[parser] Simple REPL that parses input and prints output

parser/src/main.rs

@@ -5,13 +5,32 @@
 extern crate sibillexer;
 extern crate sibilparser;
 
+use std::io::prelude::*;
+use std::io;
 use sibillexer::Lexer;
 use sibilparser::Parser;
 
 fn main() {
-    let lexer = Lexer::new("(ab)".chars());
-    let parser = Parser::new(lexer);
-    for thing in parser {
-        println!("main: token -> {:?}", thing);
+    loop {
+        // Print a prompt.
+        print!("> ");
+        io::stdout().flush().ok().expect("couldn't flush");
+
+        // Read a line from stdin.
+        let mut input = String::new();
+        io::stdin().read_line(&mut input).unwrap();
+
+        // Remove the trailing newline.
+        input.pop();
+
+        // Create a lexer and parser and process the input.
+        let lexer = Lexer::new(input.chars());
+        let parser = Parser::new(lexer);
+
+        // Print the parser's output.
+        for thing in parser {
+            println!("{:?}", thing);
+        }
+        println!();
     }
 }