Proof of concept parsing: print all labels

src/labels/labels.rs

@@ -1,8 +1,25 @@
 use crate::{
-    preprocess::peg::{Alt, And, Dot, EOF, Not, Opt, Rule, Star},
+    preprocess::peg::{Alt, And, Dot, EOF, Not, Opt, Parser, Rule, Star, Tag},
     star,
+    world::Stat,
 };
 
+pub fn print_labels(b: &Stat) {
+    let mut parser = Parser::new(&b.code);
+    if !parse_program().parse(&mut parser) {
+        eprintln!("Couldn't parse stat's code: {:?}", b.code);
+        return;
+    }
+
+    for group in parser.iter() {
+        if group.event.kind == "label" {
+            let span = group.event.span.clone();
+            let s = &b.code[span];
+            println!("- {}", s);
+        }
+    }
+}
+
 fn parse_program() -> impl Rule {
     (Opt((parse_line, star!(("\n", parse_line)))), EOF)
 }
@@ -17,7 +34,7 @@ fn parse_any_line() -> impl Rule {
 
 fn parse_label_line() -> impl Rule {
     let allowed = Alt(('A'..='Z', 'a'..='z', '0'..='9', "_", "@", "~"));
-    (":", star!(allowed), eol)
+    (":", Tag("label", star!(allowed)), eol)
 }
 
 fn eol() -> impl Rule {

src/main.rs

@@ -4,6 +4,7 @@ mod preprocess;
 mod world;
 
 use anyhow::anyhow;
+use labels::labels::print_labels;
 use preprocess::eval::Context;
 use std::{env, error::Error, fs, path::PathBuf, process::exit};
 use world::World;
@@ -46,6 +47,13 @@ fn main() -> Result<(), Box<dyn Error>> {
         board.name.push_str(" (♪)");
     }
 
+    for board in &world.boards {
+        println!("# Board: {}", board.name);
+        for stat in &board.stats {
+            print_labels(stat);
+        }
+    }
+
     // Try to write a modified world file
     fs::write("tmp.zzt", world.to_bytes()?)?;