Refactor Options representation (#7591)

crates/ruff_dev/src/generate_options.rs

@@ -1,9 +1,68 @@
 //! Generate a Markdown-compatible listing of configuration options for `pyproject.toml`.
 //!
 //! Used for <https://docs.astral.sh/ruff/settings/>.
-use itertools::Itertools;
+use std::fmt::Write;
+
 use ruff_workspace::options::Options;
-use ruff_workspace::options_base::{OptionEntry, OptionField};
+use ruff_workspace::options_base::{OptionField, OptionSet, OptionsMetadata, Visit};
+
+pub(crate) fn generate() -> String {
+    let mut output = String::new();
+    generate_set(&mut output, &Set::Toplevel(Options::metadata()));
+
+    output
+}
+
+fn generate_set(output: &mut String, set: &Set) {
+    writeln!(output, "### {title}\n", title = set.title()).unwrap();
+
+    let mut visitor = CollectOptionsVisitor::default();
+    set.metadata().record(&mut visitor);
+
+    let (mut fields, mut sets) = (visitor.fields, visitor.groups);
+
+    fields.sort_unstable_by(|(name, _), (name2, _)| name.cmp(name2));
+    sets.sort_unstable_by(|(name, _), (name2, _)| name.cmp(name2));
+
+    // Generate the fields.
+    for (name, field) in &fields {
+        emit_field(output, name, field, set.name());
+        output.push_str("---\n\n");
+    }
+
+    // Generate all the sub-sets.
+    for (set_name, sub_set) in &sets {
+        generate_set(output, &Set::Named(set_name, *sub_set));
+    }
+}
+
+enum Set<'a> {
+    Toplevel(OptionSet),
+    Named(&'a str, OptionSet),
+}
+
+impl<'a> Set<'a> {
+    fn name(&self) -> Option<&'a str> {
+        match self {
+            Set::Toplevel(_) => None,
+            Set::Named(name, _) => Some(name),
+        }
+    }
+
+    fn title(&self) -> &'a str {
+        match self {
+            Set::Toplevel(_) => "Top-level",
+            Set::Named(name, _) => name,
+        }
+    }
+
+    fn metadata(&self) -> &OptionSet {
+        match self {
+            Set::Toplevel(set) => set,
+            Set::Named(_, set) => set,
+        }
+    }
+}
 
 fn emit_field(output: &mut String, name: &str, field: &OptionField, group_name: Option<&str>) {
     // if there's a group name, we need to add it to the anchor
@@ -37,38 +96,18 @@ fn emit_field(output: &mut String, name: &str, field: &OptionField, group_name:
     output.push('\n');
 }
 
-pub(crate) fn generate() -> String {
-    let mut output: String = "### Top-level\n\n".into();
-
-    let sorted_options: Vec<_> = Options::metadata()
-        .into_iter()
-        .sorted_by_key(|(name, _)| *name)
-        .collect();
-
-    // Generate all the top-level fields.
-    for (name, entry) in &sorted_options {
-        let OptionEntry::Field(field) = entry else {
-            continue;
-        };
-        emit_field(&mut output, name, field, None);
-        output.push_str("---\n\n");
-    }
-
-    // Generate all the sub-groups.
-    for (group_name, entry) in &sorted_options {
-        let OptionEntry::Group(fields) = entry else {
-            continue;
-        };
-        output.push_str(&format!("### {group_name}\n"));
-        output.push('\n');
-        for (name, entry) in fields.iter().sorted_by_key(|(name, _)| name) {
-            let OptionEntry::Field(field) = entry else {
-                continue;
-            };
-            emit_field(&mut output, name, field, Some(group_name));
-            output.push_str("---\n\n");
-        }
-    }
-
-    output
+#[derive(Default)]
+struct CollectOptionsVisitor {
+    groups: Vec<(String, OptionSet)>,
+    fields: Vec<(String, OptionField)>,
+}
+
+impl Visit for CollectOptionsVisitor {
+    fn record_set(&mut self, name: &str, group: OptionSet) {
+        self.groups.push((name.to_owned(), group));
+    }
+
+    fn record_field(&mut self, name: &str, field: OptionField) {
+        self.fields.push((name.to_owned(), field));
+    }
 }