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
use crate::attr::Attribute;
use crate::item::Item;

ast_struct! {
    /// A complete file of Rust source code.
    ///
    /// Typically `File` objects are created with [`parse_file`].
    ///
    /// [`parse_file`]: crate::parse_file
    ///
    /// # Example
    ///
    /// Parse a Rust source file into a `syn::File` and print out a debug
    /// representation of the syntax tree.
    ///
    /// ```
    /// use std::env;
    /// use std::fs::File;
    /// use std::io::Read;
    /// use std::process;
    ///
    /// fn main() {
    /// # }
    /// #
    /// # fn fake_main() {
    ///     let mut args = env::args();
    ///     let _ = args.next(); // executable name
    ///
    ///     let filename = match (args.next(), args.next()) {
    ///         (Some(filename), None) => filename,
    ///         _ => {
    ///             eprintln!("Usage: dump-syntax path/to/filename.rs");
    ///             process::exit(1);
    ///         }
    ///     };
    ///
    ///     let mut file = File::open(&filename).expect("Unable to open file");
    ///
    ///     let mut src = String::new();
    ///     file.read_to_string(&mut src).expect("Unable to read file");
    ///
    ///     let syntax = syn::parse_file(&src).expect("Unable to parse file");
    ///
    ///     // Debug impl is available if Syn is built with "extra-traits" feature.
    ///     println!("{:#?}", syntax);
    /// }
    /// ```
    ///
    /// Running with its own source code as input, this program prints output
    /// that begins with:
    ///
    /// ```text
    /// File {
    ///     shebang: None,
    ///     attrs: [],
    ///     items: [
    ///         Use(
    ///             ItemUse {
    ///                 attrs: [],
    ///                 vis: Inherited,
    ///                 use_token: Use,
    ///                 leading_colon: None,
    ///                 tree: Path(
    ///                     UsePath {
    ///                         ident: Ident(
    ///                             std,
    ///                         ),
    ///                         colon2_token: Colon2,
    ///                         tree: Name(
    ///                             UseName {
    ///                                 ident: Ident(
    ///                                     env,
    ///                                 ),
    ///                             },
    ///                         ),
    ///                     },
    ///                 ),
    ///                 semi_token: Semi,
    ///             },
    ///         ),
    /// ...
    /// ```
    #[cfg_attr(doc_cfg, doc(cfg(feature = "full")))]
    pub struct File {
        pub shebang: Option<String>,
        pub attrs: Vec<Attribute>,
        pub items: Vec<Item>,
    }
}

#[cfg(feature = "parsing")]
pub(crate) mod parsing {
    use crate::attr::Attribute;
    use crate::error::Result;
    use crate::file::File;
    use crate::parse::{Parse, ParseStream};

    #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
    impl Parse for File {
        fn parse(input: ParseStream) -> Result<Self> {
            Ok(File {
                shebang: None,
                attrs: input.call(Attribute::parse_inner)?,
                items: {
                    let mut items = Vec::new();
                    while !input.is_empty() {
                        items.push(input.parse()?);
                    }
                    items
                },
            })
        }
    }
}

#[cfg(feature = "printing")]
mod printing {
    use crate::attr::FilterAttrs;
    use crate::file::File;
    use proc_macro2::TokenStream;
    use quote::{ToTokens, TokenStreamExt};

    #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
    impl ToTokens for File {
        fn to_tokens(&self, tokens: &mut TokenStream) {
            tokens.append_all(self.attrs.inner());
            tokens.append_all(&self.items);
        }
    }
}