src/item.rs

use super::*;

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Item {
    pub ident: Ident,
    pub vis: Visibility,
    pub attrs: Vec<Attribute>,
    pub generics: Generics,
    pub body: Body,
}

#[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, Copy, 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,
}

#[cfg(feature = "parsing")]
pub mod parsing {
    use super::*;
    use attr::parsing::attribute;
    use common::parsing::{word, visibility};
    use generics::parsing::generics;
    use ty::parsing::ty;
    use nom::multispace;

    named!(pub item<&str, Item>, do_parse!(
        attrs: many0!(attribute) >>
        vis: visibility >>
        which: alt!(tag_s!("struct") | tag_s!("enum")) >>
        multispace >>
        ident: word >>
        generics: generics >>
        item: switch!(value!(which),
            "struct" => map!(struct_body, move |(style, fields)| Item {
                ident: ident,
                vis: vis,
                attrs: attrs,
                generics: generics,
                body: Body::Struct(style, fields),
            })
            |
            "enum" => map!(enum_body, move |body| Item {
                ident: ident,
                vis: vis,
                attrs: attrs,
                generics: generics,
                body: body,
            })
        ) >>
        opt!(multispace) >>
        (item)
    ));

    named!(struct_body<&str, (Style, Vec<Field>)>, alt!(
        struct_like_body => { |fields| (Style::Struct, fields) }
        |
        terminated!(tuple_like_body, punct!(";")) => { |fields| (Style::Tuple, fields) }
        |
        punct!(";") => { |_| (Style::Unit, Vec::new()) }
    ));

    named!(enum_body<&str, Body>, do_parse!(
        punct!("{") >>
        variants: separated_list!(punct!(","), variant) >>
        opt!(punct!(",")) >>
        punct!("}") >>
        (Body::Enum(variants))
    ));

    named!(variant<&str, Variant>, do_parse!(
        attrs: many0!(attribute) >>
        ident: word >>
        body: alt!(
            struct_like_body => { |fields| (Style::Struct, fields) }
            |
            tuple_like_body => { |fields| (Style::Tuple, fields) }
            |
            epsilon!() => { |_| (Style::Unit, Vec::new()) }
        ) >>
        (Variant {
            ident: ident,
            attrs: attrs,
            style: body.0,
            fields: body.1,
        })
    ));

    named!(struct_like_body<&str, Vec<Field> >, do_parse!(
        punct!("{") >>
        fields: separated_list!(punct!(","), struct_field) >>
        opt!(punct!(",")) >>
        punct!("}") >>
        (fields)
    ));

    named!(tuple_like_body<&str, Vec<Field> >, do_parse!(
        punct!("(") >>
        fields: separated_list!(punct!(","), tuple_field) >>
        opt!(punct!(",")) >>
        punct!(")") >>
        (fields)
    ));

    named!(struct_field<&str, Field>, do_parse!(
        attrs: many0!(attribute) >>
        vis: visibility >>
        ident: word >>
        punct!(":") >>
        ty: ty >>
        (Field {
            ident: Some(ident),
            vis: vis,
            attrs: attrs,
            ty: ty,
        })
    ));

    named!(tuple_field<&str, Field>, do_parse!(
        attrs: many0!(attribute) >>
        vis: visibility >>
        ty: ty >>
        (Field {
            ident: None,
            vis: vis,
            attrs: attrs,
            ty: ty,
        })
    ));
}

#[cfg(feature = "printing")]
mod printing {
    use super::*;
    use common::Visibility;
    use quote::{Tokens, ToTokens};

    impl ToTokens for Item {
        fn to_tokens(&self, tokens: &mut Tokens) {
            for attr in &self.attrs {
                attr.to_tokens(tokens);
            }
            if let Visibility::Public = self.vis {
                tokens.append("pub");
            }
            match self.body {
                Body::Enum(_) => tokens.append("enum"),
                Body::Struct(_, _) => tokens.append("struct"),
            }
            self.ident.to_tokens(tokens);
            self.generics.to_tokens(tokens);
            self.body.to_tokens(tokens);
        }
    }

    impl ToTokens for Body {
        fn to_tokens(&self, tokens: &mut Tokens) {
            match *self {
                Body::Enum(ref variants) => {
                    tokens.append("{");
                    for variant in variants {
                        variant.to_tokens(tokens);
                    }
                    tokens.append("}");
                }
                Body::Struct(style, ref fields) => {
                    fields_to_tokens(style, fields, tokens);
                    match style {
                        Style::Struct => { /* no semicolon */ }
                        Style::Tuple | Style::Unit => tokens.append(";"),
                    }
                }
            }
        }
    }

    impl ToTokens for Variant {
        fn to_tokens(&self, tokens: &mut Tokens) {
            for attr in &self.attrs {
                attr.to_tokens(tokens);
            }
            self.ident.to_tokens(tokens);
            fields_to_tokens(self.style, &self.fields, tokens);
        }
    }

    impl ToTokens for Field {
        fn to_tokens(&self, tokens: &mut Tokens) {
            for attr in &self.attrs {
                attr.to_tokens(tokens);
            }
            if let Visibility::Public = self.vis {
                tokens.append("pub");
            }
            if let Some(ref ident) = self.ident {
                ident.to_tokens(tokens);
                tokens.append(":");
            }
            self.ty.to_tokens(tokens);
        }
    }

    fn fields_to_tokens(style: Style, fields: &[Field], tokens: &mut Tokens) {
        match style {
            Style::Struct => {
                tokens.append("{");
                tokens.append_separated(fields, ",");
                tokens.append("}");
            }
            Style::Tuple => {
                tokens.append("(");
                tokens.append_separated(fields, ",");
                tokens.append(")");
            }
            Style::Unit => {
                assert!(fields.is_empty(), "unit variant cannot have fields");
            }
        }
    }
}