(it @ rust::Enum { item, meta }: &rust::Enum, ctx: &codegen::EarlyCtx) -> EnumDef {
+fn lower_ast_enum(it @ rust::Enum { item, meta }: &rust::Enum, ctx: &EarlyCtx) -> EnumDef {
     let (size_64, align_64, offsets_64) = meta
         .layout_64
         .clone()
@@ -199,10 +203,7 @@ fn lower_ast_enum(it @ rust::Enum { item, meta }: &rust::Enum, ctx: &codegen::Ea
     }
 }
 
-fn lower_ast_struct(
-    it @ rust::Struct { item, meta }: &rust::Struct,
-    ctx: &codegen::EarlyCtx,
-) -> StructDef {
+fn lower_ast_struct(it @ rust::Struct { item, meta }: &rust::Struct, ctx: &EarlyCtx) -> StructDef {
     let (size_64, align_64, offsets_64) = meta
         .layout_64
         .clone()
@@ -234,7 +235,7 @@ fn lower_ast_struct(
     }
 }
 
-fn lower_variant<F>(variant: &syn::Variant, enum_dbg_name: F, ctx: &codegen::EarlyCtx) -> VariantDef
+fn lower_variant<F>(variant: &Variant, enum_dbg_name: F, ctx: &EarlyCtx) -> VariantDef
 where
     F: Fn() -> String,
 {
@@ -243,7 +244,7 @@ where
         discriminant: variant.discriminant.as_ref().map_or_else(
             || panic!("expected explicit enum discriminants on {}", enum_dbg_name()),
             |(_, disc)| match disc {
-                syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Int(lit), .. }) => {
+                Expr::Lit(ExprLit { lit: Lit::Int(lit), .. }) => {
                     lit.base10_parse().expect("invalid base10 enum discriminant")
                 }
                 _ => panic!("invalid enum discriminant {:?} on {}", disc, enum_dbg_name()),
@@ -254,7 +255,7 @@ where
     }
 }
 
-fn lower_inherit(inherit: &rust::Inherit, ctx: &codegen::EarlyCtx) -> InheritDef {
+fn lower_inherit(inherit: &rust::Inherit, ctx: &EarlyCtx) -> InheritDef {
     match inherit {
         rust::Inherit::Linked { super_, variants } => InheritDef {
             super_: create_type_ref(super_, ctx),
@@ -269,7 +270,7 @@ fn lower_inherit(inherit: &rust::Inherit, ctx: &codegen::EarlyCtx) -> InheritDef
     }
 }
 
-fn lower_field(field: &syn::Field, ctx: &codegen::EarlyCtx) -> FieldDef {
+fn lower_field(field: &Field, ctx: &EarlyCtx) -> FieldDef {
     FieldDef {
         name: field
             .ident
@@ -282,7 +283,7 @@ fn lower_field(field: &syn::Field, ctx: &codegen::EarlyCtx) -> FieldDef {
     }
 }
 
-fn create_type_ref(ty: &syn::Type, ctx: &codegen::EarlyCtx) -> TypeRef {
+fn create_type_ref(ty: &Type, ctx: &EarlyCtx) -> TypeRef {
     let ident = ty.get_ident();
     let id = ident.as_ident().and_then(|id| ctx.type_id(&id.to_string()));
     let transparent_id = ctx.type_id(&ident.inner_ident().to_string());
@@ -296,21 +297,16 @@ fn create_type_ref(ty: &syn::Type, ctx: &codegen::EarlyCtx) -> TypeRef {
     }
 }
 
-fn get_docs(attrs: &[syn::Attribute]) -> Vec<String> {
+fn get_docs(attrs: &[Attribute]) -> Vec<String> {
     attrs
         .iter()
         .filter_map(|attr| {
-            if let syn::Meta::NameValue(syn::MetaNameValue {
-                path,
-                value: syn::Expr::Lit(lit),
-                ..
-            }) = &attr.meta
-            {
+            if let Meta::NameValue(MetaNameValue { path, value: Expr::Lit(lit), .. }) = &attr.meta {
                 if !path.is_ident("doc") {
                     return None;
                 }
                 match &lit.lit {
-                    syn::Lit::Str(lit) => Some(lit.value().trim().to_string()),
+                    Lit::Str(lit) => Some(lit.value().trim().to_string()),
                     _ => None,
                 }
             } else {
@@ -320,15 +316,15 @@ fn get_docs(attrs: &[syn::Attribute]) -> Vec<String> {
         .collect()
 }
 
-fn parse_generate_derive(attrs: &[syn::Attribute]) -> Vec<String> {
+fn parse_generate_derive(attrs: &[Attribute]) -> Vec<String> {
     let mut derives = FxHashSet::default();
     for attr in attrs {
         if !attr.path().is_ident("generate_derive") {
             continue;
         }
 
-        let args: syn::punctuated::Punctuated<syn::Ident, syn::Token![,]> =
-            attr.parse_args_with(syn::punctuated::Punctuated::parse_terminated).unwrap();
+        let args: Punctuated<Ident, Token![,]> =
+            attr.parse_args_with(Punctuated::parse_terminated).unwrap();
 
         for arg in args {
             derives.insert(arg.to_string());

tasks/ast_tools/src/schema/to_type.rs

@@ -1,6 +1,6 @@
 use proc_macro2::TokenStream;
 use quote::ToTokens;
-use syn::parse_quote;
+use syn::{parse_quote, parse_str, Type};
 
 use super::{
     defs::{EnumDef, StructDef, TypeDef, TypeRef},
@@ -8,21 +8,21 @@ use super::{
 };
 
 pub trait ToType {
-    fn to_type(&self) -> syn::Type;
-    fn to_type_elide(&self) -> syn::Type;
-    fn to_type_with_explicit_generics(&self, generics: TokenStream) -> syn::Type;
+    fn to_type(&self) -> Type;
+    fn to_type_elide(&self) -> Type;
+    fn to_type_with_explicit_generics(&self, generics: TokenStream) -> Type;
 }
 
 impl ToType for TypeRef {
-    fn to_type(&self) -> syn::Type {
-        syn::parse_str(self.raw()).unwrap()
+    fn to_type(&self) -> Type {
+        parse_str(self.raw()).unwrap()
     }
 
-    fn to_type_elide(&self) -> syn::Type {
+    fn to_type_elide(&self) -> Type {
         self.to_type_with_explicit_generics(proc_macro2::TokenStream::default())
     }
 
-    fn to_type_with_explicit_generics(&self, generics: proc_macro2::TokenStream) -> syn::Type {
+    fn to_type_with_explicit_generics(&self, generics: proc_macro2::TokenStream) -> Type {
         let ident = self.name().first_ident();
         parse_quote!(#ident #generics)
     }
@@ -38,15 +38,15 @@ macro_rules! auto_impl_to_type {
     ($($ty:ty,)+) => (
         $(
             impl ToType for $ty {
-                fn to_type(&self) -> syn::Type {
+                fn to_type(&self) -> Type {
                     self.to_type_with_explicit_generics(self.generics().to_token_stream())
                 }
 
-                fn to_type_elide(&self) -> syn::Type {
+                fn to_type_elide(&self) -> Type {
                     self.to_type_with_explicit_generics(TokenStream::default())
                 }
 
-                fn to_type_with_explicit_generics(&self, generics: TokenStream) -> syn::Type {
+                fn to_type_with_explicit_generics(&self, generics: TokenStream) -> Type {
                     let name = self.ident();
                     parse_quote!(#name #generics)
                 }