use super::*;
use crate::derive::{Data, DataEnum, DataStruct, DataUnion, DeriveInput};
use crate::punctuated::Punctuated;
use proc_macro2::TokenStream;
#[cfg(feature = "extra-traits")]
use crate::tt::TokenStreamHelper;
#[cfg(feature = "extra-traits")]
use std::hash::{Hash, Hasher};
#[cfg(feature = "parsing")]
use std::mem;
ast_enum_of_structs! {
/// Things that can appear directly inside of a module or scope.
///
/// *This type is available if Syn is built with the `"full"` feature.*
///
/// # Syntax tree enum
///
/// This type is a [syntax tree enum].
///
/// [syntax tree enum]: enum.Expr.html#syntax-tree-enums
//
// TODO: change syntax-tree-enum link to an intra rustdoc link, currently
// blocked on https://github.com/rust-lang/rust/issues/62833
pub enum Item #manual_extra_traits {
/// A constant item: `const MAX: u16 = 65535`.
Const(ItemConst),
/// An enum definition: `enum Foo { A(A), B(B) }`.
Enum(ItemEnum),
/// An `extern crate` item: `extern crate serde`.
ExternCrate(ItemExternCrate),
/// A free-standing function: `fn process(n: usize) -> Result<()> { ...
/// }`.
Fn(ItemFn),
/// A block of foreign items: `extern "C" { ... }`.
ForeignMod(ItemForeignMod),
/// An impl block providing trait or associated items: `impl Trait
/// for Data { ... }`.
Impl(ItemImpl),
/// A macro invocation, which includes `macro_rules!` definitions.
Macro(ItemMacro),
/// A 2.0-style declarative macro introduced by the `macro` keyword.
Macro2(ItemMacro2),
/// A module or module declaration: `mod m` or `mod m { ... }`.
Mod(ItemMod),
/// A static item: `static BIKE: Shed = Shed(42)`.
Static(ItemStatic),
/// A struct definition: `struct Foo { x: A }`.
Struct(ItemStruct),
/// A trait definition: `pub trait Iterator { ... }`.
Trait(ItemTrait),
/// A trait alias: `pub trait SharableIterator = Iterator + Sync`.
TraitAlias(ItemTraitAlias),
/// A type alias: `type Result = std::result::Result`.
Type(ItemType),
/// A union definition: `union Foo { x: A, y: B }`.
Union(ItemUnion),
/// A use declaration: `use std::collections::HashMap`.
Use(ItemUse),
/// Tokens forming an item not interpreted by Syn.
Verbatim(TokenStream),
#[doc(hidden)]
__Nonexhaustive,
}
}
ast_struct! {
/// A constant item: `const MAX: u16 = 65535`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemConst {
pub attrs: Vec,
pub vis: Visibility,
pub const_token: Token![const],
pub ident: Ident,
pub colon_token: Token![:],
pub ty: Box,
pub eq_token: Token![=],
pub expr: Box,
pub semi_token: Token![;],
}
}
ast_struct! {
/// An enum definition: `enum Foo { A(A), B(B) }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemEnum {
pub attrs: Vec,
pub vis: Visibility,
pub enum_token: Token![enum],
pub ident: Ident,
pub generics: Generics,
pub brace_token: token::Brace,
pub variants: Punctuated,
}
}
ast_struct! {
/// An `extern crate` item: `extern crate serde`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemExternCrate {
pub attrs: Vec,
pub vis: Visibility,
pub extern_token: Token![extern],
pub crate_token: Token![crate],
pub ident: Ident,
pub rename: Option<(Token![as], Ident)>,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A free-standing function: `fn process(n: usize) -> Result<()> { ...
/// }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemFn {
pub attrs: Vec,
pub vis: Visibility,
pub sig: Signature,
pub block: Box,
}
}
ast_struct! {
/// A block of foreign items: `extern "C" { ... }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemForeignMod {
pub attrs: Vec,
pub abi: Abi,
pub brace_token: token::Brace,
pub items: Vec,
}
}
ast_struct! {
/// An impl block providing trait or associated items: `impl Trait
/// for Data { ... }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemImpl {
pub attrs: Vec,
pub defaultness: Option,
pub unsafety: Option,
pub impl_token: Token![impl],
pub generics: Generics,
/// Trait this impl implements.
pub trait_: Option<(Option, Path, Token![for])>,
/// The Self type of the impl.
pub self_ty: Box,
pub brace_token: token::Brace,
pub items: Vec,
}
}
ast_struct! {
/// A macro invocation, which includes `macro_rules!` definitions.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemMacro {
pub attrs: Vec,
/// The `example` in `macro_rules! example { ... }`.
pub ident: Option,
pub mac: Macro,
pub semi_token: Option,
}
}
ast_struct! {
/// A 2.0-style declarative macro introduced by the `macro` keyword.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemMacro2 #manual_extra_traits {
pub attrs: Vec,
pub vis: Visibility,
pub macro_token: Token![macro],
pub ident: Ident,
pub rules: TokenStream,
}
}
ast_struct! {
/// A module or module declaration: `mod m` or `mod m { ... }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemMod {
pub attrs: Vec,
pub vis: Visibility,
pub mod_token: Token![mod],
pub ident: Ident,
pub content: Option<(token::Brace, Vec- )>,
pub semi: Option,
}
}
ast_struct! {
/// A static item: `static BIKE: Shed = Shed(42)`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemStatic {
pub attrs: Vec,
pub vis: Visibility,
pub static_token: Token![static],
pub mutability: Option,
pub ident: Ident,
pub colon_token: Token![:],
pub ty: Box,
pub eq_token: Token![=],
pub expr: Box,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A struct definition: `struct Foo { x: A }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemStruct {
pub attrs: Vec,
pub vis: Visibility,
pub struct_token: Token![struct],
pub ident: Ident,
pub generics: Generics,
pub fields: Fields,
pub semi_token: Option,
}
}
ast_struct! {
/// A trait definition: `pub trait Iterator { ... }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemTrait {
pub attrs: Vec,
pub vis: Visibility,
pub unsafety: Option,
pub auto_token: Option,
pub trait_token: Token![trait],
pub ident: Ident,
pub generics: Generics,
pub colon_token: Option,
pub supertraits: Punctuated,
pub brace_token: token::Brace,
pub items: Vec,
}
}
ast_struct! {
/// A trait alias: `pub trait SharableIterator = Iterator + Sync`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemTraitAlias {
pub attrs: Vec,
pub vis: Visibility,
pub trait_token: Token![trait],
pub ident: Ident,
pub generics: Generics,
pub eq_token: Token![=],
pub bounds: Punctuated,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A type alias: `type Result = std::result::Result`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemType {
pub attrs: Vec,
pub vis: Visibility,
pub type_token: Token![type],
pub ident: Ident,
pub generics: Generics,
pub eq_token: Token![=],
pub ty: Box,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A union definition: `union Foo { x: A, y: B }`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemUnion {
pub attrs: Vec,
pub vis: Visibility,
pub union_token: Token![union],
pub ident: Ident,
pub generics: Generics,
pub fields: FieldsNamed,
}
}
ast_struct! {
/// A use declaration: `use std::collections::HashMap`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ItemUse {
pub attrs: Vec,
pub vis: Visibility,
pub use_token: Token![use],
pub leading_colon: Option,
pub tree: UseTree,
pub semi_token: Token![;],
}
}
#[cfg(feature = "extra-traits")]
impl Eq for Item {}
#[cfg(feature = "extra-traits")]
impl PartialEq for Item {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(Item::Const(this), Item::Const(other)) => this == other,
(Item::Enum(this), Item::Enum(other)) => this == other,
(Item::ExternCrate(this), Item::ExternCrate(other)) => this == other,
(Item::Fn(this), Item::Fn(other)) => this == other,
(Item::ForeignMod(this), Item::ForeignMod(other)) => this == other,
(Item::Impl(this), Item::Impl(other)) => this == other,
(Item::Macro(this), Item::Macro(other)) => this == other,
(Item::Macro2(this), Item::Macro2(other)) => this == other,
(Item::Mod(this), Item::Mod(other)) => this == other,
(Item::Static(this), Item::Static(other)) => this == other,
(Item::Struct(this), Item::Struct(other)) => this == other,
(Item::Trait(this), Item::Trait(other)) => this == other,
(Item::TraitAlias(this), Item::TraitAlias(other)) => this == other,
(Item::Type(this), Item::Type(other)) => this == other,
(Item::Union(this), Item::Union(other)) => this == other,
(Item::Use(this), Item::Use(other)) => this == other,
(Item::Verbatim(this), Item::Verbatim(other)) => {
TokenStreamHelper(this) == TokenStreamHelper(other)
}
_ => false,
}
}
}
#[cfg(feature = "extra-traits")]
impl Hash for Item {
fn hash(&self, state: &mut H)
where
H: Hasher,
{
match self {
Item::Const(item) => {
state.write_u8(0);
item.hash(state);
}
Item::Enum(item) => {
state.write_u8(1);
item.hash(state);
}
Item::ExternCrate(item) => {
state.write_u8(2);
item.hash(state);
}
Item::Fn(item) => {
state.write_u8(3);
item.hash(state);
}
Item::ForeignMod(item) => {
state.write_u8(4);
item.hash(state);
}
Item::Impl(item) => {
state.write_u8(5);
item.hash(state);
}
Item::Macro(item) => {
state.write_u8(6);
item.hash(state);
}
Item::Macro2(item) => {
state.write_u8(7);
item.hash(state);
}
Item::Mod(item) => {
state.write_u8(8);
item.hash(state);
}
Item::Static(item) => {
state.write_u8(9);
item.hash(state);
}
Item::Struct(item) => {
state.write_u8(10);
item.hash(state);
}
Item::Trait(item) => {
state.write_u8(11);
item.hash(state);
}
Item::TraitAlias(item) => {
state.write_u8(12);
item.hash(state);
}
Item::Type(item) => {
state.write_u8(13);
item.hash(state);
}
Item::Union(item) => {
state.write_u8(14);
item.hash(state);
}
Item::Use(item) => {
state.write_u8(15);
item.hash(state);
}
Item::Verbatim(item) => {
state.write_u8(16);
TokenStreamHelper(item).hash(state);
}
Item::__Nonexhaustive => unreachable!(),
}
}
}
impl Item {
#[cfg(feature = "parsing")]
pub(crate) fn replace_attrs(&mut self, new: Vec) -> Vec {
match self {
Item::ExternCrate(ItemExternCrate { attrs, .. })
| Item::Use(ItemUse { attrs, .. })
| Item::Static(ItemStatic { attrs, .. })
| Item::Const(ItemConst { attrs, .. })
| Item::Fn(ItemFn { attrs, .. })
| Item::Mod(ItemMod { attrs, .. })
| Item::ForeignMod(ItemForeignMod { attrs, .. })
| Item::Type(ItemType { attrs, .. })
| Item::Struct(ItemStruct { attrs, .. })
| Item::Enum(ItemEnum { attrs, .. })
| Item::Union(ItemUnion { attrs, .. })
| Item::Trait(ItemTrait { attrs, .. })
| Item::TraitAlias(ItemTraitAlias { attrs, .. })
| Item::Impl(ItemImpl { attrs, .. })
| Item::Macro(ItemMacro { attrs, .. })
| Item::Macro2(ItemMacro2 { attrs, .. }) => mem::replace(attrs, new),
Item::Verbatim(_) => Vec::new(),
Item::__Nonexhaustive => unreachable!(),
}
}
}
#[cfg(feature = "extra-traits")]
impl Eq for ItemMacro2 {}
#[cfg(feature = "extra-traits")]
impl PartialEq for ItemMacro2 {
fn eq(&self, other: &Self) -> bool {
self.attrs == other.attrs
&& self.vis == other.vis
&& self.macro_token == other.macro_token
&& self.ident == other.ident
&& TokenStreamHelper(&self.rules) == TokenStreamHelper(&other.rules)
}
}
#[cfg(feature = "extra-traits")]
impl Hash for ItemMacro2 {
fn hash(&self, state: &mut H)
where
H: Hasher,
{
self.attrs.hash(state);
self.vis.hash(state);
self.macro_token.hash(state);
self.ident.hash(state);
TokenStreamHelper(&self.rules).hash(state);
}
}
impl From for Item {
fn from(input: DeriveInput) -> Item {
match input.data {
Data::Struct(data) => Item::Struct(ItemStruct {
attrs: input.attrs,
vis: input.vis,
struct_token: data.struct_token,
ident: input.ident,
generics: input.generics,
fields: data.fields,
semi_token: data.semi_token,
}),
Data::Enum(data) => Item::Enum(ItemEnum {
attrs: input.attrs,
vis: input.vis,
enum_token: data.enum_token,
ident: input.ident,
generics: input.generics,
brace_token: data.brace_token,
variants: data.variants,
}),
Data::Union(data) => Item::Union(ItemUnion {
attrs: input.attrs,
vis: input.vis,
union_token: data.union_token,
ident: input.ident,
generics: input.generics,
fields: data.fields,
}),
}
}
}
impl From for DeriveInput {
fn from(input: ItemStruct) -> DeriveInput {
DeriveInput {
attrs: input.attrs,
vis: input.vis,
ident: input.ident,
generics: input.generics,
data: Data::Struct(DataStruct {
struct_token: input.struct_token,
fields: input.fields,
semi_token: input.semi_token,
}),
}
}
}
impl From for DeriveInput {
fn from(input: ItemEnum) -> DeriveInput {
DeriveInput {
attrs: input.attrs,
vis: input.vis,
ident: input.ident,
generics: input.generics,
data: Data::Enum(DataEnum {
enum_token: input.enum_token,
brace_token: input.brace_token,
variants: input.variants,
}),
}
}
}
impl From for DeriveInput {
fn from(input: ItemUnion) -> DeriveInput {
DeriveInput {
attrs: input.attrs,
vis: input.vis,
ident: input.ident,
generics: input.generics,
data: Data::Union(DataUnion {
union_token: input.union_token,
fields: input.fields,
}),
}
}
}
ast_enum_of_structs! {
/// A suffix of an import tree in a `use` item: `Type as Renamed` or `*`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
///
/// # Syntax tree enum
///
/// This type is a [syntax tree enum].
///
/// [syntax tree enum]: enum.Expr.html#syntax-tree-enums
//
// TODO: change syntax-tree-enum link to an intra rustdoc link, currently
// blocked on https://github.com/rust-lang/rust/issues/62833
pub enum UseTree {
/// A path prefix of imports in a `use` item: `std::...`.
Path(UsePath),
/// An identifier imported by a `use` item: `HashMap`.
Name(UseName),
/// An renamed identifier imported by a `use` item: `HashMap as Map`.
Rename(UseRename),
/// A glob import in a `use` item: `*`.
Glob(UseGlob),
/// A braced group of imports in a `use` item: `{A, B, C}`.
Group(UseGroup),
}
}
ast_struct! {
/// A path prefix of imports in a `use` item: `std::...`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct UsePath {
pub ident: Ident,
pub colon2_token: Token![::],
pub tree: Box,
}
}
ast_struct! {
/// An identifier imported by a `use` item: `HashMap`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct UseName {
pub ident: Ident,
}
}
ast_struct! {
/// An renamed identifier imported by a `use` item: `HashMap as Map`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct UseRename {
pub ident: Ident,
pub as_token: Token![as],
pub rename: Ident,
}
}
ast_struct! {
/// A glob import in a `use` item: `*`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct UseGlob {
pub star_token: Token![*],
}
}
ast_struct! {
/// A braced group of imports in a `use` item: `{A, B, C}`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct UseGroup {
pub brace_token: token::Brace,
pub items: Punctuated,
}
}
ast_enum_of_structs! {
/// An item within an `extern` block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
///
/// # Syntax tree enum
///
/// This type is a [syntax tree enum].
///
/// [syntax tree enum]: enum.Expr.html#syntax-tree-enums
//
// TODO: change syntax-tree-enum link to an intra rustdoc link, currently
// blocked on https://github.com/rust-lang/rust/issues/62833
pub enum ForeignItem #manual_extra_traits {
/// A foreign function in an `extern` block.
Fn(ForeignItemFn),
/// A foreign static item in an `extern` block: `static ext: u8`.
Static(ForeignItemStatic),
/// A foreign type in an `extern` block: `type void`.
Type(ForeignItemType),
/// A macro invocation within an extern block.
Macro(ForeignItemMacro),
/// Tokens in an `extern` block not interpreted by Syn.
Verbatim(TokenStream),
#[doc(hidden)]
__Nonexhaustive,
}
}
ast_struct! {
/// A foreign function in an `extern` block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ForeignItemFn {
pub attrs: Vec,
pub vis: Visibility,
pub sig: Signature,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A foreign static item in an `extern` block: `static ext: u8`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ForeignItemStatic {
pub attrs: Vec,
pub vis: Visibility,
pub static_token: Token![static],
pub mutability: Option,
pub ident: Ident,
pub colon_token: Token![:],
pub ty: Box,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A foreign type in an `extern` block: `type void`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ForeignItemType {
pub attrs: Vec,
pub vis: Visibility,
pub type_token: Token![type],
pub ident: Ident,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A macro invocation within an extern block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ForeignItemMacro {
pub attrs: Vec,
pub mac: Macro,
pub semi_token: Option,
}
}
#[cfg(feature = "extra-traits")]
impl Eq for ForeignItem {}
#[cfg(feature = "extra-traits")]
impl PartialEq for ForeignItem {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(ForeignItem::Fn(this), ForeignItem::Fn(other)) => this == other,
(ForeignItem::Static(this), ForeignItem::Static(other)) => this == other,
(ForeignItem::Type(this), ForeignItem::Type(other)) => this == other,
(ForeignItem::Macro(this), ForeignItem::Macro(other)) => this == other,
(ForeignItem::Verbatim(this), ForeignItem::Verbatim(other)) => {
TokenStreamHelper(this) == TokenStreamHelper(other)
}
_ => false,
}
}
}
#[cfg(feature = "extra-traits")]
impl Hash for ForeignItem {
fn hash(&self, state: &mut H)
where
H: Hasher,
{
match self {
ForeignItem::Fn(item) => {
state.write_u8(0);
item.hash(state);
}
ForeignItem::Static(item) => {
state.write_u8(1);
item.hash(state);
}
ForeignItem::Type(item) => {
state.write_u8(2);
item.hash(state);
}
ForeignItem::Macro(item) => {
state.write_u8(3);
item.hash(state);
}
ForeignItem::Verbatim(item) => {
state.write_u8(4);
TokenStreamHelper(item).hash(state);
}
ForeignItem::__Nonexhaustive => unreachable!(),
}
}
}
ast_enum_of_structs! {
/// An item declaration within the definition of a trait.
///
/// *This type is available if Syn is built with the `"full"` feature.*
///
/// # Syntax tree enum
///
/// This type is a [syntax tree enum].
///
/// [syntax tree enum]: enum.Expr.html#syntax-tree-enums
//
// TODO: change syntax-tree-enum link to an intra rustdoc link, currently
// blocked on https://github.com/rust-lang/rust/issues/62833
pub enum TraitItem #manual_extra_traits {
/// An associated constant within the definition of a trait.
Const(TraitItemConst),
/// A trait method within the definition of a trait.
Method(TraitItemMethod),
/// An associated type within the definition of a trait.
Type(TraitItemType),
/// A macro invocation within the definition of a trait.
Macro(TraitItemMacro),
/// Tokens within the definition of a trait not interpreted by Syn.
Verbatim(TokenStream),
#[doc(hidden)]
__Nonexhaustive,
}
}
ast_struct! {
/// An associated constant within the definition of a trait.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct TraitItemConst {
pub attrs: Vec,
pub const_token: Token![const],
pub ident: Ident,
pub colon_token: Token![:],
pub ty: Type,
pub default: Option<(Token![=], Expr)>,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A trait method within the definition of a trait.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct TraitItemMethod {
pub attrs: Vec,
pub sig: Signature,
pub default: Option,
pub semi_token: Option,
}
}
ast_struct! {
/// An associated type within the definition of a trait.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct TraitItemType {
pub attrs: Vec,
pub type_token: Token![type],
pub ident: Ident,
pub generics: Generics,
pub colon_token: Option,
pub bounds: Punctuated,
pub default: Option<(Token![=], Type)>,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A macro invocation within the definition of a trait.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct TraitItemMacro {
pub attrs: Vec,
pub mac: Macro,
pub semi_token: Option,
}
}
#[cfg(feature = "extra-traits")]
impl Eq for TraitItem {}
#[cfg(feature = "extra-traits")]
impl PartialEq for TraitItem {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(TraitItem::Const(this), TraitItem::Const(other)) => this == other,
(TraitItem::Method(this), TraitItem::Method(other)) => this == other,
(TraitItem::Type(this), TraitItem::Type(other)) => this == other,
(TraitItem::Macro(this), TraitItem::Macro(other)) => this == other,
(TraitItem::Verbatim(this), TraitItem::Verbatim(other)) => {
TokenStreamHelper(this) == TokenStreamHelper(other)
}
_ => false,
}
}
}
#[cfg(feature = "extra-traits")]
impl Hash for TraitItem {
fn hash(&self, state: &mut H)
where
H: Hasher,
{
match self {
TraitItem::Const(item) => {
state.write_u8(0);
item.hash(state);
}
TraitItem::Method(item) => {
state.write_u8(1);
item.hash(state);
}
TraitItem::Type(item) => {
state.write_u8(2);
item.hash(state);
}
TraitItem::Macro(item) => {
state.write_u8(3);
item.hash(state);
}
TraitItem::Verbatim(item) => {
state.write_u8(4);
TokenStreamHelper(item).hash(state);
}
TraitItem::__Nonexhaustive => unreachable!(),
}
}
}
ast_enum_of_structs! {
/// An item within an impl block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
///
/// # Syntax tree enum
///
/// This type is a [syntax tree enum].
///
/// [syntax tree enum]: enum.Expr.html#syntax-tree-enums
//
// TODO: change syntax-tree-enum link to an intra rustdoc link, currently
// blocked on https://github.com/rust-lang/rust/issues/62833
pub enum ImplItem #manual_extra_traits {
/// An associated constant within an impl block.
Const(ImplItemConst),
/// A method within an impl block.
Method(ImplItemMethod),
/// An associated type within an impl block.
Type(ImplItemType),
/// A macro invocation within an impl block.
Macro(ImplItemMacro),
/// Tokens within an impl block not interpreted by Syn.
Verbatim(TokenStream),
#[doc(hidden)]
__Nonexhaustive,
}
}
ast_struct! {
/// An associated constant within an impl block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ImplItemConst {
pub attrs: Vec,
pub vis: Visibility,
pub defaultness: Option,
pub const_token: Token![const],
pub ident: Ident,
pub colon_token: Token![:],
pub ty: Type,
pub eq_token: Token![=],
pub expr: Expr,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A method within an impl block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ImplItemMethod {
pub attrs: Vec,
pub vis: Visibility,
pub defaultness: Option,
pub sig: Signature,
pub block: Block,
}
}
ast_struct! {
/// An associated type within an impl block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ImplItemType {
pub attrs: Vec,
pub vis: Visibility,
pub defaultness: Option,
pub type_token: Token![type],
pub ident: Ident,
pub generics: Generics,
pub eq_token: Token![=],
pub ty: Type,
pub semi_token: Token![;],
}
}
ast_struct! {
/// A macro invocation within an impl block.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct ImplItemMacro {
pub attrs: Vec,
pub mac: Macro,
pub semi_token: Option,
}
}
#[cfg(feature = "extra-traits")]
impl Eq for ImplItem {}
#[cfg(feature = "extra-traits")]
impl PartialEq for ImplItem {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(ImplItem::Const(this), ImplItem::Const(other)) => this == other,
(ImplItem::Method(this), ImplItem::Method(other)) => this == other,
(ImplItem::Type(this), ImplItem::Type(other)) => this == other,
(ImplItem::Macro(this), ImplItem::Macro(other)) => this == other,
(ImplItem::Verbatim(this), ImplItem::Verbatim(other)) => {
TokenStreamHelper(this) == TokenStreamHelper(other)
}
_ => false,
}
}
}
#[cfg(feature = "extra-traits")]
impl Hash for ImplItem {
fn hash(&self, state: &mut H)
where
H: Hasher,
{
match self {
ImplItem::Const(item) => {
state.write_u8(0);
item.hash(state);
}
ImplItem::Method(item) => {
state.write_u8(1);
item.hash(state);
}
ImplItem::Type(item) => {
state.write_u8(2);
item.hash(state);
}
ImplItem::Macro(item) => {
state.write_u8(3);
item.hash(state);
}
ImplItem::Verbatim(item) => {
state.write_u8(4);
TokenStreamHelper(item).hash(state);
}
ImplItem::__Nonexhaustive => unreachable!(),
}
}
}
ast_struct! {
/// A function signature in a trait or implementation: `unsafe fn
/// initialize(&self)`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct Signature {
pub constness: Option,
pub asyncness: Option,
pub unsafety: Option,
pub abi: Option,
pub fn_token: Token![fn],
pub ident: Ident,
pub generics: Generics,
pub paren_token: token::Paren,
pub inputs: Punctuated,
pub variadic: Option,
pub output: ReturnType,
}
}
impl Signature {
/// A method's `self` receiver, such as `&self` or `self: Box`.
pub fn receiver(&self) -> Option<&FnArg> {
let arg = self.inputs.first()?;
match arg {
FnArg::Receiver(_) => Some(arg),
FnArg::Typed(PatType { pat, .. }) => {
if let Pat::Ident(PatIdent { ident, .. }) = &**pat {
if ident == "self" {
return Some(arg);
}
}
None
}
}
}
}
ast_enum_of_structs! {
/// An argument in a function signature: the `n: usize` in `fn f(n: usize)`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub enum FnArg {
/// The `self` argument of an associated method, whether taken by value
/// or by reference.
///
/// Note that `self` receivers with a specified type, such as `self:
/// Box`, are parsed as a `FnArg::Typed`.
Receiver(Receiver),
/// A function argument accepted by pattern and type.
Typed(PatType),
}
}
ast_struct! {
/// The `self` argument of an associated method, whether taken by value
/// or by reference.
///
/// Note that `self` receivers with a specified type, such as `self:
/// Box`, are parsed as a `FnArg::Typed`.
///
/// *This type is available if Syn is built with the `"full"` feature.*
pub struct Receiver {
pub attrs: Vec,
pub reference: Option<(Token![&], Option)>,
pub mutability: Option,
pub self_token: Token![self],
}
}
impl Receiver {
pub fn lifetime(&self) -> Option<&Lifetime> {
self.reference.as_ref()?.1.as_ref()
}
}
#[cfg(feature = "parsing")]
pub mod parsing {
use super::*;
use crate::ext::IdentExt;
use crate::parse::discouraged::Speculative;
use crate::parse::{Parse, ParseStream, Result};
use crate::token::Brace;
use proc_macro2::{Delimiter, Group, Punct, Spacing, TokenTree};
use std::iter::{self, FromIterator};
crate::custom_keyword!(existential);
impl Parse for Item {
fn parse(input: ParseStream) -> Result {
let mut attrs = input.call(Attribute::parse_outer)?;
let ahead = input.fork();
let vis: Visibility = ahead.parse()?;
let lookahead = ahead.lookahead1();
let mut item = if lookahead.peek(Token![extern]) {
ahead.parse::()?;
let lookahead = ahead.lookahead1();
if lookahead.peek(Token![crate]) {
input.parse().map(Item::ExternCrate)
} else if lookahead.peek(Token![fn]) {
input.parse().map(Item::Fn)
} else if lookahead.peek(token::Brace) {
input.parse().map(Item::ForeignMod)
} else if lookahead.peek(LitStr) {
ahead.parse::()?;
let lookahead = ahead.lookahead1();
if lookahead.peek(token::Brace) {
input.parse().map(Item::ForeignMod)
} else if lookahead.peek(Token![fn]) {
input.parse().map(Item::Fn)
} else {
Err(lookahead.error())
}
} else {
Err(lookahead.error())
}
} else if lookahead.peek(Token![use]) {
input.parse().map(Item::Use)
} else if lookahead.peek(Token![static]) {
input.parse().map(Item::Static)
} else if lookahead.peek(Token![const]) {
ahead.parse::()?;
let lookahead = ahead.lookahead1();
if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
input.parse().map(Item::Const)
} else if lookahead.peek(Token![unsafe])
|| lookahead.peek(Token![async])
|| lookahead.peek(Token![extern])
|| lookahead.peek(Token![fn])
{
input.parse().map(Item::Fn)
} else {
Err(lookahead.error())
}
} else if lookahead.peek(Token![unsafe]) {
ahead.parse::()?;
let lookahead = ahead.lookahead1();
if lookahead.peek(Token![trait])
|| lookahead.peek(Token![auto]) && ahead.peek2(Token![trait])
{
input.parse().map(Item::Trait)
} else if lookahead.peek(Token![impl]) {
input.parse().map(Item::Impl)
} else if lookahead.peek(Token![async])
|| lookahead.peek(Token![extern])
|| lookahead.peek(Token![fn])
{
input.parse().map(Item::Fn)
} else {
Err(lookahead.error())
}
} else if lookahead.peek(Token![async]) || lookahead.peek(Token![fn]) {
input.parse().map(Item::Fn)
} else if lookahead.peek(Token![mod]) {
input.parse().map(Item::Mod)
} else if lookahead.peek(Token![type]) {
input.parse().map(Item::Type)
} else if lookahead.peek(existential) {
input.call(item_existential).map(Item::Verbatim)
} else if lookahead.peek(Token![struct]) {
input.parse().map(Item::Struct)
} else if lookahead.peek(Token![enum]) {
input.parse().map(Item::Enum)
} else if lookahead.peek(Token![union]) && ahead.peek2(Ident) {
input.parse().map(Item::Union)
} else if lookahead.peek(Token![trait]) {
input.call(parse_trait_or_trait_alias)
} else if lookahead.peek(Token![auto]) && ahead.peek2(Token![trait]) {
input.parse().map(Item::Trait)
} else if lookahead.peek(Token![impl])
|| lookahead.peek(Token![default]) && !ahead.peek2(Token![!])
{
input.parse().map(Item::Impl)
} else if lookahead.peek(Token![macro]) {
input.parse().map(Item::Macro2)
} else if vis.is_inherited()
&& (lookahead.peek(Ident)
|| lookahead.peek(Token![self])
|| lookahead.peek(Token![super])
|| lookahead.peek(Token![extern])
|| lookahead.peek(Token![crate])
|| lookahead.peek(Token![::]))
{
input.parse().map(Item::Macro)
} else {
Err(lookahead.error())
}?;
attrs.extend(item.replace_attrs(Vec::new()));
item.replace_attrs(attrs);
Ok(item)
}
}
impl Parse for ItemMacro {
fn parse(input: ParseStream) -> Result {
let attrs = input.call(Attribute::parse_outer)?;
let path = input.call(Path::parse_mod_style)?;
let bang_token: Token![!] = input.parse()?;
let ident: Option = input.parse()?;
let (delimiter, tokens) = input.call(mac::parse_delimiter)?;
let semi_token: Option = if !delimiter.is_brace() {
Some(input.parse()?)
} else {
None
};
Ok(ItemMacro {
attrs,
ident,
mac: Macro {
path,
bang_token,
delimiter,
tokens,
},
semi_token,
})
}
}
impl Parse for ItemMacro2 {
fn parse(input: ParseStream) -> Result {
let attrs = input.call(Attribute::parse_outer)?;
let vis: Visibility = input.parse()?;
let macro_token: Token![macro] = input.parse()?;
let ident: Ident = input.parse()?;
let mut rules = TokenStream::new();
let mut lookahead = input.lookahead1();
if lookahead.peek(token::Paren) {
let paren_content;
let paren_token = parenthesized!(paren_content in input);
let args: TokenStream = paren_content.parse()?;
let mut args = Group::new(Delimiter::Parenthesis, args);
args.set_span(paren_token.span);
rules.extend(iter::once(TokenTree::Group(args)));
lookahead = input.lookahead1();
}
if lookahead.peek(token::Brace) {
let brace_content;
let brace_token = braced!(brace_content in input);
let body: TokenStream = brace_content.parse()?;
let mut body = Group::new(Delimiter::Brace, body);
body.set_span(brace_token.span);
rules.extend(iter::once(TokenTree::Group(body)));
} else {
return Err(lookahead.error());
}
Ok(ItemMacro2 {
attrs,
vis,
macro_token,
ident,
rules,
})
}
}
impl Parse for ItemExternCrate {
fn parse(input: ParseStream) -> Result {
Ok(ItemExternCrate {
attrs: input.call(Attribute::parse_outer)?,
vis: input.parse()?,
extern_token: input.parse()?,
crate_token: input.parse()?,
ident: {
if input.peek(Token![self]) {
input.call(Ident::parse_any)?
} else {
input.parse()?
}
},
rename: {
if input.peek(Token![as]) {
let as_token: Token![as] = input.parse()?;
let rename: Ident = if input.peek(Token![_]) {
Ident::from(input.parse::()?)
} else {
input.parse()?
};
Some((as_token, rename))
} else {
None
}
},
semi_token: input.parse()?,
})
}
}
impl Parse for ItemUse {
fn parse(input: ParseStream) -> Result {
Ok(ItemUse {
attrs: input.call(Attribute::parse_outer)?,
vis: input.parse()?,
use_token: input.parse()?,
leading_colon: input.parse()?,
tree: input.parse()?,
semi_token: input.parse()?,
})
}
}
impl Parse for UseTree {
fn parse(input: ParseStream) -> Result {
let lookahead = input.lookahead1();
if lookahead.peek(Ident)
|| lookahead.peek(Token![self])
|| lookahead.peek(Token![super])
|| lookahead.peek(Token![crate])
|| lookahead.peek(Token![extern])
{
let ident = input.call(Ident::parse_any)?;
if input.peek(Token![::]) {
Ok(UseTree::Path(UsePath {
ident,
colon2_token: input.parse()?,
tree: Box::new(input.parse()?),
}))
} else if input.peek(Token![as]) {
Ok(UseTree::Rename(UseRename {
ident,
as_token: input.parse()?,
rename: {
if input.peek(Ident) {
input.parse()?
} else if input.peek(Token![_]) {
Ident::from(input.parse::()?)
} else {
return Err(input.error("expected identifier or underscore"));
}
},
}))
} else {
Ok(UseTree::Name(UseName { ident }))
}
} else if lookahead.peek(Token![*]) {
Ok(UseTree::Glob(UseGlob {
star_token: input.parse()?,
}))
} else if lookahead.peek(token::Brace) {
let content;
Ok(UseTree::Group(UseGroup {
brace_token: braced!(content in input),
items: content.parse_terminated(UseTree::parse)?,
}))
} else {
Err(lookahead.error())
}
}
}
impl Parse for ItemStatic {
fn parse(input: ParseStream) -> Result {
Ok(ItemStatic {
attrs: input.call(Attribute::parse_outer)?,
vis: input.parse()?,
static_token: input.parse()?,
mutability: input.parse()?,
ident: input.parse()?,
colon_token: input.parse()?,
ty: input.parse()?,
eq_token: input.parse()?,
expr: input.parse()?,
semi_token: input.parse()?,
})
}
}
impl Parse for ItemConst {
fn parse(input: ParseStream) -> Result {
Ok(ItemConst {
attrs: input.call(Attribute::parse_outer)?,
vis: input.parse()?,
const_token: input.parse()?,
ident: {
let lookahead = input.lookahead1();
if lookahead.peek(Ident) || lookahead.peek(Token![_]) {
input.call(Ident::parse_any)?
} else {
return Err(lookahead.error());
}
},
colon_token: input.parse()?,
ty: input.parse()?,
eq_token: input.parse()?,
expr: input.parse()?,
semi_token: input.parse()?,
})
}
}
impl Parse for ItemFn {
fn parse(input: ParseStream) -> Result {
let outer_attrs = input.call(Attribute::parse_outer)?;
let vis: Visibility = input.parse()?;
let constness: Option = input.parse()?;
let asyncness: Option = input.parse()?;
let unsafety: Option = input.parse()?;
let abi: Option = input.parse()?;
let fn_token: Token![fn] = input.parse()?;
let ident: Ident = input.parse()?;
let generics: Generics = input.parse()?;
let content;
let paren_token = parenthesized!(content in input);
let inputs = parse_fn_args(&content)?;
let variadic = inputs.last().as_ref().and_then(get_variadic);
fn get_variadic(input: &&FnArg) -> Option {
if let FnArg::Typed(PatType { ty, .. }) = input {
if let Type::Verbatim(tokens) = &**ty {
if let Ok(dots) = parse2(tokens.clone()) {
return Some(Variadic {
attrs: Vec::new(),
dots,
});
}
}
}
None
}
let output: ReturnType = input.parse()?;
let where_clause: Option = input.parse()?;
let content;
let brace_token = braced!(content in input);
let inner_attrs = content.call(Attribute::parse_inner)?;
let stmts = content.call(Block::parse_within)?;
Ok(ItemFn {
attrs: private::attrs(outer_attrs, inner_attrs),
vis,
sig: Signature {
constness,
asyncness,
unsafety,
abi,
fn_token,
ident,
paren_token,
inputs,
output,
variadic,
generics: Generics {
where_clause,
..generics
},
},
block: Box::new(Block { brace_token, stmts }),
})
}
}
impl Parse for FnArg {
fn parse(input: ParseStream) -> Result {
let attrs = input.call(Attribute::parse_outer)?;
let ahead = input.fork();
if let Ok(mut receiver) = ahead.parse::() {
if !ahead.peek(Token![:]) {
input.advance_to(&ahead);
receiver.attrs = attrs;
return Ok(FnArg::Receiver(receiver));
}
}
let mut typed = input.call(fn_arg_typed)?;
typed.attrs = attrs;
Ok(FnArg::Typed(typed))
}
}
impl Parse for Receiver {
fn parse(input: ParseStream) -> Result {
Ok(Receiver {
attrs: Vec::new(),
reference: {
if input.peek(Token![&]) {
Some((input.parse()?, input.parse()?))
} else {
None
}
},
mutability: input.parse()?,
self_token: input.parse()?,
})
}
}
fn parse_fn_args(input: ParseStream) -> Result> {
let mut args = Punctuated::new();
let mut has_receiver = false;
loop {
if input.is_empty() {
break;
}
let arg: FnArg = input.parse()?;
if let FnArg::Receiver(receiver) = &arg {
if has_receiver {
return Err(Error::new(
receiver.self_token.span,
"unexpected second method receiver",
));
} else if !args.is_empty() {
return Err(Error::new(
receiver.self_token.span,
"unexpected method receiver",
));
}
has_receiver = true;
}
args.push_value(arg);
if input.is_empty() {
break;
}
let comma: Token![,] = input.parse()?;
args.push_punct(comma);
}
Ok(args)
}
fn fn_arg_typed(input: ParseStream) -> Result {
// Hack to parse pre-2018 syntax in
// test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs
// because the rest of the test case is valuable.
if input.peek(Ident) && input.peek2(Token![<]) {
let span = input.fork().parse::()?.span();
return Ok(PatType {
attrs: Vec::new(),
pat: Box::new(Pat::Wild(PatWild {
attrs: Vec::new(),
underscore_token: Token![_](span),
})),
colon_token: Token![:](span),
ty: input.parse()?,
});
}
Ok(PatType {
attrs: Vec::new(),
pat: input.parse()?,
colon_token: input.parse()?,
ty: Box::new(match input.parse::