rust parser with LALRPOP: pascal example

This is all just code from the LALRPOP library docs.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/bin/parse_pascal.rs b/src/bin/parse_pascal.rs
new file mode 100644
index 0000000..7b08f36
--- /dev/null
+++ b/src/bin/parse_pascal.rs
@@ -0,0 +1,47 @@
+
+extern crate modelthing;
+extern crate rustc_serialize;
+extern crate docopt;
+
+use modelthing::pascal;
+use docopt::Docopt;
+use std::env;
+use std::io::Read;
+use std::fs::File;
+use std::time::Instant;
+
+
+fn main() {
+    let args: Args = Docopt::new(USAGE)
+                        .and_then(|d| d.argv(env::args()).decode())
+                        .unwrap_or_else(|e| e.exit());
+
+    for input in &args.arg_inputs {
+        let mut s = String::new();
+        if let Err(err) = File::open(input).and_then(|mut f| f.read_to_string(&mut s)) {
+            println!("Input `{}`: I/O Error {}",
+                     input, err);
+            continue;
+        }
+
+        let time_stamp = Instant::now();
+        let result = pascal::parse_file(&s);
+        let elapsed = time_stamp.elapsed();
+        let elapsed = elapsed.as_secs() as f64 + elapsed.subsec_nanos() as f64 / 1000_000_000.0;
+
+        match result {
+            Ok(()) => println!("Input `{}` ({}s): OK", input, elapsed),
+            Err(err) => println!("Input `{}` ({}s): parse error {:?}", input, elapsed, err),
+        }
+    }
+}
+
+const USAGE: &'static str = "
+Usage: modelthing-pascal <inputs>...
+Parses each input file.
+";
+
+#[derive(Debug, RustcDecodable)]
+struct Args {
+    arg_inputs: Vec<String>,
+}