1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

use super::*;
use proc_macro2::TokenStream;
#[cfg(feature = "parsing")]
use proc_macro2::{Delimiter, TokenTree};
use token::{Brace, Bracket, Paren};

#[cfg(feature = "parsing")]
use parse::{ParseStream, Result};
#[cfg(feature = "extra-traits")]
use std::hash::{Hash, Hasher};
#[cfg(feature = "extra-traits")]
use tt::TokenStreamHelper;

ast_struct! {
    /// A macro invocation: `println!("{}", mac)`.
    ///
    /// *This type is available if Syn is built with the `"derive"` or `"full"`
    /// feature.*
    pub struct Macro #manual_extra_traits {
        pub path: Path,
        pub bang_token: Token![!],
        pub delimiter: MacroDelimiter,
        pub tts: TokenStream,
    }
}

ast_enum! {
    /// A grouping token that surrounds a macro body: `m!(...)` or `m!{...}` or `m![...]`.
    ///
    /// *This type is available if Syn is built with the `"derive"` or `"full"`
    /// feature.*
    pub enum MacroDelimiter {
        Paren(Paren),
        Brace(Brace),
        Bracket(Bracket),
    }
}

#[cfg(feature = "extra-traits")]
impl Eq for Macro {}

#[cfg(feature = "extra-traits")]
impl PartialEq for Macro {
    fn eq(&self, other: &Self) -> bool {
        self.path == other.path
            && self.bang_token == other.bang_token
            && self.delimiter == other.delimiter
            && TokenStreamHelper(&self.tts) == TokenStreamHelper(&other.tts)
    }
}

#[cfg(feature = "extra-traits")]
impl Hash for Macro {
    fn hash<H>(&self, state: &mut H)
    where
        H: Hasher,
    {
        self.path.hash(state);
        self.bang_token.hash(state);
        self.delimiter.hash(state);
        TokenStreamHelper(&self.tts).hash(state);
    }
}

#[cfg(feature = "parsing")]
pub fn parse_delimiter(input: ParseStream) -> Result<(MacroDelimiter, TokenStream)> {
    input.step(|cursor| {
        if let Some((TokenTree::Group(g), rest)) = cursor.token_tree() {
            let span = g.span();
            let delimiter = match g.delimiter() {
                Delimiter::Parenthesis => MacroDelimiter::Paren(Paren(span)),
                Delimiter::Brace => MacroDelimiter::Brace(Brace(span)),
                Delimiter::Bracket => MacroDelimiter::Bracket(Bracket(span)),
                Delimiter::None => {
                    return Err(cursor.error("expected delimiter"));
                }
            };
            Ok(((delimiter, g.stream().clone()), rest))
        } else {
            Err(cursor.error("expected delimiter"))
        }
    })
}

#[cfg(feature = "parsing")]
pub mod parsing {
    use super::*;

    use parse::{Parse, ParseStream, Result};

    impl Parse for Macro {
        fn parse(input: ParseStream) -> Result<Self> {
            let tts;
            Ok(Macro {
                path: input.call(Path::parse_mod_style)?,
                bang_token: input.parse()?,
                delimiter: {
                    let (delimiter, content) = parse_delimiter(input)?;
                    tts = content;
                    delimiter
                },
                tts: tts,
            })
        }
    }
}

#[cfg(feature = "printing")]
mod printing {
    use super::*;
    use proc_macro2::TokenStream;
    use quote::ToTokens;

    impl ToTokens for Macro {
        fn to_tokens(&self, tokens: &mut TokenStream) {
            self.path.to_tokens(tokens);
            self.bang_token.to_tokens(tokens);
            match self.delimiter {
                MacroDelimiter::Paren(ref paren) => {
                    paren.surround(tokens, |tokens| self.tts.to_tokens(tokens));
                }
                MacroDelimiter::Brace(ref brace) => {
                    brace.surround(tokens, |tokens| self.tts.to_tokens(tokens));
                }
                MacroDelimiter::Bracket(ref bracket) => {
                    bracket.surround(tokens, |tokens| self.tts.to_tokens(tokens));
                }
            }
        }
    }
}