Partial implementation of anonymous labels

src/labels/parse.rs

@@ -8,8 +8,11 @@ use crate::{peg::ParseState, world::Stat};
 pub type ParsedStat = Vec<Chunk>;
 pub enum Chunk {
     Verbatim(String),
-    Label(LabelName),
-    Reference(LabelName),
+    Label {
+        is_ref: bool,
+        is_anon: bool,
+        name: LabelName,
+    },
 }
 
 #[derive(Clone, Debug, Default)]
@@ -44,22 +47,22 @@ pub fn parse_stat_labels(stat: &Stat) -> ParsedStat {
     // Convert #Labels into (span, chunk) pairs
     let span_chunks = label_captures.iter().map(|(tag, cap)| {
         let mut name = LabelName::default();
+        let mut is_anon = false;
         for child in cap.children() {
             match child.kind() {
-                Tag::Namespace => {
-                    name.namespace = Some(child.text().into());
-                }
-                Tag::Global => {
+                Tag::Namespace => name.namespace = Some(child.text().into()),
+                Tag::Anon | Tag::Global => {
                     name.name = child.text().into();
+                    is_anon = child.kind() == Tag::Anon;
                 }
                 Tag::Local => name.local = Some(child.text().into()),
-                _ => unimplemented!(),
+                _ => unreachable!(),
             }
         }
-        let chunk = match tag {
-            Tag::Label => Chunk::Label(name),
-            Tag::Reference => Chunk::Reference(name),
-            _ => unimplemented!(),
+        let chunk = Chunk::Label {
+            is_ref: *tag == Tag::Reference,
+            is_anon,
+            name,
         };
         (cap.span(), chunk)
     });

src/labels/process.rs

@@ -19,7 +19,11 @@ pub fn process_labels(board: &mut Board) {
         for chunk in stat.iter_mut() {
             match chunk {
                 Chunk::Verbatim(_) => {}
-                Chunk::Label(name) | Chunk::Reference(name) => {
+                Chunk::Label {
+                    name,
+                    is_ref: _,
+                    is_anon: _,
+                } => {
                     let sanitized = registry.sanitize(name);
                     *chunk = Chunk::Verbatim(sanitized.into());
                 }
@@ -27,15 +31,78 @@ pub fn process_labels(board: &mut Board) {
         }
     }
 
+    anonymous_forward_pass(&mut stats, &mut registry);
+    anonymous_backward_pass(&mut stats);
+
     // Join chunks together and replace old stats' code
     for (old_stat, parsed_stat) in board.stats.iter_mut().zip(stats.into_iter()) {
         let new_code = parsed_stat
             .into_iter()
             .map(|chunk| match chunk {
                 Chunk::Verbatim(s) => s,
-                _ => unreachable!(),
+                _ => unimplemented!(),
             })
             .collect();
         old_stat.code = new_code;
     }
 }
+
+fn anonymous_forward_pass(stats: &mut [ParsedStat], registry: &mut Registry) {
+    let mut label_names = vec![];
+    for stat in stats.iter_mut() {
+        let mut i = 0;
+        for chunk in stat.iter_mut() {
+            match chunk {
+                Chunk::Label {
+                    is_ref: false,
+                    is_anon: true,
+                    name,
+                } => {
+                    if i == label_names.len() {
+                        label_names.push(registry.gen_anonymous());
+                    }
+                    name.name = label_names[i].clone();
+                    i += 1;
+                }
+                Chunk::Label {
+                    is_ref: true,
+                    is_anon: true,
+                    name,
+                } => {
+                    if name.name == "@b" {
+                        // TODO: a more explicit check that a "before" label exists
+                        name.name = label_names[i - 1].clone();
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}
+
+fn anonymous_backward_pass(stats: &mut [ParsedStat]) {
+    for stat in stats.iter_mut() {
+        let mut last_name = None;
+        for chunk in stat.iter_mut().rev() {
+            match chunk {
+                Chunk::Label {
+                    is_ref: false,
+                    is_anon: true,
+                    name,
+                } => {
+                    last_name = Some(name.name.clone());
+                }
+                Chunk::Label {
+                    is_ref: true,
+                    is_anon: true,
+                    name,
+                } => {
+                    if name.name == "@f" {
+                        name.name = last_name.clone().unwrap();
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}