Generic "comment to node" association logic (#4642)

crates/ruff_python_formatter/src/context.rs

@@ -1,24 +1,40 @@
+use crate::comments::Comments;
 use ruff_formatter::{FormatContext, SimpleFormatOptions, SourceCode};
 use ruff_python_ast::source_code::Locator;
+use std::fmt::{Debug, Formatter};
 
-#[derive(Clone, Debug)]
-pub struct ASTFormatContext<'source> {
+#[derive(Clone)]
+pub struct ASTFormatContext<'a> {
     options: SimpleFormatOptions,
-    contents: &'source str,
+    contents: &'a str,
+    comments: Comments<'a>,
 }
 
-impl<'source> ASTFormatContext<'source> {
-    pub fn new(options: SimpleFormatOptions, contents: &'source str) -> Self {
-        Self { options, contents }
+impl<'a> ASTFormatContext<'a> {
+    pub(crate) fn new(
+        options: SimpleFormatOptions,
+        contents: &'a str,
+        comments: Comments<'a>,
+    ) -> Self {
+        Self {
+            options,
+            contents,
+            comments,
+        }
     }
 
-    pub fn contents(&self) -> &'source str {
+    pub fn contents(&self) -> &'a str {
         self.contents
     }
 
-    pub fn locator(&self) -> Locator<'source> {
+    pub fn locator(&self) -> Locator<'a> {
         Locator::new(self.contents)
     }
+
+    #[allow(unused)]
+    pub(crate) fn comments(&self) -> &Comments<'a> {
+        &self.comments
+    }
 }
 
 impl FormatContext for ASTFormatContext<'_> {
@@ -32,3 +48,13 @@ impl FormatContext for ASTFormatContext<'_> {
         SourceCode::new(self.contents)
     }
 }
+
+impl Debug for ASTFormatContext<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ASTFormatContext")
+            .field("options", &self.options)
+            .field("comments", &self.comments.debug(self.source_code()))
+            .field("source", &self.contents)
+            .finish()
+    }
+}