Polish dump-ast example code
diff --git a/examples/dump-syntax/Cargo.toml b/examples/dump-syntax/Cargo.toml
new file mode 100644
index 0000000..39d9622
--- /dev/null
+++ b/examples/dump-syntax/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "dump-syntax"
+version = "0.0.0"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
+publish = false
+
+[dependencies]
+syn = { path = "../..", features = ["full", "extra-traits"] }
+
+[[bin]]
+name = "dump-syntax"
+path = "main.rs"
diff --git a/examples/dump-syntax/README.md b/examples/dump-syntax/README.md
new file mode 100644
index 0000000..3b23736
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+++ b/examples/dump-syntax/README.md
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+Parse a Rust source file into a `syn::File` and print out a debug representation
+of the syntax tree.
+
+Use the following command from this directory to test this program by running it
+on its own source code:
+
+```
+cargo run -- main.rs
+```
+
+The output will begin with:
+
+```
+File {
+ shebang: None,
+ attrs: [
+ Attribute {
+ pound_token: Pound,
+ style: Inner(
+ Bang
+ ),
+ bracket_token: Bracket,
+ path: Path {
+ leading_colon: None,
+ segments: [
+ ...
+}
+```
diff --git a/examples/dump-syntax/main.rs b/examples/dump-syntax/main.rs
new file mode 100644
index 0000000..584fe3c
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+++ b/examples/dump-syntax/main.rs
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+//! Parse a Rust source file into a `syn::File` and print out a debug
+//! representation of the syntax tree.
+//!
+//! Use the following command from this directory to test this program by
+//! running it on its own source code:
+//!
+//! cargo run -- main.rs
+//!
+//! The output will begin with:
+//!
+//! File {
+//! shebang: None,
+//! attrs: [
+//! Attribute {
+//! pound_token: Pound,
+//! style: Inner(
+//! ...
+//! }
+
+extern crate syn;
+
+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");
+ println!("{:#?}", syntax);
+}