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Diffstat (limited to 'vendor/syn/src/generics.rs')
| -rw-r--r-- | vendor/syn/src/generics.rs | 1227 |
1 files changed, 0 insertions, 1227 deletions
diff --git a/vendor/syn/src/generics.rs b/vendor/syn/src/generics.rs deleted file mode 100644 index aed50e3..0000000 --- a/vendor/syn/src/generics.rs +++ /dev/null @@ -1,1227 +0,0 @@ -use super::*; -use crate::punctuated::{Iter, IterMut, Punctuated}; -use proc_macro2::TokenStream; -#[cfg(all(feature = "printing", feature = "extra-traits"))] -use std::fmt::{self, Debug}; -#[cfg(all(feature = "printing", feature = "extra-traits"))] -use std::hash::{Hash, Hasher}; - -ast_struct! { - /// Lifetimes and type parameters attached to a declaration of a function, - /// enum, trait, etc. - /// - /// This struct represents two distinct optional syntactic elements, - /// [generic parameters] and [where clause]. In some locations of the - /// grammar, there may be other tokens in between these two things. - /// - /// [generic parameters]: https://doc.rust-lang.org/stable/reference/items/generics.html#generic-parameters - /// [where clause]: https://doc.rust-lang.org/stable/reference/items/generics.html#where-clauses - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct Generics { - pub lt_token: Option<Token![<]>, - pub params: Punctuated<GenericParam, Token![,]>, - pub gt_token: Option<Token![>]>, - pub where_clause: Option<WhereClause>, - } -} - -ast_enum_of_structs! { - /// A generic type parameter, lifetime, or const generic: `T: Into<String>`, - /// `'a: 'b`, `const LEN: usize`. - /// - /// # Syntax tree enum - /// - /// This type is a [syntax tree enum]. - /// - /// [syntax tree enum]: Expr#syntax-tree-enums - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub enum GenericParam { - /// A lifetime parameter: `'a: 'b + 'c + 'd`. - Lifetime(LifetimeParam), - - /// A generic type parameter: `T: Into<String>`. - Type(TypeParam), - - /// A const generic parameter: `const LENGTH: usize`. - Const(ConstParam), - } -} - -ast_struct! { - /// A lifetime definition: `'a: 'b + 'c + 'd`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct LifetimeParam { - pub attrs: Vec<Attribute>, - pub lifetime: Lifetime, - pub colon_token: Option<Token![:]>, - pub bounds: Punctuated<Lifetime, Token![+]>, - } -} - -ast_struct! { - /// A generic type parameter: `T: Into<String>`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct TypeParam { - pub attrs: Vec<Attribute>, - pub ident: Ident, - pub colon_token: Option<Token![:]>, - pub bounds: Punctuated<TypeParamBound, Token![+]>, - pub eq_token: Option<Token![=]>, - pub default: Option<Type>, - } -} - -ast_struct! { - /// A const generic parameter: `const LENGTH: usize`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct ConstParam { - pub attrs: Vec<Attribute>, - pub const_token: Token![const], - pub ident: Ident, - pub colon_token: Token![:], - pub ty: Type, - pub eq_token: Option<Token![=]>, - pub default: Option<Expr>, - } -} - -impl Default for Generics { - fn default() -> Self { - Generics { - lt_token: None, - params: Punctuated::new(), - gt_token: None, - where_clause: None, - } - } -} - -impl Generics { - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &</code><a - /// href="struct.LifetimeParam.html"><code - /// style="padding-left:0;padding-right:0;">LifetimeParam</code></a><code - /// style="padding-left:0;">></code> - /// over the lifetime parameters in `self.params`. - pub fn lifetimes(&self) -> Lifetimes { - Lifetimes(self.params.iter()) - } - - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &mut </code><a - /// href="struct.LifetimeParam.html"><code - /// style="padding-left:0;padding-right:0;">LifetimeParam</code></a><code - /// style="padding-left:0;">></code> - /// over the lifetime parameters in `self.params`. - pub fn lifetimes_mut(&mut self) -> LifetimesMut { - LifetimesMut(self.params.iter_mut()) - } - - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &</code><a - /// href="struct.TypeParam.html"><code - /// style="padding-left:0;padding-right:0;">TypeParam</code></a><code - /// style="padding-left:0;">></code> - /// over the type parameters in `self.params`. - pub fn type_params(&self) -> TypeParams { - TypeParams(self.params.iter()) - } - - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &mut </code><a - /// href="struct.TypeParam.html"><code - /// style="padding-left:0;padding-right:0;">TypeParam</code></a><code - /// style="padding-left:0;">></code> - /// over the type parameters in `self.params`. - pub fn type_params_mut(&mut self) -> TypeParamsMut { - TypeParamsMut(self.params.iter_mut()) - } - - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &</code><a - /// href="struct.ConstParam.html"><code - /// style="padding-left:0;padding-right:0;">ConstParam</code></a><code - /// style="padding-left:0;">></code> - /// over the constant parameters in `self.params`. - pub fn const_params(&self) -> ConstParams { - ConstParams(self.params.iter()) - } - - /// Returns an - /// <code - /// style="padding-right:0;">Iterator<Item = &mut </code><a - /// href="struct.ConstParam.html"><code - /// style="padding-left:0;padding-right:0;">ConstParam</code></a><code - /// style="padding-left:0;">></code> - /// over the constant parameters in `self.params`. - pub fn const_params_mut(&mut self) -> ConstParamsMut { - ConstParamsMut(self.params.iter_mut()) - } - - /// Initializes an empty `where`-clause if there is not one present already. - pub fn make_where_clause(&mut self) -> &mut WhereClause { - self.where_clause.get_or_insert_with(|| WhereClause { - where_token: <Token![where]>::default(), - predicates: Punctuated::new(), - }) - } -} - -pub struct Lifetimes<'a>(Iter<'a, GenericParam>); - -impl<'a> Iterator for Lifetimes<'a> { - type Item = &'a LifetimeParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Lifetime(lifetime) = next { - Some(lifetime) - } else { - self.next() - } - } -} - -pub struct LifetimesMut<'a>(IterMut<'a, GenericParam>); - -impl<'a> Iterator for LifetimesMut<'a> { - type Item = &'a mut LifetimeParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Lifetime(lifetime) = next { - Some(lifetime) - } else { - self.next() - } - } -} - -pub struct TypeParams<'a>(Iter<'a, GenericParam>); - -impl<'a> Iterator for TypeParams<'a> { - type Item = &'a TypeParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Type(type_param) = next { - Some(type_param) - } else { - self.next() - } - } -} - -pub struct TypeParamsMut<'a>(IterMut<'a, GenericParam>); - -impl<'a> Iterator for TypeParamsMut<'a> { - type Item = &'a mut TypeParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Type(type_param) = next { - Some(type_param) - } else { - self.next() - } - } -} - -pub struct ConstParams<'a>(Iter<'a, GenericParam>); - -impl<'a> Iterator for ConstParams<'a> { - type Item = &'a ConstParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Const(const_param) = next { - Some(const_param) - } else { - self.next() - } - } -} - -pub struct ConstParamsMut<'a>(IterMut<'a, GenericParam>); - -impl<'a> Iterator for ConstParamsMut<'a> { - type Item = &'a mut ConstParam; - - fn next(&mut self) -> Option<Self::Item> { - let next = match self.0.next() { - Some(item) => item, - None => return None, - }; - if let GenericParam::Const(const_param) = next { - Some(const_param) - } else { - self.next() - } - } -} - -/// Returned by `Generics::split_for_impl`. -#[cfg(feature = "printing")] -#[cfg_attr( - doc_cfg, - doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))) -)] -pub struct ImplGenerics<'a>(&'a Generics); - -/// Returned by `Generics::split_for_impl`. -#[cfg(feature = "printing")] -#[cfg_attr( - doc_cfg, - doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))) -)] -pub struct TypeGenerics<'a>(&'a Generics); - -/// Returned by `TypeGenerics::as_turbofish`. -#[cfg(feature = "printing")] -#[cfg_attr( - doc_cfg, - doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))) -)] -pub struct Turbofish<'a>(&'a Generics); - -#[cfg(feature = "printing")] -impl Generics { - /// Split a type's generics into the pieces required for impl'ing a trait - /// for that type. - /// - /// ``` - /// # use proc_macro2::{Span, Ident}; - /// # use quote::quote; - /// # - /// # let generics: syn::Generics = Default::default(); - /// # let name = Ident::new("MyType", Span::call_site()); - /// # - /// let (impl_generics, ty_generics, where_clause) = generics.split_for_impl(); - /// quote! { - /// impl #impl_generics MyTrait for #name #ty_generics #where_clause { - /// // ... - /// } - /// } - /// # ; - /// ``` - #[cfg_attr( - doc_cfg, - doc(cfg(all(any(feature = "full", feature = "derive"), feature = "printing"))) - )] - pub fn split_for_impl(&self) -> (ImplGenerics, TypeGenerics, Option<&WhereClause>) { - ( - ImplGenerics(self), - TypeGenerics(self), - self.where_clause.as_ref(), - ) - } -} - -#[cfg(feature = "printing")] -macro_rules! generics_wrapper_impls { - ($ty:ident) => { - #[cfg(feature = "clone-impls")] - #[cfg_attr(doc_cfg, doc(cfg(feature = "clone-impls")))] - impl<'a> Clone for $ty<'a> { - fn clone(&self) -> Self { - $ty(self.0) - } - } - - #[cfg(feature = "extra-traits")] - #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))] - impl<'a> Debug for $ty<'a> { - fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { - formatter - .debug_tuple(stringify!($ty)) - .field(self.0) - .finish() - } - } - - #[cfg(feature = "extra-traits")] - #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))] - impl<'a> Eq for $ty<'a> {} - - #[cfg(feature = "extra-traits")] - #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))] - impl<'a> PartialEq for $ty<'a> { - fn eq(&self, other: &Self) -> bool { - self.0 == other.0 - } - } - - #[cfg(feature = "extra-traits")] - #[cfg_attr(doc_cfg, doc(cfg(feature = "extra-traits")))] - impl<'a> Hash for $ty<'a> { - fn hash<H: Hasher>(&self, state: &mut H) { - self.0.hash(state); - } - } - }; -} - -#[cfg(feature = "printing")] -generics_wrapper_impls!(ImplGenerics); -#[cfg(feature = "printing")] -generics_wrapper_impls!(TypeGenerics); -#[cfg(feature = "printing")] -generics_wrapper_impls!(Turbofish); - -#[cfg(feature = "printing")] -impl<'a> TypeGenerics<'a> { - /// Turn a type's generics like `<X, Y>` into a turbofish like `::<X, Y>`. - pub fn as_turbofish(&self) -> Turbofish { - Turbofish(self.0) - } -} - -ast_struct! { - /// A set of bound lifetimes: `for<'a, 'b, 'c>`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct BoundLifetimes { - pub for_token: Token![for], - pub lt_token: Token![<], - pub lifetimes: Punctuated<GenericParam, Token![,]>, - pub gt_token: Token![>], - } -} - -impl Default for BoundLifetimes { - fn default() -> Self { - BoundLifetimes { - for_token: Default::default(), - lt_token: Default::default(), - lifetimes: Punctuated::new(), - gt_token: Default::default(), - } - } -} - -impl LifetimeParam { - pub fn new(lifetime: Lifetime) -> Self { - LifetimeParam { - attrs: Vec::new(), - lifetime, - colon_token: None, - bounds: Punctuated::new(), - } - } -} - -impl From<Ident> for TypeParam { - fn from(ident: Ident) -> Self { - TypeParam { - attrs: vec![], - ident, - colon_token: None, - bounds: Punctuated::new(), - eq_token: None, - default: None, - } - } -} - -ast_enum_of_structs! { - /// A trait or lifetime used as a bound on a type parameter. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - #[non_exhaustive] - pub enum TypeParamBound { - Trait(TraitBound), - Lifetime(Lifetime), - Verbatim(TokenStream), - } -} - -ast_struct! { - /// A trait used as a bound on a type parameter. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct TraitBound { - pub paren_token: Option<token::Paren>, - pub modifier: TraitBoundModifier, - /// The `for<'a>` in `for<'a> Foo<&'a T>` - pub lifetimes: Option<BoundLifetimes>, - /// The `Foo<&'a T>` in `for<'a> Foo<&'a T>` - pub path: Path, - } -} - -ast_enum! { - /// A modifier on a trait bound, currently only used for the `?` in - /// `?Sized`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub enum TraitBoundModifier { - None, - Maybe(Token![?]), - } -} - -ast_struct! { - /// A `where` clause in a definition: `where T: Deserialize<'de>, D: - /// 'static`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct WhereClause { - pub where_token: Token![where], - pub predicates: Punctuated<WherePredicate, Token![,]>, - } -} - -ast_enum_of_structs! { - /// A single predicate in a `where` clause: `T: Deserialize<'de>`. - /// - /// # Syntax tree enum - /// - /// This type is a [syntax tree enum]. - /// - /// [syntax tree enum]: Expr#syntax-tree-enums - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - #[non_exhaustive] - pub enum WherePredicate { - /// A lifetime predicate in a `where` clause: `'a: 'b + 'c`. - Lifetime(PredicateLifetime), - - /// A type predicate in a `where` clause: `for<'c> Foo<'c>: Trait<'c>`. - Type(PredicateType), - } -} - -ast_struct! { - /// A lifetime predicate in a `where` clause: `'a: 'b + 'c`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct PredicateLifetime { - pub lifetime: Lifetime, - pub colon_token: Token![:], - pub bounds: Punctuated<Lifetime, Token![+]>, - } -} - -ast_struct! { - /// A type predicate in a `where` clause: `for<'c> Foo<'c>: Trait<'c>`. - #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] - pub struct PredicateType { - /// Any lifetimes from a `for` binding - pub lifetimes: Option<BoundLifetimes>, - /// The type being bounded - pub bounded_ty: Type, - pub colon_token: Token![:], - /// Trait and lifetime bounds (`Clone+Send+'static`) - pub bounds: Punctuated<TypeParamBound, Token![+]>, - } -} - -#[cfg(feature = "parsing")] -pub(crate) mod parsing { - use super::*; - use crate::ext::IdentExt as _; - use crate::parse::{Parse, ParseStream, Result}; - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for Generics { - fn parse(input: ParseStream) -> Result<Self> { - if !input.peek(Token![<]) { - return Ok(Generics::default()); - } - - let lt_token: Token![<] = input.parse()?; - - let mut params = Punctuated::new(); - loop { - if input.peek(Token![>]) { - break; - } - - let attrs = input.call(Attribute::parse_outer)?; - let lookahead = input.lookahead1(); - if lookahead.peek(Lifetime) { - params.push_value(GenericParam::Lifetime(LifetimeParam { - attrs, - ..input.parse()? - })); - } else if lookahead.peek(Ident) { - params.push_value(GenericParam::Type(TypeParam { - attrs, - ..input.parse()? - })); - } else if lookahead.peek(Token![const]) { - params.push_value(GenericParam::Const(ConstParam { - attrs, - ..input.parse()? - })); - } else if input.peek(Token![_]) { - params.push_value(GenericParam::Type(TypeParam { - attrs, - ident: input.call(Ident::parse_any)?, - colon_token: None, - bounds: Punctuated::new(), - eq_token: None, - default: None, - })); - } else { - return Err(lookahead.error()); - } - - if input.peek(Token![>]) { - break; - } - let punct = input.parse()?; - params.push_punct(punct); - } - - let gt_token: Token![>] = input.parse()?; - - Ok(Generics { - lt_token: Some(lt_token), - params, - gt_token: Some(gt_token), - where_clause: None, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for GenericParam { - fn parse(input: ParseStream) -> Result<Self> { - let attrs = input.call(Attribute::parse_outer)?; - - let lookahead = input.lookahead1(); - if lookahead.peek(Ident) { - Ok(GenericParam::Type(TypeParam { - attrs, - ..input.parse()? - })) - } else if lookahead.peek(Lifetime) { - Ok(GenericParam::Lifetime(LifetimeParam { - attrs, - ..input.parse()? - })) - } else if lookahead.peek(Token![const]) { - Ok(GenericParam::Const(ConstParam { - attrs, - ..input.parse()? - })) - } else { - Err(lookahead.error()) - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for LifetimeParam { - fn parse(input: ParseStream) -> Result<Self> { - let has_colon; - Ok(LifetimeParam { - attrs: input.call(Attribute::parse_outer)?, - lifetime: input.parse()?, - colon_token: { - if input.peek(Token![:]) { - has_colon = true; - Some(input.parse()?) - } else { - has_colon = false; - None - } - }, - bounds: { - let mut bounds = Punctuated::new(); - if has_colon { - loop { - if input.peek(Token![,]) || input.peek(Token![>]) { - break; - } - let value = input.parse()?; - bounds.push_value(value); - if !input.peek(Token![+]) { - break; - } - let punct = input.parse()?; - bounds.push_punct(punct); - } - } - bounds - }, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for BoundLifetimes { - fn parse(input: ParseStream) -> Result<Self> { - Ok(BoundLifetimes { - for_token: input.parse()?, - lt_token: input.parse()?, - lifetimes: { - let mut lifetimes = Punctuated::new(); - while !input.peek(Token![>]) { - let attrs = input.call(Attribute::parse_outer)?; - let lifetime: Lifetime = input.parse()?; - lifetimes.push_value(GenericParam::Lifetime(LifetimeParam { - attrs, - lifetime, - colon_token: None, - bounds: Punctuated::new(), - })); - if input.peek(Token![>]) { - break; - } - lifetimes.push_punct(input.parse()?); - } - lifetimes - }, - gt_token: input.parse()?, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for Option<BoundLifetimes> { - fn parse(input: ParseStream) -> Result<Self> { - if input.peek(Token![for]) { - input.parse().map(Some) - } else { - Ok(None) - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for TypeParam { - fn parse(input: ParseStream) -> Result<Self> { - let attrs = input.call(Attribute::parse_outer)?; - let ident: Ident = input.parse()?; - let colon_token: Option<Token![:]> = input.parse()?; - - let mut bounds = Punctuated::new(); - if colon_token.is_some() { - loop { - if input.peek(Token![,]) || input.peek(Token![>]) || input.peek(Token![=]) { - break; - } - let value: TypeParamBound = input.parse()?; - bounds.push_value(value); - if !input.peek(Token![+]) { - break; - } - let punct: Token![+] = input.parse()?; - bounds.push_punct(punct); - } - } - - let eq_token: Option<Token![=]> = input.parse()?; - let default = if eq_token.is_some() { - Some(input.parse::<Type>()?) - } else { - None - }; - - Ok(TypeParam { - attrs, - ident, - colon_token, - bounds, - eq_token, - default, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for TypeParamBound { - fn parse(input: ParseStream) -> Result<Self> { - if input.peek(Lifetime) { - return input.parse().map(TypeParamBound::Lifetime); - } - - let begin = input.fork(); - - let content; - let (paren_token, content) = if input.peek(token::Paren) { - (Some(parenthesized!(content in input)), &content) - } else { - (None, input) - }; - - let is_tilde_const = - cfg!(feature = "full") && content.peek(Token![~]) && content.peek2(Token![const]); - if is_tilde_const { - content.parse::<Token![~]>()?; - content.parse::<Token![const]>()?; - } - - let mut bound: TraitBound = content.parse()?; - bound.paren_token = paren_token; - - if is_tilde_const { - Ok(TypeParamBound::Verbatim(verbatim::between(&begin, input))) - } else { - Ok(TypeParamBound::Trait(bound)) - } - } - } - - impl TypeParamBound { - pub(crate) fn parse_multiple( - input: ParseStream, - allow_plus: bool, - ) -> Result<Punctuated<Self, Token![+]>> { - let mut bounds = Punctuated::new(); - loop { - bounds.push_value(input.parse()?); - if !(allow_plus && input.peek(Token![+])) { - break; - } - bounds.push_punct(input.parse()?); - if !(input.peek(Ident::peek_any) - || input.peek(Token![::]) - || input.peek(Token![?]) - || input.peek(Lifetime) - || input.peek(token::Paren) - || input.peek(Token![~])) - { - break; - } - } - Ok(bounds) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for TraitBound { - fn parse(input: ParseStream) -> Result<Self> { - let modifier: TraitBoundModifier = input.parse()?; - let lifetimes: Option<BoundLifetimes> = input.parse()?; - - let mut path: Path = input.parse()?; - if path.segments.last().unwrap().arguments.is_empty() - && (input.peek(token::Paren) || input.peek(Token![::]) && input.peek3(token::Paren)) - { - input.parse::<Option<Token![::]>>()?; - let args: ParenthesizedGenericArguments = input.parse()?; - let parenthesized = PathArguments::Parenthesized(args); - path.segments.last_mut().unwrap().arguments = parenthesized; - } - - Ok(TraitBound { - paren_token: None, - modifier, - lifetimes, - path, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for TraitBoundModifier { - fn parse(input: ParseStream) -> Result<Self> { - if input.peek(Token![?]) { - input.parse().map(TraitBoundModifier::Maybe) - } else { - Ok(TraitBoundModifier::None) - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for ConstParam { - fn parse(input: ParseStream) -> Result<Self> { - let mut default = None; - Ok(ConstParam { - attrs: input.call(Attribute::parse_outer)?, - const_token: input.parse()?, - ident: input.parse()?, - colon_token: input.parse()?, - ty: input.parse()?, - eq_token: { - if input.peek(Token![=]) { - let eq_token = input.parse()?; - default = Some(path::parsing::const_argument(input)?); - Some(eq_token) - } else { - None - } - }, - default, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for WhereClause { - fn parse(input: ParseStream) -> Result<Self> { - Ok(WhereClause { - where_token: input.parse()?, - predicates: { - let mut predicates = Punctuated::new(); - loop { - if input.is_empty() - || input.peek(token::Brace) - || input.peek(Token![,]) - || input.peek(Token![;]) - || input.peek(Token![:]) && !input.peek(Token![::]) - || input.peek(Token![=]) - { - break; - } - let value = input.parse()?; - predicates.push_value(value); - if !input.peek(Token![,]) { - break; - } - let punct = input.parse()?; - predicates.push_punct(punct); - } - predicates - }, - }) - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for Option<WhereClause> { - fn parse(input: ParseStream) -> Result<Self> { - if input.peek(Token![where]) { - input.parse().map(Some) - } else { - Ok(None) - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] - impl Parse for WherePredicate { - fn parse(input: ParseStream) -> Result<Self> { - if input.peek(Lifetime) && input.peek2(Token![:]) { - Ok(WherePredicate::Lifetime(PredicateLifetime { - lifetime: input.parse()?, - colon_token: input.parse()?, - bounds: { - let mut bounds = Punctuated::new(); - loop { - if input.is_empty() - || input.peek(token::Brace) - || input.peek(Token![,]) - || input.peek(Token![;]) - || input.peek(Token![:]) - || input.peek(Token![=]) - { - break; - } - let value = input.parse()?; - bounds.push_value(value); - if !input.peek(Token![+]) { - break; - } - let punct = input.parse()?; - bounds.push_punct(punct); - } - bounds - }, - })) - } else { - Ok(WherePredicate::Type(PredicateType { - lifetimes: input.parse()?, - bounded_ty: input.parse()?, - colon_token: input.parse()?, - bounds: { - let mut bounds = Punctuated::new(); - loop { - if input.is_empty() - || input.peek(token::Brace) - || input.peek(Token![,]) - || input.peek(Token![;]) - || input.peek(Token![:]) && !input.peek(Token![::]) - || input.peek(Token![=]) - { - break; - } - let value = input.parse()?; - bounds.push_value(value); - if !input.peek(Token![+]) { - break; - } - let punct = input.parse()?; - bounds.push_punct(punct); - } - bounds - }, - })) - } - } - } -} - -#[cfg(feature = "printing")] -mod printing { - use super::*; - use crate::attr::FilterAttrs; - use crate::print::TokensOrDefault; - use proc_macro2::TokenStream; - use quote::{ToTokens, TokenStreamExt}; - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for Generics { - fn to_tokens(&self, tokens: &mut TokenStream) { - if self.params.is_empty() { - return; - } - - TokensOrDefault(&self.lt_token).to_tokens(tokens); - - // Print lifetimes before types and consts, regardless of their - // order in self.params. - let mut trailing_or_empty = true; - for param in self.params.pairs() { - if let GenericParam::Lifetime(_) = **param.value() { - param.to_tokens(tokens); - trailing_or_empty = param.punct().is_some(); - } - } - for param in self.params.pairs() { - match param.value() { - GenericParam::Type(_) | GenericParam::Const(_) => { - if !trailing_or_empty { - <Token![,]>::default().to_tokens(tokens); - trailing_or_empty = true; - } - param.to_tokens(tokens); - } - GenericParam::Lifetime(_) => {} - } - } - - TokensOrDefault(&self.gt_token).to_tokens(tokens); - } - } - - impl<'a> ToTokens for ImplGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - if self.0.params.is_empty() { - return; - } - - TokensOrDefault(&self.0.lt_token).to_tokens(tokens); - - // Print lifetimes before types and consts, regardless of their - // order in self.params. - let mut trailing_or_empty = true; - for param in self.0.params.pairs() { - if let GenericParam::Lifetime(_) = **param.value() { - param.to_tokens(tokens); - trailing_or_empty = param.punct().is_some(); - } - } - for param in self.0.params.pairs() { - if let GenericParam::Lifetime(_) = **param.value() { - continue; - } - if !trailing_or_empty { - <Token![,]>::default().to_tokens(tokens); - trailing_or_empty = true; - } - match param.value() { - GenericParam::Lifetime(_) => unreachable!(), - GenericParam::Type(param) => { - // Leave off the type parameter defaults - tokens.append_all(param.attrs.outer()); - param.ident.to_tokens(tokens); - if !param.bounds.is_empty() { - TokensOrDefault(¶m.colon_token).to_tokens(tokens); - param.bounds.to_tokens(tokens); - } - } - GenericParam::Const(param) => { - // Leave off the const parameter defaults - tokens.append_all(param.attrs.outer()); - param.const_token.to_tokens(tokens); - param.ident.to_tokens(tokens); - param.colon_token.to_tokens(tokens); - param.ty.to_tokens(tokens); - } - } - param.punct().to_tokens(tokens); - } - - TokensOrDefault(&self.0.gt_token).to_tokens(tokens); - } - } - - impl<'a> ToTokens for TypeGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - if self.0.params.is_empty() { - return; - } - - TokensOrDefault(&self.0.lt_token).to_tokens(tokens); - - // Print lifetimes before types and consts, regardless of their - // order in self.params. - let mut trailing_or_empty = true; - for param in self.0.params.pairs() { - if let GenericParam::Lifetime(def) = *param.value() { - // Leave off the lifetime bounds and attributes - def.lifetime.to_tokens(tokens); - param.punct().to_tokens(tokens); - trailing_or_empty = param.punct().is_some(); - } - } - for param in self.0.params.pairs() { - if let GenericParam::Lifetime(_) = **param.value() { - continue; - } - if !trailing_or_empty { - <Token![,]>::default().to_tokens(tokens); - trailing_or_empty = true; - } - match param.value() { - GenericParam::Lifetime(_) => unreachable!(), - GenericParam::Type(param) => { - // Leave off the type parameter defaults - param.ident.to_tokens(tokens); - } - GenericParam::Const(param) => { - // Leave off the const parameter defaults - param.ident.to_tokens(tokens); - } - } - param.punct().to_tokens(tokens); - } - - TokensOrDefault(&self.0.gt_token).to_tokens(tokens); - } - } - - impl<'a> ToTokens for Turbofish<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - if !self.0.params.is_empty() { - <Token![::]>::default().to_tokens(tokens); - TypeGenerics(self.0).to_tokens(tokens); - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for BoundLifetimes { - fn to_tokens(&self, tokens: &mut TokenStream) { - self.for_token.to_tokens(tokens); - self.lt_token.to_tokens(tokens); - self.lifetimes.to_tokens(tokens); - self.gt_token.to_tokens(tokens); - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for LifetimeParam { - fn to_tokens(&self, tokens: &mut TokenStream) { - tokens.append_all(self.attrs.outer()); - self.lifetime.to_tokens(tokens); - if !self.bounds.is_empty() { - TokensOrDefault(&self.colon_token).to_tokens(tokens); - self.bounds.to_tokens(tokens); - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for TypeParam { - fn to_tokens(&self, tokens: &mut TokenStream) { - tokens.append_all(self.attrs.outer()); - self.ident.to_tokens(tokens); - if !self.bounds.is_empty() { - TokensOrDefault(&self.colon_token).to_tokens(tokens); - self.bounds.to_tokens(tokens); - } - if let Some(default) = &self.default { - TokensOrDefault(&self.eq_token).to_tokens(tokens); - default.to_tokens(tokens); - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for TraitBound { - fn to_tokens(&self, tokens: &mut TokenStream) { - let to_tokens = |tokens: &mut TokenStream| { - self.modifier.to_tokens(tokens); - self.lifetimes.to_tokens(tokens); - self.path.to_tokens(tokens); - }; - match &self.paren_token { - Some(paren) => paren.surround(tokens, to_tokens), - None => to_tokens(tokens), - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for TraitBoundModifier { - fn to_tokens(&self, tokens: &mut TokenStream) { - match self { - TraitBoundModifier::None => {} - TraitBoundModifier::Maybe(t) => t.to_tokens(tokens), - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for ConstParam { - fn to_tokens(&self, tokens: &mut TokenStream) { - tokens.append_all(self.attrs.outer()); - self.const_token.to_tokens(tokens); - self.ident.to_tokens(tokens); - self.colon_token.to_tokens(tokens); - self.ty.to_tokens(tokens); - if let Some(default) = &self.default { - TokensOrDefault(&self.eq_token).to_tokens(tokens); - default.to_tokens(tokens); - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for WhereClause { - fn to_tokens(&self, tokens: &mut TokenStream) { - if !self.predicates.is_empty() { - self.where_token.to_tokens(tokens); - self.predicates.to_tokens(tokens); - } - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for PredicateLifetime { - fn to_tokens(&self, tokens: &mut TokenStream) { - self.lifetime.to_tokens(tokens); - self.colon_token.to_tokens(tokens); - self.bounds.to_tokens(tokens); - } - } - - #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] - impl ToTokens for PredicateType { - fn to_tokens(&self, tokens: &mut TokenStream) { - self.lifetimes.to_tokens(tokens); - self.bounded_ty.to_tokens(tokens); - self.colon_token.to_tokens(tokens); - self.bounds.to_tokens(tokens); - } - } -} |