Expand description
A complete file of Rust source code.
Typically File
objects are created with 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() {
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:
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,
},
),
...
Fields§
§shebang: Option<String>
§attrs: Vec<Attribute>
§items: Vec<Item>
Trait Implementations§
source§impl ToTokens for File
impl ToTokens for File
source§fn to_tokens(&self, tokens: &mut TokenStream)
fn to_tokens(&self, tokens: &mut TokenStream)
source§fn to_token_stream(&self) -> TokenStream
fn to_token_stream(&self) -> TokenStream
source§fn into_token_stream(self) -> TokenStreamwhere
Self: Sized,
fn into_token_stream(self) -> TokenStreamwhere
Self: Sized,
Auto Trait Implementations§
impl RefUnwindSafe for File
impl !Send for File
impl !Sync for File
impl Unpin for File
impl UnwindSafe for File
Blanket Implementations§
source§impl<T> Spanned for Twhere
T: Spanned + ?Sized,
impl<T> Spanned for Twhere
T: Spanned + ?Sized,
source§fn span(&self) -> Span
fn span(&self) -> Span
Returns a
Span
covering the complete contents of this syntax tree
node, or Span::call_site()
if this node is empty.