syn 0.8.0

use super::*;

/// An item
///
/// The name might be a dummy name in case of anonymous items
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Item {
    pub ident: Ident,
    pub vis: Visibility,
    pub attrs: Vec<Attribute>,
    pub node: ItemKind,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub enum ItemKind {
    /// An`extern crate` item, with optional original crate name.
    ///
    /// E.g. `extern crate foo` or `extern crate foo_bar as foo`
    ExternCrate(Option<Ident>),
    /// A use declaration (`use` or `pub use`) item.
    ///
    /// E.g. `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`
    Use(Box<ViewPath>),
    /// A static item (`static` or `pub static`).
    ///
    /// E.g. `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`
    Static(Box<Ty>, Mutability, Box<Expr>),
    /// A constant item (`const` or `pub const`).
    ///
    /// E.g. `const FOO: i32 = 42;`
    Const(Box<Ty>, Box<Expr>),
    /// A function declaration (`fn` or `pub fn`).
    ///
    /// E.g. `fn foo(bar: usize) -> usize { .. }`
    Fn(Box<FnDecl>, Unsafety, Constness, Abi, Generics, Box<Block>),
    /// A module declaration (`mod` or `pub mod`).
    ///
    /// E.g. `mod foo;` or `mod foo { .. }`
    Mod(Vec<Item>),
    /// An external module (`extern` or `pub extern`).
    ///
    /// E.g. `extern {}` or `extern "C" {}`
    ForeignMod(ForeignMod),
    /// A type alias (`type` or `pub type`).
    ///
    /// E.g. `type Foo = Bar<u8>;`
    Ty(Box<Ty>, Generics),
    /// An enum definition (`enum` or `pub enum`).
    ///
    /// E.g. `enum Foo<A, B> { C<A>, D<B> }`
    Enum(Vec<Variant>, Generics),
    /// A struct definition (`struct` or `pub struct`).
    ///
    /// E.g. `struct Foo<A> { x: A }`
    Struct(VariantData, Generics),
    /// A union definition (`union` or `pub union`).
    ///
    /// E.g. `union Foo<A, B> { x: A, y: B }`
    Union(VariantData, Generics),
    /// A Trait declaration (`trait` or `pub trait`).
    ///
    /// E.g. `trait Foo { .. }` or `trait Foo<T> { .. }`
    Trait(Unsafety, Generics, Vec<TyParamBound>, Vec<TraitItem>),
    // Default trait implementation.
    ///
    /// E.g. `impl Trait for .. {}` or `impl<T> Trait<T> for .. {}`
    DefaultImpl(Unsafety, Path),
    /// An implementation.
    ///
    /// E.g. `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`
    Impl(Unsafety,
             ImplPolarity,
             Generics,
             Option<Path>, // (optional) trait this impl implements
             Box<Ty>, // self
             Vec<ImplItem>),
    /// A macro invocation (which includes macro definition).
    ///
    /// E.g. `macro_rules! foo { .. }` or `foo!(..)`
    Mac(Mac),
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub enum ViewPath {
    /// `foo::bar::baz as quux`
    ///
    /// or just
    ///
    /// `foo::bar::baz` (with `as baz` implicitly on the right)
    Simple(Ident, Path),

    /// `foo::bar::*`
    Glob(Path),

    /// `foo::bar::{a, b, c}`
    List(Path, Vec<PathListItem>)
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct PathListItem {
    pub name: Ident,
    /// renamed in list, e.g. `use foo::{bar as baz};`
    pub rename: Option<Ident>,
}

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum Unsafety {
    Unsafe,
    Normal,
}

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum Constness {
    Const,
    NotConst,
}

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum Defaultness {
    Default,
    Final,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Abi(pub String);

/// Foreign module declaration.
///
/// E.g. `extern { .. }` or `extern C { .. }`
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct ForeignMod {
    pub abi: Abi,
    pub items: Vec<ForeignItem>,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct ForeignItem {
    pub ident: Ident,
    pub attrs: Vec<Attribute>,
    pub node: ForeignItemKind,
    pub vis: Visibility,
}

/// An item within an `extern` block
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum ForeignItemKind {
    /// A foreign function
    Fn(Box<FnDecl>, Generics),
    /// A foreign static item (`static ext: u8`), with optional mutability
    /// (the boolean is true when mutable)
    Static(Box<Ty>, bool),
}

/// Represents an item declaration within a trait declaration,
/// possibly including a default implementation. A trait item is
/// either required (meaning it doesn't have an implementation, just a
/// signature) or provided (meaning it has a default implementation).
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct TraitItem {
    pub ident: Ident,
    pub attrs: Vec<Attribute>,
    pub node: TraitItemKind,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub enum TraitItemKind {
    Const(Ty, Option<Expr>),
    Method(MethodSig, Option<Block>),
    Type(Vec<TyParamBound>, Option<Ty>),
    Macro(Mac),
}

#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum ImplPolarity {
    /// `impl Trait for Type`
    Positive,
    /// `impl !Trait for Type`
    Negative,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct ImplItem {
    pub ident: Ident,
    pub vis: Visibility,
    pub defaultness: Defaultness,
    pub attrs: Vec<Attribute>,
    pub node: ImplItemKind,
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub enum ImplItemKind {
    Const(Ty, Expr),
    Method(MethodSig, Block),
    Type(Ty),
    Macro(Mac),
}

/// Represents a method's signature in a trait declaration,
/// or in an implementation.
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct MethodSig {
    pub unsafety: Unsafety,
    pub constness: Constness,
    pub abi: Abi,
    pub decl: FnDecl,
    pub generics: Generics,
}

#[cfg(feature = "parsing")]
pub mod parsing {
    use super::*;
    use attr::parsing::attribute;
    use data::parsing::visibility;
    use ident::parsing::ident;
    use macro_input::{Body, MacroInput};
    use macro_input::parsing::macro_input;
    use nom::multispace;

    named!(pub item -> Item, alt!(
        item_extern_crate
        // TODO: Use
        // TODO: Static
        // TODO: Const
        // TODO: Fn
        // TODO: Mod
        // TODO: ForeignMod
        // TODO: Ty
        |
        item_struct_or_enum
        // TODO: Union
        // TODO: Trait
        // TODO: DefaultImpl
        // TODO: Impl
        // TODO: Mac
    ));

    named!(item_extern_crate -> Item, do_parse!(
        attrs: many0!(attribute) >>
        vis: visibility >>
        punct!("extern") >>
        multispace >>
        punct!("crate") >>
        multispace >>
        id: ident >>
        rename: option!(preceded!(
            tuple!(punct!("as"), multispace),
            ident
        )) >>
        punct!(";") >>
        ({
            let (name, original_name) = match rename {
                Some(rename) => (rename, Some(id)),
                None => (id, None),
            };
            Item {
                ident: name,
                vis: vis,
                attrs: attrs,
                node: ItemKind::ExternCrate(original_name),
            }
        })
    ));

    named!(item_struct_or_enum -> Item, map!(
        macro_input,
        |def: MacroInput| Item {
            ident: def.ident,
            vis: def.vis,
            attrs: def.attrs,
            node: match def.body {
                Body::Enum(variants) => {
                    ItemKind::Enum(variants, def.generics)
                }
                Body::Struct(variant_data) => {
                    ItemKind::Struct(variant_data, def.generics)
                }
            }
        }
    ));
}