FEATURE: Show line numbers for ucg statements in the repl.

src/io/mod.rs

@@ -24,6 +24,10 @@ impl StatementAccumulator {
         Self { acc: Vec::new() }
     }
 
+    pub fn next_line(&self) -> usize {
+        self.acc.len() + 1
+    }
+
     /// Tells you if the latest line ends in the statement terminator.
     ///
     /// Returns None if it wasn't a terminated statement and leaves the

src/main.rs

@@ -551,9 +551,11 @@ fn do_repl(
     let mut builder = build::FileBuilder::new(std::env::current_dir()?, import_paths, cache);
     // loop
     let mut lines = ucglib::io::StatementAccumulator::new();
+    println!("Welcome to the UCG repl. Ctrl-D to exit");
+    println!("");
     loop {
         // print prompt
-        lines.push(editor.readline("ucg> ")?);
+        lines.push(editor.readline(&format!("{}> ", lines.next_line()))?);
         // check to see if that line is a statement
         loop {
             // read a statement
@@ -573,7 +575,7 @@ fn do_repl(
                 break;
             }
             // if not then keep accumulating lines without a prompt
-            lines.push(editor.readline(">>   ")?);
+            lines.push(editor.readline(&format!("{}> ", lines.next_line()))?);
         }
     }
 }