item::parse
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..52eff8e
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,509 @@
+#[macro_use]
+extern crate nom;
+
+use nom::IResult;
+use nom::multispace as space;
+
+use std::str;
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Item {
+ pub ident: Ident,
+ pub vis: Visibility,
+ pub attrs: Vec<Attribute>,
+ pub generics: Generics,
+ pub body: Body,
+}
+
+pub type Ident = String;
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Attribute {
+ pub value: MetaItem,
+ pub is_sugared_doc: bool,
+}
+
+/// A compile-time attribute item.
+///
+/// E.g. `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum MetaItem {
+ /// Word meta item.
+ ///
+ /// E.g. `test` as in `#[test]`
+ Word(Ident),
+ /// List meta item.
+ ///
+ /// E.g. `derive(..)` as in `#[derive(..)]`
+ List(Ident, Vec<MetaItem>),
+ /// Name value meta item.
+ ///
+ /// E.g. `feature = "foo"` as in `#[feature = "foo"]`
+ NameValue(Ident, String),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq, Default)]
+pub struct Generics {
+ pub lifetimes: Vec<LifetimeDef>,
+ pub ty_params: Vec<TyParam>,
+ pub where_clause: Vec<WherePredicate>,
+}
+
+/// A single predicate in a `where` clause
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum WherePredicate {
+ /// A type binding, e.g. `for<'c> Foo: Send+Clone+'c`
+ BoundPredicate(WhereBoundPredicate),
+ /// A lifetime predicate, e.g. `'a: 'b+'c`
+ RegionPredicate(WhereRegionPredicate),
+}
+
+/// A type bound.
+///
+/// E.g. `for<'c> Foo: Send+Clone+'c`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct WhereBoundPredicate {
+ /// Any lifetimes from a `for` binding
+ pub bound_lifetimes: Vec<LifetimeDef>,
+ /// The type being bounded
+ pub bounded_ty: Ty,
+ /// Trait and lifetime bounds (`Clone+Send+'static`)
+ pub bounds: Vec<TyParamBound>,
+}
+
+/// A lifetime predicate.
+///
+/// E.g. `'a: 'b+'c`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct WhereRegionPredicate {
+ pub lifetime: Lifetime,
+ pub bounds: Vec<Lifetime>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct LifetimeDef {
+ pub lifetime: Lifetime,
+ pub bounds: Vec<Lifetime>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Lifetime {
+ pub ident: Ident,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct TyParam {
+ pub ident: Ident,
+ pub bounds: Vec<TyParamBound>,
+ pub default: Option<Ty>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum TyParamBound {
+ MaybeSized,
+ Region(Lifetime),
+ Trait(PolyTraitRef),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct PolyTraitRef {
+ /// The `'a` in `<'a> Foo<&'a T>`
+ pub bound_lifetimes: Vec<LifetimeDef>,
+ /// The `Foo<&'a T>` in `<'a> Foo<&'a T>`
+ pub trait_ref: Path,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Path {
+ pub global: bool,
+ pub segments: Vec<PathSegment>,
+}
+
+/// A segment of a path: an identifier, an optional lifetime, and a set of types.
+///
+/// E.g. `std`, `String` or `Box<T>`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct PathSegment {
+ pub ident: Ident,
+ pub parameters: PathParameters,
+}
+
+impl PathSegment {
+ pub fn ident(ident: Ident) -> Self {
+ PathSegment {
+ ident: ident,
+ parameters: PathParameters::none(),
+ }
+ }
+}
+
+/// Parameters of a path segment.
+///
+/// E.g. `<A, B>` as in `Foo<A, B>` or `(A, B)` as in `Foo(A, B)`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum PathParameters {
+ /// The `<'a, A, B, C>` in `foo::bar::baz::<'a, A, B, C>`
+ AngleBracketed(AngleBracketedParameterData),
+ /// The `(A, B)` and `C` in `Foo(A, B) -> C`
+ Parenthesized(ParenthesizedParameterData),
+}
+
+impl PathParameters {
+ pub fn none() -> Self {
+ PathParameters::AngleBracketed(AngleBracketedParameterData::default())
+ }
+}
+
+/// A path like `Foo<'a, T>`
+#[derive(Debug, Clone, Eq, PartialEq, Default)]
+pub struct AngleBracketedParameterData {
+ /// The lifetime parameters for this path segment.
+ pub lifetimes: Vec<Lifetime>,
+ /// The type parameters for this path segment, if present.
+ pub types: Vec<Ty>,
+ /// Bindings (equality constraints) on associated types, if present.
+ ///
+ /// E.g., `Foo<A=Bar>`.
+ pub bindings: Vec<TypeBinding>,
+}
+
+/// Bind a type to an associated type: `A=Foo`.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct TypeBinding {
+ pub ident: Ident,
+ pub ty: Ty,
+}
+
+/// A path like `Foo(A,B) -> C`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ParenthesizedParameterData {
+ /// `(A, B)`
+ pub inputs: Vec<Ty>,
+ /// `C`
+ pub output: Option<Ty>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Body {
+ Enum(Vec<Variant>),
+ Struct(Style, Vec<Field>),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Variant {
+ pub ident: Ident,
+ pub attrs: Vec<Attribute>,
+ pub style: Style,
+ pub fields: Vec<Field>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Style {
+ Struct,
+ Tuple,
+ Unit,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Field {
+ pub ident: Option<Ident>,
+ pub vis: Visibility,
+ pub attrs: Vec<Attribute>,
+ pub ty: Ty,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Visibility {
+ Public,
+ Inherited,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Ty {
+ /// A variable-length array (`[T]`)
+ Vec(Box<Ty>),
+ /// A fixed length array (`[T; n]`)
+ FixedLengthVec(Box<Ty>, usize),
+ /// A raw pointer (`*const T` or `*mut T`)
+ Ptr(Box<MutTy>),
+ /// A reference (`&'a T` or `&'a mut T`)
+ Rptr(Option<Lifetime>, Box<MutTy>),
+ /// A bare function (e.g. `fn(usize) -> bool`)
+ BareFn(Box<BareFnTy>),
+ /// The never type (`!`)
+ Never,
+ /// A tuple (`(A, B, C, D, ...)`)
+ Tup(Vec<Ty>),
+ /// A path (`module::module::...::Type`), optionally
+ /// "qualified", e.g. `<Vec<T> as SomeTrait>::SomeType`.
+ ///
+ /// Type parameters are stored in the Path itself
+ Path(Option<QSelf>, Path),
+ /// Something like `A+B`. Note that `B` must always be a path.
+ ObjectSum(Box<Ty>, Vec<TyParamBound>),
+ /// A type like `for<'a> Foo<&'a Bar>`
+ PolyTraitRef(Vec<TyParamBound>),
+ /// An `impl TraitA+TraitB` type.
+ ImplTrait(Vec<TyParamBound>),
+ /// No-op; kept solely so that we can pretty-print faithfully
+ Paren(Box<Ty>),
+ /// TyKind::Infer means the type should be inferred instead of it having been
+ /// specified. This can appear anywhere in a type.
+ Infer,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct MutTy {
+ pub ty: Ty,
+ pub mutbl: Mutability,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Mutability {
+ Mutable,
+ Immutable,
+}
+
+/// The explicit Self type in a "qualified path". The actual
+/// path, including the trait and the associated item, is stored
+/// separately. `position` represents the index of the associated
+/// item qualified with this Self type.
+///
+/// ```rust,ignore
+/// <Vec<T> as a::b::Trait>::AssociatedItem
+/// ^~~~~ ~~~~~~~~~~~~~~^
+/// ty position = 3
+///
+/// <Vec<T>>::AssociatedItem
+/// ^~~~~ ^
+/// ty position = 0
+/// ```
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct QSelf {
+ pub ty: Box<Ty>,
+ pub position: usize
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct BareFnTy {
+ pub lifetimes: Vec<LifetimeDef>,
+ pub decl: FnDecl
+}
+
+/// Header (not the body) of a function declaration.
+///
+/// E.g. `fn foo(bar: baz)`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct FnDecl {
+ pub inputs: Vec<Arg>,
+ pub output: FunctionRetTy,
+}
+
+/// An argument in a function header.
+///
+/// E.g. `bar: usize` as in `fn foo(bar: usize)`
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Arg {
+ pub pat: Option<Ident>,
+ pub ty: Ty,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum FunctionRetTy {
+ /// Return type is not specified.
+ ///
+ /// Functions default to `()` and
+ /// closures default to inference. Span points to where return
+ /// type would be inserted.
+ Default,
+ /// Everything else
+ Ty(Ty),
+}
+
+named!(attribute<&str, Attribute>, chain!(
+ space? ~
+ tag_s!("#[") ~
+ space? ~
+ first: word ~
+ space? ~
+ tag_s!("(") ~
+ inner: separated_list!(tag_s!(", "), word) ~
+ tag_s!(")") ~
+ space? ~
+ tag_s!("]") ,
+ || { return Attribute {
+ value: MetaItem::List(first.to_string(), inner.into_iter().map(|w|
+ MetaItem::Word(w.to_string())
+ ).collect()),
+ is_sugared_doc: false,
+ } }
+));
+
+named!(visibility<&str, Visibility>,
+ map!(opt!(terminated!(tag_s!("pub"), space)), |tag| match tag {
+ Some(_) => Visibility::Public,
+ None => Visibility::Inherited,
+ })
+);
+
+fn ident_ch(ch: char) -> bool {
+ ch.is_alphanumeric() || ch == '_'
+}
+
+named!(word<&str, Ident>, map!(take_while1_s!(ident_ch), String::from));
+
+named!(path_segment<&str, PathSegment>, alt!(
+ chain!(
+ ident: word ~
+ space? ~
+ tag_s!("<") ~
+ types: many0!(ty) ~
+ space? ~
+ tag_s!(">") ,
+ || {
+ PathSegment {
+ ident: ident,
+ parameters: PathParameters::AngleBracketed(
+ AngleBracketedParameterData {
+ lifetimes: Vec::new(),
+ types: types,
+ bindings: Vec::new(),
+ }
+ ),
+ }
+ }
+ )
+ |
+ map!(word, |n| PathSegment::ident(n))
+));
+
+named!(ty<&str, Ty>, chain!(
+ global: tag_s!("::")? ~
+ segments: separated_nonempty_list!(tag_s!("::"), path_segment) ,
+ || {
+ Ty::Path(None, Path {
+ global: global.is_some(),
+ segments: segments,
+ })
+ }
+));
+
+/*
+ /// A variable-length array (`[T]`)
+ Vec(Box<Ty>),
+ /// A fixed length array (`[T; n]`)
+ FixedLengthVec(Box<Ty>, usize),
+ /// A raw pointer (`*const T` or `*mut T`)
+ Ptr(Box<MutTy>),
+ /// A reference (`&'a T` or `&'a mut T`)
+ Rptr(Option<Lifetime>, Box<MutTy>),
+ /// A bare function (e.g. `fn(usize) -> bool`)
+ BareFn(Box<BareFnTy>),
+ /// The never type (`!`)
+ Never,
+ /// A tuple (`(A, B, C, D, ...)`)
+ Tup(Vec<Ty>),
+ /// A path (`module::module::...::Type`), optionally
+ /// "qualified", e.g. `<Vec<T> as SomeTrait>::SomeType`.
+ ///
+ /// Type parameters are stored in the Path itself
+ Path(Option<QSelf>, Path),
+ /// Something like `A+B`. Note that `B` must always be a path.
+ ObjectSum(Box<Ty>, Vec<TyParamBound>),
+ /// A type like `for<'a> Foo<&'a Bar>`
+ PolyTraitRef(Vec<TyParamBound>),
+ /// An `impl TraitA+TraitB` type.
+ ImplTrait(Vec<TyParamBound>),
+ /// No-op; kept solely so that we can pretty-print faithfully
+ Paren(Box<Ty>),
+ /// TyKind::Infer means the type should be inferred instead of it having been
+ /// specified. This can appear anywhere in a type.
+ Infer,
+*/
+
+named!(field<&str, Field>, chain!(
+ space? ~
+ vis: visibility ~
+ ident: word ~
+ space? ~
+ tag_s!(":") ~
+ space? ~
+ ty: ty ,
+ || {
+ Field {
+ ident: Some(ident),
+ vis: vis,
+ attrs: Vec::new(),
+ ty: ty,
+ }
+ }
+));
+
+named!(struct_body<&str, Body>, alt!(
+ chain!(
+ tag_s!("{") ~
+ fields: separated_list!(tag_s!(","), field) ~
+ space? ~
+ tag_s!(",")? ~
+ space? ~
+ tag_s!("}") ,
+ || { Body::Struct(Style::Struct, fields) }
+ )
+ |
+ chain!(
+ tag_s!("(") ~
+ separated_list!(tag_s!(","), chain!(
+ space? ~
+ vis: visibility ~
+ ty: ty ,
+ || {}
+ )) ~
+ space? ~
+ tag_s!(",")? ~
+ space? ~
+ tag_s!(")") ,
+ || { Body::Struct(Style::Tuple, Vec::new()) }
+ )
+ |
+ map!(tag_s!(";"), |_| Body::Struct(Style::Unit, Vec::new()))
+));
+
+named!(item<&str, Item>, chain!(
+ attrs: many0!(attribute) ~
+ space? ~
+ vis: visibility ~
+ tag_s!("struct") ~
+ space ~
+ ident: word ~
+ space? ~
+ body: struct_body ~
+ space? ,
+ || { return Item {
+ ident: ident,
+ vis: vis,
+ attrs: attrs,
+ generics: Generics::default(),
+ body: body,
+ } }
+));
+
+pub fn parse(input: &str) -> Result<Item, String> {
+ match item(input) {
+ IResult::Done(rest, ast) => {
+ if rest.is_empty() {
+ Ok(ast)
+ } else {
+ Err(format!("more than a single input item: {:?}", rest))
+ }
+ }
+ IResult::Error(nom::Err::Code(kind)) |
+ IResult::Error(nom::Err::Node(kind, _)) => {
+ Err(format!("failed to parse {:?}", kind))
+ }
+ IResult::Error(nom::Err::Position(kind, pos)) |
+ IResult::Error(nom::Err::NodePosition(kind, pos, _)) => {
+ Err(format!("failed to parse {:?}: {:?}", kind, pos))
+ }
+ IResult::Incomplete(_) => Err("incomplete input item".to_string()),
+ }
+}